121121 crdamc hvac design analysis

Carl R. Darnall Army Medical Center Replacement IFC SUBMITTAL FORT HOOD, TEXAS / PN74650 / 74728 DP-5 12 DECEMBER, 2012

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BALFOUR BEATTY : McCARTHY Joint Venture HVAC

HKS, Inc. / WINGLER & SHARP PART 6-1

6.1 Overall HVAC System Concept

6.2 Performance Criteria

6.3 System Design Standard

6.4 HVAC System Description


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6.1 Overall HVAC System Concept

The HVAC system selection for the Carl R. Darnall Army Medical Center Replacement (CRDAMCR) was driven by the following broad criteria:

Optimize the healing environment

Sustainable system choices and layouts that provide flexibility to accommodate future change

Meet the project energy goals including 30% energy reduction as compared to ASHRAE 90.1-2004

Best lifecycle cost

Provide a world class healthcare mechanical system

Through a comprehensive analysis of the factors above and the UFC and RFP requirements, it was found that the optimum and most lifecycle cost-effective mechanical system for the new CRDAMCR hospital uses a multiple, parallel 100% Dedicated Outside Air System (DOAS) approach with a remote central plant that provides steam, heating hot water and chilled water to the facility.

6.1.1 Central Plant

The main chilled water, steam, hot water, and plumbing systems are centrally located in a remote Central Utility Plant (CUP) approximately 250' southwest of the Hospital loading dock. The CUP houses the following major equipment and its components: chillers, cooling towers, steam boilers, chilled water and condenser water pumps, hot water generators and distribution pumps, condensate return pumps, steam deaerators, chemical water treatment equipment, fire pumps, domestic water heaters, and booster pumps. The CUP is connected to the hospital campus via an accessible underground tunnel that terminates in a dedicated plumbing service room in the basement level of the hospital building. Further details of the systems located in the CUP are covered in Section 6.4.1.

6.1.2 Hospital/Clinic

A significant feature for a healthcare mechanical system is the ability to deliver and maintain the required amount of outdoor air while meeting the RFP energy reduction goals. Conventional re-circulating (mixed air) systems typically fail to provide or maintain the required amount of outdoor air (ventilation) to the occupied space. This issue is further compounded when incorporating variable air volume systems to reduce energy consumption. As a result, the conventional re-circulating air system does not effectively achieve both the indoor air quality and energy reduction goals required for this project. Although the advent of alternative systems has improved the performance and complexity of these recirculating systems, the fundamental challenge of providing and maintaining the UFC required outside air to the occupied space while reducing energy still remains difficult to accomplish in a lifecycle cost effective manner. To overcome the limitations of a conventional re-circulating system the CRDAMCR design incorporates a 100% DOAS. The DOAS utilizes 100% outside air and continuously exceeds the ventilation requirements of all occupied space (a stated goal of the RFP). This system provides superior indoor air quality and building flexibility, and when combined with the appropriately selected energy recovery devices exceeds the energy reduction goals specified for this project. Details of the 100% DOAS system and components can be found in Section 6.4.2.


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6.2 Performance Criteria

6.2.1 Intent

The intent of this Performance Criteria section is to collect in one place all the relevant information governing the design of the HVAC systems as a reference. The information is mainly gathered from the RFP, and from subsequent RFI responses, but where the RFP did not give specific information, assumptions have been made following good engineering practice. It is not the intent of this document to override the RFP and/or the RFI process.

6.2.2 Codes and Standards

The engineering calculations are based on the applicable Unified Facilities Criteria (UFC), the latest recommendations of ASHRAE, and good engineering practices consistent with industry practice. The UFC is the governing design/code guide for the project. If a conflict exists between UFC 3-600-01 and any other DOD document, referenced code, standard or publication, UFC 3-600-01 takes precedence. Where the various elements of the RFP are in conflict, the following priority list is used to establish precedence, in descending order, unless specifically noted otherwise:

UFC 4-510-01

RFP sections 01 10 00 Statement of Work and 01 33 16 Design After Award

Fort Worth District Architect Engineer Instruction Manual

RFP Specific UFGS Specifications and Project Criteria

Fort Hood Installation Standards

The military standards applicable to the design are as follows:

UFC 3-400-01 Design Energy Conservation

UFC 3-410-01FA Heating, Ventilating and Air Conditioning

UFC 3-600-01, Fire Protection engineering for Facilities

UFC 4-010-01, DoD Minimum Antiterrorism Standards for Buildings

UFC 4-510-01 Medical Military Facilities

The codes applicable to the design are as follows:

2006 International Building Code (IBC)

2006 International Mechanical Code (IMC)

2006 International Plumbing Code (IPC)

2006 International Fire Code (IPC)

2006 International Energy Conservation Code (IECC)

Energy Policy Act of 2005

The current versions at date of RFP of: National Fire Protection Association (NFPA); 30 – Flammable and Combustible Liquids Code; 37 - Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines; 54 – National Fuel Gas Code, 90a – Installation of Air Conditioning and Ventilating Systems, 96 – Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations, 99 - Standard for Health Care Facilities; 101 – Life Safety Code.

The standards applicable to the design are as follows:


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American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) handbooks; 2006 Refrigeration, 2007 HVAC Applications, 2008 HVAC Systems & Equipment, 2009 Fundamentals

ASHRAE Standard 90.1-2007 Energy Standard for Buildings except Low-Rise Residential Buildings.

ASHRAE Standard 62.1-2007 Ventilation for Acceptable Indoor Air Quality.

ASHRAE Standard 55-2004 Thermal Environmental Conditions for Human Occupancy

ASHRAE Guideline 1-1996 The HVAC Commissioning Process

ASHRAE 15-2007 Safety Standard for Refrigeration Systems

ASHRAE 170-2008 Ventilation of Health Care Facilities

ASHRAE 0-2005 Total Building Commissioning

NEBB Procedural Standards for Testing Adjusting and Balancing

Sheet Metal and Air Conditioning Contractors National Association (SMACNA)

USGBC - LEED v2.2

USP-797- Pharmaceutical Compounding – Sterile Preparations – Applicable to PHIV3 Room Codes

6.2.3 Outdoor Design Parameters

The following parameters are be used for the HVAC system:

Altitude (above sea level) 1,024 ft

Latitude 31.07 N

Longitude 97.83 W

Location Fort Hood, TX (WMO# 722576)

Outside temperature and humidity conditions (ASHRAE Fundamentals 2009):

6.2.3.1 Outside Design Conditions Summer

Dry bulb and coincident wet bulb (0.4% column) 99.9°F DB, 73.4°F WB

Wet bulb and CDB - 100% OA Coils (0.4% column) 81.0°F DB, 76.6°F WB

Wet bulb for evaporative heat rejection (0.4% column) 77.7°F WB

Enthalpy and coincident dry bulb (0.4% column) 41.9 Btuh/lb, 89.7°F DB

6.2.3.2 Outside Design Conditions Winter

Dry bulb and humidity ratio (0.4% column) 23.7°F at 9.4 gr/lb

6.2.4 Building Envelope Construction

6.2.4.1 Proposed Building

6.2.4.1.1 'U’ Values (Btu/hr-ft²-°F)

Roof Assembly 0.03 (R-33.3 equivalent)

Wall Assembly 0.068 (R-14.7 equivalent)

Glass Assembly 0.29 (R-3.4 equivalent)

6.2.4.1.2 Fenestration Performance

Glass Solar Heat Gain Coefficient (SHGC) 0.24

Equivalent Shading Coefficient (SC = SHGC/0.87) 0.28


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6.2.4.2 ASHRAE 90.1-2007 Baseline Compliant Building (for Baseline Energy Model)

6.2.4.2.1 ‘U’ Values (Btu/hr-ft²-°F)

Roof Assembly 0.048 (R-20.8 equivalent)

Wall Assembly 0.151 (R-6.6 equivalent)

Glass Assembly 0.75 (R-1.3 equivalent)

6.2.4.2.2 Fenestration Performance

Glass Solar Heat Gain Coefficient (SHGC) 0.25

Equivalent Shading Coefficient (SC = SHGC/0.87) 0.29

6.2.5 Indoor Design Criteria

The following parameters are used for the calculations that govern the HVAC system design.

UFC 4-510-01, Design: Medical Military Facilities and associated Appendix are followed for all applicable room temperature, humidity, air change rate, ventilation, and acoustic design criteria. For any non-standard rooms that are not covered by UFC 4-510-01, good standard engineering practice is applied for determination of the room design criteria. When ASHRAE 62.1 ventilation rates are in excess of UFC 4-510-01, the more stringent of the two is followed.

For space cooling calculations the space equipment heat loads are based on the actual quantities and locations of equipment for all rooms including: medical related rooms (as prescribed in UFC 4-510-01), electrical, telecom, kitchen, etc. Loads are based on actual equipment cut sheets when available. When cut sheets are not available, heat loads are determined using good engineering practice.

Lighting heat load information is be based on the actual lighting design for each space. HVAC calculations are performed assuming that day lighting controls are not in use.

Occupant densities are based on estimates indicated in the program for design project criteria or as listed in IMC-2006 or ASHRAE 62.1-2007 when other information is not provided. Associated sensible and latent occupant loads are based on expected personnel activity rates as listed in ASHRAE Fundamentals 2009.

6.3 System Design Standards

6.3.1 Airside

Equipment and terminal units are sized using the following criteria: Service Maximum velocity (FPM)

Relief or exhaust air louvers (Free area) 700 fpm

Outside air intake louvers (Free area) 500 fpm

Filters (AHU or duct mounted) 500 fpm

Heating coils 800 fpm

Cooling coils 500 fpm

Low wall return grille 400-600 fpm


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HVAC ductwork is sized using the following velocity criteria: System Maximum velocity (FPM)

Grease duct exhaust (Per mechanical code) 2,000 fpm (Min: 500 fpm)

Fume hood exhaust mains and risers 2,200 fpm

Variable volume supply air mains and risers 2,200 fpm

Constant volume supply air mains and risers 2,000 fpm

General exhaust mains 2,000 fpm

Low wall return duct 900 fpm

HVAC ductwork is sized using the following friction loss criteria: System Maximum Friction loss

Fume hood exhaust mains and risers 0.15 inch wc/100 ft

Variable volume supply air mains and risers 0.25 inch wc/100 ft

Constant volume supply air mains and risers 0.25 inch wc/100 ft

General exhaust mains 0.15 inch wc/100 ft

General exhaust sub mains and run outs 0.10 inch wc/100 ft

Transfer ducts 0.10 inch wc/100 ft

Supply air duct downstream of VAV or CAV terminal 0.10 inch wc/100 ft

(Note: Sizing criteria listed above is intended to be maximum values for system design. Lower values are used as needed to help meet the project energy goals.)

6.3.2 Hydronic

Hydronic piping is sized using the following criteria: Pipe size Maximum Pressure Maximum Flow rate (inch) Velocity (FPS) Drop (ft/100 ft) (GPM) ¾” 3.3 7.1 5 1” 3.1 4.6 8 1-½” 4.1 5.5 23 2” 4.8 5.0 50 2-½” 6.0 5.8 90 3” 6.1 4.5 140 4” 8.1 5.5 320 5” 8.8 5.0 550 6” 10.0 5.1 900 8” 10.0 3.8 1,560 10” 10.0 2.8 2,450 12” 10.0 2.3 3,540 14” 10.0 2.0 4,300 16” 10.0 1.8 5,700 18” 10.0 1.6 7,300 20” 10.0 1.4 9,100 24” 10.0 1.1 13,200 30” 10.0 0.9 20,940


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Notes on Pipe Sizing Tables:

Friction rates are based on: copper tubing sizes 3/4” – 2”, Schedule 40 new steel pipe for sizes 2½” and up. (Note: actual installed steel piping is Standard Weight, therefore pipe sizing table above is conservative.)

Sizing criteria listed above is intended to be maximum values for system design. Lower values are used as needed to help meet the project energy goals.)

6.3.3 Steam

Steam piping is sized using the following criteria: Low Pressure steam (less than 15 psig)

Maximum pipe velocity 4,000 fpm

Maximum pipe friction loss 0.5 psig/100ft

Maximum total system friction loss 3 psig

Medium Pressure steam (15 – 60 psig)




High Pressure steam (61 – 125 psig)




Steam condensate piping is sized using the following criteria: Pumped steam condensate

1” – 1-1/2” pipe size 2 fps max.velocity

2” – 3” pipe size 3 fps max. velocity

4” – 10” pipe size 4 fps max. velocity

High/Medium pressure steam condensate return

3/4” – 2” pipe size 1000 fpm flash steam velocity

Gravity steam condensate (2% slope)

1” pipe size 1,350 pph max. flow rate

1-1/4” pipe size 2,490 pph max. flow rate






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6.4 HVAC System Description

6.4.1 CUP

The project utilizes a remote central plant to house the major mechanical, electrical and plumbing equipment. The remote plant was selected to segregate noisy and frequently maintained equipment from patients and staff. A walk-able utility tunnel connects the central plant with the main facility and enters the hospital in a central location to reduce energy loss associated with utility distribution. The CUP building and associated piping systems are designed to accommodate a future chiller, boiler, cooling tower and associated equipment without building expansion or disruption of the existing systems. In addition, the building contains ample space for the maintenance personnel to monitor, operate, and maintain the mechanical and electrical systems for the facility. The CUP was located to maximize the distance between the cooling towers and boilers from the critical hospital HVAC systems while still meeting the architectural and civil needs of the site. The closest boiler flue exhaust is over 350' away from the closest Clinic outside air intake and over 500' away from the main Level 3 Hospital outside air intake to insure maximum dilution and provide excellent IAQ. The closest cooling tower is 475' and 550' away respectively. The hospital critical care outdoor air intakes are Northeast of the CUP providing additional safety against the southern prevailing wind for the Killeen area of Texas.

6.4.1.1 Chilled Water System

The central chilled water plant consists of (4) electric 1,305 Ton centrifugal, water-cooled chillers(0.35 kW/Ton NPLV) (includes one standby) piped in parallel with a 268 Ton modular heat recovery chiller(HRC) (6.0 total COP) providing an initial installed plant capacity of 5,488 Tons for an estimated total cooling load of ~3,800 Tons. The plant is sized to meet the full cooling load of the CUP, Clinics, and Hospital and has safety factor built in to accommodate an enthalpy wheel being down for maintenance in each system. Each of the centrifugal chillers is provided with a variable frequency drive (VFD) to provide optimum part load performance and the full system is piped in a variable primary configuration to further enhance efficiency. The heat recovery chiller is sized to carry the base winter cooling loads and each central chiller has the ability to operate under low load condition in the event the heat recovery chiller is down for maintenance. Sizing the heat recovery chiller to handle the minimum winter time loads allows the centrifugal chillers, cooling towers, and condenser water pumps to be turned off during those times. The system is designed to supply chilled water at 44F with return water at 60.6F. Plant floor space has been provided for an equally sized future chiller and blind flanges with isolation valves have been provided to facilitate future tie in. Each chiller has been provided with marine water boxes on the evaporator and condenser barrel to ease maintenance and cleaning.

6.4.1.1.1 Chilled Water System Pumping and Distribution

The chilled water pumping system consists of (4) vertical inline pumps (includes one standby) arranged in a variable primary pumping scheme. Vertical inline pumps were chosen to drastically reduce pump borne vibration while providing a compact space layout that facilitates maintenance needs. The pumping scheme has both the pumps and the chillers connected by a common supply and return header that allow any pump to run with any chiller to provide a higher level of redundancy. The HRC is provided in a side stream arrangement with (2) vertical inline pumps (includes one standby) to pump from the main


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return line, through the HRC, and then back to the main chilled water return line to pre-cool the return water before it reaches the main bank of centrifugal chillers. Plant floor space has been provided for an equally sized future chilled water pump and blind flanges with isolation valves have been provided to facilitate future tie in to the existing system. A life cycle cost analysis was used to optimally size the common pipe headers to allow future growth of an equally sized chiller while still meeting the project energy goals, limiting first costs, and meeting industry standard pipe sizing criteria. A side stream combination air/dirt separator, expansion tanks, system relief valves, and chemical feeder are provided in accordance with good design practice and are sized to meet the project needs. System flow meters have been provided to allow energy efficient control strategies, system diagnostics, and to provide real time building load data. A minimum flow bypass line with control valve is provided to protect the pumps and meet chiller minimum flow requirements during low demand operation. The major consumer of chilled water is the 100% DOAS chilled water air handling units (AHUs) located in the penthouses of the Clinics and patient Bed Tower as well as the main Level 3 mechanical room in the Hospital. The remaining consumers of the chilled water include fan coil units that provide space cooling for electric and telecom rooms and the radiant floor system used to cool the Concourse, Lobby, and Dining areas. Refer to later sections for more details on these systems.

6.4.1.1.2 Chilled Water System Piping Seismic Design

This project is categorized as Seismic Design Category A. Because of this category all chilled water system components are exempt from seismic analysis per ASCE 7-05 Chapter 13.

6.4.1.1.3 Chilled Water System Mission Critical Provisions

To handle the mission critical needs of the facility as prescribed by the UFC, (2) main chillers (one to standby) and (2) main chilled water pumps (one to standby) are backed up by the emergency generator. All necessary control panels and Energy Management and Control System (EMCS) systems are provided with UPS back up power in addition to the emergency generator to provide continuity of service during power shifting.

6.4.1.1.4 Chilled Water System Basis of Operation

The following sections are meant to give a brief overview of the planned operational approach for these key systems. Refer to the full sequence of operations included in the DP-3 submission drawing package for complete detail.

6.4.1.1.4.1 Centrifugal Chillers

Chiller is enabled based on building demand and starts after its isolation valves are proven open and condenser water and chilled water pumps are proven running.

Additional chillers are staged on/off by the EMCS. Staging is based on system cooling load demand and current chiller loading.

Chillers use internal logic to control to a set leaving water temperature of 44F.

A low flow bypass line is provided to maintain minimum flow requirements through the chillers at all times.

6.4.1.1.4.2 Heat Recovery Chiller


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Chiller is be enabled based on building demand and starts after its isolation valves are proven open and its associated circulation evaporator and condenser pumps are proven running.

Chiller is set to cooling mode and can be demand limited to maintain a minimum load on the steam boiler and/or centrifugal chiller as required.

The internal chiller control panel stages on/off module sections as required to meet demand.

A dedicated circulation pump on the evaporator and condenser side maintains a constant flow through the chiller.

6.4.1.1.4.3 Chilled Water Pumps

Lead chilled water pump is enabled to run 24/7 and initially starts after a chiller isolation valve is proven to be open.

Pumps are staged on/off based on system flowrate.

Active pump VFDs receive a common signal from the EMCS to maintain minimum differential pressure setpoints at multiple sensors throughout the piping system.

Pumps are lead/lag operated based on run time.

6.4.1.2 Condenser Water System

The condenser water system consists of (4) dual cell factory packaged, counterflow cooling towers (includes one standby) located at grade to the South of the CUP building. The towers are sized to meet the heat rejection of the centrifugal chiller plant and are provided with VFDs for energy efficiency at part load conditions. The system is designed for a supply temperature of 84F and a return temperature of 97F. Temperatures were selected using an energy model in concert with the chilled water system to provide optimum overall plant efficiency. The cooling towers are housed on a concrete basin which continuously drains to a concrete sump pit directly below the CUP floor slab so no equalizer or integral basins are required. Each tower is provided with an access ladder with associated platform for maintenance. Additionally, a steel service platform is provided between each pair of towers to provide additional access. The concrete basin improves system longevity, reduces maintenance, and provides better cold weather/shutdown protection by allowing all tower water to drain to the concrete sump pit when the towers are inactive. The basin system is shrouded from to keep out excessive unwanted rain, sunlight, and debris from the basin. The condenser water sump pit is split into two sections to allow annual cleaning in one section while the other section remains online. Each section is provided with access hatch and permanent ladder for any maintenance needs. The concrete sump has been sized to allow expansion of the tower system to include an additional tower of equal size. Condenser water treatment is provided by (2) chemical free magnetic pulse system chambers installed on the two main condenser water pipes serving the cooling towers. The system is designed to save water and eliminate the use of chemicals. Water savings is first accomplished by allowing higher cycles of concentration to be run in the condenser water loop than a conventional chemical system. Secondly, the absence of chemicals in the water allows the blowdown water to be harvested and used for site irrigation, saving valuable potable water. Each chiller has been provided with marine water boxes on the condenser barrel to ease maintenance and cleaning.

6.4.1.2.1 Condenser Water System Pumping and Distribution


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The condenser water pumping system consists of (4) vertical turbine condenser water pumps (includes one standby). The condenser water pumps are floor mounted on the slab directly above a concrete sump which stores the condenser water during operation and for winter time non-operational drain back. The pumps, chillers, and cooling towers served by a common supply and return header that allow any pump to run with any chiller or cooling tower to provide a higher level of redundancy. A life cycle cost analysis was used to optimally size the common pipe headers to allow future growth of an equally sized chiller, pump, and cooling tower while still meeting the project energy goals, limiting first costs, and meeting industry standard pipe sizing criteria. Isolation valves and blind flanges have been provided at the chiller and condenser water pump headers to ease future expansion; the cooling tower header in the tower yard is provided with a blind flange only. A centrifugal solid separator is provided to remove excess suspended solids in the water that are a part of the normal operation of the chemical free water treatment system. The separator has been provided in conjunction with sump sweeper piping to keep the chemical free system particulate waterborne such that it can be more effectively removed from the system.

6.4.1.2.2 Condenser Water System Piping Seismic Design

This project is categorized as Seismic Design Category A. Because of this category all condenser water system components are exempt from seismic analysis per ASCE 7-05 Chapter 13.

6.4.1.2.3 Condenser Water System Mission Critical Provisions

To handle the mission critical needs of the facility as prescribed by the UFC, (2) cooling towers (includes standby), (2) condenser water pumps (includes standby), the chemical free condenser water treatment system, and associated solid separator and sump sweeper systems are backed up by the emergency generator. All necessary control panels and EMCS systems are provided with UPS back up power in addition to the emergency generator.

6.4.1.2.4 Condenser Water System Basis of Operation

The following sections are meant to give a brief overview of the planned operational approach for these key systems. Refer to the full sequence of operations included in the specifications for complete detail.

6.4.1.2.4.1 Condenser Water Pumps

Condenser water pumps are enabled when there is a call for a chiller to come online and start once the chiller and cooling tower isolation valves are proven open.

Pumps are staged on/off based on the number of chillers operating.

Active pump VFDs receive a common signal from the EMCS to maintain design flow through the chillers.

Pumps are be lead/lag operated based on run time.

6.4.1.2.4.2 Cooling Towers

Cooling towers are enabled when there is a call for a chiller to run.

Towers are staged based on the number of chillers in operation.

Tower fans are enabled when the isolation valve for the associated tower is proven open and the leaving water temperature is above setpoint.


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Active tower fan VFDs receive a common signal from the EMCS to maintain leaving water setpoint as measured by a sensor downstream of the condenser water pumps.

Tower inlet valves close and tower bypass valve opens to divert water directly to the concrete sump pit when tower leaving water is below setpoint during low ambient temperature conditions. The reverse occurs once leaving tower water temperature rises to setpoint.

A leaving tower water temperature setpoint reset schedule is provided for condenser relief to maximize energy efficiency.

Cooling towers are be lead/lag operated based on run time.

6.4.1.2.4.3 Condenser Water Treatment

The Pulse Pure chemical free water treatment system is enabled whenever a condenser water pump is enabled.

The Pulse Pure system monitors the condenser water conductivity and open the blow down valve as required to maintain target cycles of concentration. The blowdown water is harvested and sent to the site irrigation tank to use for landscaping irrigation. If the irrigation tank is full, the EMCS alternatively dumps the blowdown into the sanitary system.

The main condenser water pumps continuously circulate flow through the solid separator located directly behind the pumps. The filtered water then pumps down into each sump pit and connect to a sweeper piping system to flush particulate back towards the main system pumps. A signal from the EMCS routinely opens a blowdown valve on the solid separator to discharge to sanitary. This small amount of blowdown is not suitable for irrigation, as it contains high amounts of suspended solids.

6.4.1.3 Steam Boiler System

The primary heating system consists of (4) dual-fuel forced draft high pressure steam boilers (includes one standby) that are sized to meet the heating hot water, process steam, humidification and domestic hot water loads for the medical center. Space for a future steam boiler of similar size and capacity is included within the boiler room. The primary steam header, deaerator, boiler feedwater system, surge tank and blowdown separator unit are also sized to accommodate the future boiler addition. Each steam boiler is 350 boiler horse-power (bHP) for a total initial installed plant capacity of 46,865 MMBH of steam (1,400 bHP) at 100 psig for a total estimated design load of 35,150 MMBH. The size of the heating plant was established through detailed load calculations that are available in the calculations design binder submitted under separate cover. Each fire tube boiler includes unit mounted controls, low NOx burner, and stack economizer to achieve the 85% minimum boiler efficiency required in the RFP. The boiler room is designed with concrete trenches to house the blowdown piping. Fuel oil, natural gas, and other related boiler trim piping is routed overhead. This feature improves access and maintainability of the boilers for the maintenance personnel. In addition, a steel catwalk is provided above the boilers to provide access to the stack economizers and isolation gate valves.

6.4.1.3.1 Steam Distribution System

High pressure steam is routed from each boiler to a common header located inside the boiler room. The majority of the steam is then routed towards a pressure reducing station that provides 40 psi steam for the heat exchangers that produce the heating hot water and domestic hot water for the facility. The remaining steam is routed to a separate pressure


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reducing station also located in the boiler plant. The resulting 90 psi steam is routed through the utility tunnel to the main facility where it is distributed and further reduced in pressure for use with the clean steam humidification system, kitchen equipment, and central sterile equipment. To improve the energy performance and reduce operating costs, steam condensate is collected from the main facility and returned to the central plant for reuse. Pipe sloping, drip legs, steam traps, and system isolation valves are provided in compliance with industry standards to insure proper system operation and maintenance.

6.4.1.3.2 Steam Distribution Seismic Design

This project is categorized as Seismic Design Category A. Because of this category all mechanical steam system components are exempt from seismic analysis per ASCE 7-05 Chapter 13.

6.4.1.3.3 Steam System Piping Thermal Expansion Design

Steam system piping has been analyzed for thermal expansion control. Calculations are provided to indicate necessary control features required to maintain piping system within ASME B31.9 maximum allowable stresses. Piping anchors, guides, expansion loops, and other control features are indicated on plan drawings and dimensional details are provided as dictated by calculations.

6.4.1.3.4 Steam Boiler System Mission Critical Provisions

Two boilers (one to run, one to standby) are provided with emergency generator power along with their associated support equipment to meet the mission critical needs of the facility. In addition each boiler is dual fuel and is capable of running off of natural gas or #2 fuel oil. A piped portable canister for standby propane pilot ignition system facilitates the ignition of the #2 fuel source when natural gas is not available. All EMCS control panels are provided with UPS backed up power to provide reliable transition between normal and emergency modes.

6.4.1.3.5 Steam Boiler Basis of Operation


6.4.1.3.5.1 Boiler Operation

Upon a call for steam, one of the central boilers and all associated steam equipment enables.

There is a plant master control panel that lead/lags boilers and interface with the individual boiler control panels, deaerator, surge tank, and EMCS.

Each Steam Boiler has individual burner safety and capacity control panels and control to maintain plant steam pressure setpoint.

Additional boilers are enabled by the plant master control panel to meet system demand and maintain plant steam pressure setpoint.

Primary fuel source is natural gas (NG), in the event of a loss of NG, the secondary fuel source is (#2 fuel oil) is enabled. See section 6.4.1.5 for fuel oil system.

6.4.1.3.5.2 Surge Tank Operation


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The condensate surge tank is sized for approximately 10 min system storage, to allow for steady feedwater system control. The surge tank and deaerator have been provided as a combination duo tank unit.

Transfer pumps are packaged with the surge tank, and enable to maintain water level within the deaerator.

6.4.1.3.5.3 Deaerator Operation

The deaerator tank is sized for approximately 10 min system storage, to allow for steady feedwater system control.

Low pressure steam is used to deaerate the low pressure condensate and makeup water to the tank.

The level controller sends signal to allow transfer pumps to enable, and a makeup water control valve modulates to maintain water level setpoint.

Feed water pumps are packaged with the deaerator, and enable whenever a boiler is enabled.

Feed water control valves at each boiler modulates to maintain water level within the boiler.

6.4.1.4 Heating Hot Water System

The heating hot water system is located in the central plant boiler room and is comprised of (3) steam-to-heating hot water heat exchangers (includes one standby). Space for a future heat exchanger of similar size and capacity is included within the boiler room. The heating hot water system was specifically evaluated and chosen to remain in the central plant (rather than distributed in the medical center) to integrate the heating hot water system with other heat recovery features, to centralize the operation and maintenance of the heating system equipment, and to optimize the use of the mechanical space for the facility. The heart of the heating hot water system is the steam-to-heating hot water heat exchangers that are each sized for 60% of the building heating load capacity. The heating hot water system is designed at a maximum supply temperature of 140°F supply to integrate with the heat recovery chillers, for the possible future integration of a solar hot water heating system (solar-ready), and to provide good controllability by the system control valves.

6.4.1.4.1 Heating Hot Water System Pumping and Distribution

The heating hot water pumping system is comprised of (3) vertical inline pumps (includes one standby) in a variable primary arrangement. Each pump is sized for 60% of the system flow and is provided with a VFD for part load energy efficiency. The heating hot water piping is routed to the main hospital and clinics via the walk-able utility tunnel. The pumps and heat exchangers are served by a common supply and return header that allows any pump to run with any heat exchanger to provide a higher level of redundancy. A life cycle cost analysis was used to optimally size the common pipe headers to allow future growth of an equally sized heat exchanger and pump while still meeting the project energy goals, limiting first costs, and meeting industry standard pipe sizing criteria. Isolation valves and blind flanges have been provided to facilitate such a future expansion. The major consumers of the heating hot water are the reheat coils for the constant volume terminal boxes that serve the majority of the hospital/clinic occupied spaces and the radiant floor heating that serves the main Concourse, Lobby, and Dining areas. Each of the


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custom air handling units (AHUs) are provided with a preheat coil, but they are not used in normal operation as the energy recovery wheels meet the preheating demands (refer to 6.4.2.6). The heating hot water system utilizes standard 2-way heating control valves along with industry standard coil connection specialties (refer to drawings and specifications for more details). Upon return to the CUP a portion of the hot water return water is diverted from the main return line to the HRC system. The HRC system has (2) vertical inline pumps (includes one standby) to pump water from the main return hot water line through the heat recovery chiller and back to the main return line in a side stream arrangement to preheat the return water before it passes through the main heating hot water heat exchangers. In route to the HRC the hot water flows through a 3-way valve where it can be diverted to a water to water double wall shell and tube heat exchanger to preheat the domestic hot water for the facility if the demand is present. The HRC is designed to heat the water up from 110F to 140F while providing 268 Tons of chilled water cooling capacity on the evaporator side. By decreasing the demand on the heating hot water and domestic hot water steam heat exchangers, load is shed from the steam boiler system providing considerable energy savings due to the ability of the HRC to produce heat at a much higher COP than the steam boilers. System flow meters have been provided to allow energy efficient control strategies, system diagnostics, and for real time building loads. A line size dirt/air separator, expansion tanks, system relief valves, and chemical feeder are provided in accordance with good design practice and is sized to meet the project needs. A minimum flow bypass line with control valve is provided to protect the pumps during low demand operations.

6.4.1.4.2 Heating Hot Water System Piping Seismic Design

This project is categorized as Seismic Design Category A. Because of this category all heating hot water system components are exempt from seismic analysis per ASCE 7-05 Chapter 13.

6.4.1.4.3 Heating Hot Water System Piping Thermal Expansion Design

Heating Hot Water system piping has been analyzed for thermal expansion control for the CUP and tunnel portions of the project and deemed no additional provisions required. For the DP-5 package the heating hot water mains for the basement and the main riser to the bed tower penthouse have been analyzed to ensure the piping system is within ASME B31.9 maximum allowable stresses. The piping for these areas are fully coordinated in the fabrication models to ensure accurate modeling in the stress analysis software. Piping anchors, guides, expansion loops, and other control features are indicated on plan drawings.

6.4.1.4.4 Heating Hot Water System Mission Critical Provisions

(2) Heating hot water pumps (includes one standby) are provided on the emergency generator. One pump is capable of meeting the mission critical loads of the facility as defined by UFC 4-510-01. All EMCS control panels are provided with UPS backed up power to provide reliable transition between normal and emergency modes.

6.4.1.4.5 Heating Hot Water System Basis of Operation


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6.4.1.4.5.1 Steam to Hot Water Heat Exchangers

All steam to hot water heat exchanger are enabled to run 24/7.

Steam temperature control valves are provided in a 1/3, 1/3, 1/3 load arrangement and modulate in sequence to maintain leaving heating hot water temperature setpoint.

6.4.1.4.5.2 Heating Hot Water Pumps

Lead heating hot water pumps are enabled to run 24/7 and initially start after steam to hot water isolation valve is proven to be open.

Pumps are staged on/off based on system flowrate.

Active pump VFDs receive a common signal from the EMCS to maintain minimum differential pressure setpoints at multiple sensors throughout the piping system.

Pumps are lead/lag operated based on run time.

A low flow bypass valve is provided to maintain minimum flow through the hot water pumps. If a hot water pump is at minimum speed and the system differential pressure is above setpoint the control valve modulates to maintain setpoint. If the differential setpoint drops below setpoint the valve modulates fully closed before the pump VFD rises from its minimum.

6.4.1.5 Fuel Oil System

The onsite fuel oil system provides #2 fuel oil to the emergency generators and boilers as prescribed in UFC-4-510 and RFP. The entire fuel system is contained within the CUP area of the facility. The fuel storage consists of (2) 35,000 gal underground double wall storage tanks and dedicated day tanks for each generator and one for the boiler plant. Each main tank is equipped with (2) submersible fuel pumps (includes one standby) that provide redundancy and eliminate the potential operational issues associated with below atmospheric suction piping. The main tank pumps supply fuel to the day tanks upon a call for fuel as indicated by float controllers mounted in each day tank. The boiler system has an additional duplex pump set that provides a constant pressurized fuel supply loop to the boiler plant when the plant is operating on the secondary fuel source. The fuel oil piping is constructed of UL listed buried double wall flexible piping below grade and transitions to welded steel once inside the CUP. Each day tank is double wall construction and provided with a return/overflow system that energizes a return pump that will pump down the day tank once the level indicator reaches 95% fill. The fuel will be returned to the main tank that is currently active for supply pumping. Leak detection alarms are provided for the secondary containment of each dedicated day tank; the interstitial space of the main below grade fuel tanks; in each connection sump of the main fuel oil tanks; in each pipe transition sump; and in the bottom of the skid for the boiler supply and return pumps. A dedicated gravity flow surface mounted remote fill port is provided for each below grade tank and located outside of the CUP fuel yard in proximity to Railhead Drive to the South of the campus. A truck pull off area is provided with a spill containment sump in compliance with EPA CFR 112. System is provided with audible and visual overfill alarms along with a


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mechanical overfill prevention valve to prevent overfilling the main tanks. The remote fill control panel has the ability to display of current fuel levels. A fuel oil polishing system is provided to filter out any water or contaminants from each of the main fuel tanks. Controls are provided to cycle through each of the tanks for an adjustable amount of time. System controls include a tank selection software system that manages the sequencing of all pumps and motorized valves for the supply and return system. Fuel oil leakage alarms, pump failure alarms, critical low and critical high fuel level alarms are all available locally to the control package and are available to the EMCS system as well. Additionally a fuel oil inventory system is provided that can provide reports on the current fuel storage levels.

6.4.1.5.1 Fuel Oil System Piping Seismic Design

This project is categorized as Seismic Design Category A. Because of this category all fuel oil components are exempt from seismic analysis per ASCE 7-05 Chapter 13.

6.4.1.5.2 Fuel Oil System Mission Critical Provisions

The entire fuel oil system is backed up by the emergency generator system to allow full operational capabilities in case of a mission critical event.

6.4.1.6 CUP HVAC Systems

6.4.1.6.1 Chiller Room

The chiller room is located in the CUP and is heated and cooled via (2) horizontal blower coil units hung from the structure above. The blower coils are sized to handle the heat gain of the non-hermetic York chiller motors. The room is continuously exhausted via a roof mounted exhaust fan to meet ventilation requirements. Outside air is drawn in from a fixed open louver to the outdoors. In the event of a refrigerant leak a refrigerant detection system has been provided which will increase the room exhaust to be in compliance with ASHRAE 15.

6.4.1.6.2 Boiler Room

The boiler room is cooled and ventilated via (2) roof mounted exhaust fans and fixed open louvers to provide make up air. The intake louvers are sized per NFPA requirements for boiler combustion air make up with one louver residing within 1' of the floor slab and the other 1' from the roof structure. During winter operation the boiler combustion air is tempered by (2) horizontal hot water unit heaters mounted at the louver intakes. Hot water unit heaters are also provided as required within the room to supplement the radiated heat from the steam boilers. Motorized dampers are not provided for the boiler combustion air make up louvers due to the mission critical nature of the room. Failure of actuators or end switches to operate correctly could compromise the ability of the boilers to operate causing a dangerous situation for the facility.

6.4.1.6.3 Generator Rooms

Each generator room is provided with fixed open louvers sized to make up the generator radiator and combustion air requirements. Summer ventilation is provided via a roof


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mounted exhaust fan in each generator room controlled by room temperature. A hot water unit heater is provided for each generator room and is sized to maintain the room at 55F when the generators are not in operation. Motorized dampers are not provided for the louvers due to the mission critical nature of the room. Failure of actuators or end switches to operate correctly could compromise the ability of the generators to operate causing a dangerous situation for the facility. Gravity backdraft dampers are provided to help limit infiltration while providing a failsafe pathway for the generator combustion and radiator cooling airflows.

6.4.1.6.4 Main Elect Rooms

The main electric rooms within the CUP are heated (where required) and cooled via blower coil units with hot and chilled water coils. Ventilation is provided to each room as required by ASHRAE 62.1 via a dedicated constant air valve served from P-AHU-1. The ventilation air also serves to provide slight positive pressure relative to the outdoors.

6.4.1.6.5 Medium Voltage Switchgear Room with battery storage

One of the medium voltage switchgear rooms contains battery storage for UPS and is provided with space conditioning, as well as code compliant ventilation provided by P-AHU-1. The exhaust fan is interlocked with the charging equipment as required by the UFC.

6.4.1.6.6 CUP Program For Design Spaces

A vertical, chilled water, variable air volume (VAV) AHU with terminal reheat boxes are provided to heat and cool the office spaces within the CUP. The system is provided with minimum outside air, with no heat recovery, and has fully ducted returns. A roof mounted exhaust fan is provided for toilet rooms, janitor closets, etc. as required to meet UFC general exhaust guidelines and/or good industry practice. The hazardous materials room and paint prep room are held at a negative pressure relative to its surroundings and provided with dedicated exhaust fans.

6.4.2 Hospital/Clinic Building HVAC Systems

6.4.2.1 Hospital/Clinic General Spaces Supply Air System

The RFP required that an AHU be limited to a smoke zone or a department boundary, whichever was smaller. As a result, there was a high quantity of units that would have been required varying significantly in capacity. Each unit then would have had to be individually ducted to the applicable zone. This would have resulted in a system that was not ideal in regards to life cycle costs, serviceability, maintainability, and redundancy. The design build team developed an alternative approach that provides enhancements in each of these categories. In addition, it meets or exceeds all of the code requirements in regards to the life safety of the occupants. Life safety is paramount in this facility, and should not be compromised. The proposed system uses smoke dampers to isolate smoke zones in lieu of dedicated AHU’s per zone. This meets the intent of all applicable code provisions, and provides the user with a simple, robust means of reacting to incidents within a smoke zone. The proposed system is much less complicated, easier to install and operate, and provides benefits to the owner for the life of the facility. A complete white paper titled “Air Handling


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Unit Configuration” has been submitted in response to RFI #79 that goes into depth the advantages of the alternative system provided. The proposed mechanical system is a 100% DOAS with custom chilled water air handling units with duct zoning that provides the capability to isolate each department. The system provides the following benefits to CRDAMCR:

Improves indoor air quality by continuously exceeding the minimum outside air ventilation standards required by the UFC and ASHRAE.

Mitigates risk associated with airborne infection by providing 100% outside air and eliminating recirculation of air.

Maximizes system flexibility for future renovations with the capability to achieve all UFC or ASHRAE ventilation requirements for any space type without modifications.

Exceeds the minimum USGBC energy savings and contributes to LEED Gold Certification.

Exceeds the EPACT 2005 energy saving goal of 30% lower than ASHRAE Standard 90.1-2004 in a lifecycle cost-effective manner

Achieves the 2007 Energy Independence and Security Act (EISA 2007) energy savings goal lower than the database for similar projects in a lifecycle cost effective manner.

Incorporates the Integrated Building Systems (IBS) design intent by utilizing identical custom air handling units throughout the project with a headered ductwork arrangement that allows for equipment redundancy and ease of maintenance

Provides accessible and logical distribution network throughout the interstitial zone to meet the IBS intent.

The hospital and clinic mechanical systems utilize outside air pre-conditioning sections that recover the energy of the building exhaust air to pre-condition the outside air. These outside air pre-conditioning sections are located in mechanical penthouses at the roof of the clinics and patient bed tower, and in the main third floor mechanical room of the hospital, adjacent to the air handling units. Energy recovery is achieved through the use of enthalpy wheels with proven long term performance, minimal maintenance, and consistent reliability. As added value to the Government and a commitment to the quality of this product, a 10-year full service manufacturer’s warranty for the enthalpy wheels has been provided. After passing through the enthalpy wheels, the pre-conditioned outside air continues into identical 45,000 cfm custom chilled water air-handlers manufactured by Temtrol. For each mechanical room several air handlers are grouped together to feed a common duct header that then route out of the mechanical room to serve each occupied smoke zone. The headered arrangement allows for multiple levels of redundancy. Each central air handling unit has an array of 9 supply fan cells, where 8 are active and one is standby. This redundancy allows for an air handling unit to maintain system airflow even in the event of a fan failure or maintenance outage. Secondly if an entire unit were to go off line for maintenance, the other units can ramp up to help support it to allow all zones to remain occupied until maintenance is complete. After leaving the associated mechanical room, the ducting proceeds through the IBS level to feed each of the building's smoke zones. The duct layout is arranged such that a single smoke damper (or pair for some zones to enhance the duct layout) can be closed to isolate a given smoke zone from other smoke zones served by the same system. All ductwork is sealed to SMACNA seal class A standards and is constructed with spiral where space permits with the remaining ductwork constructed rectangular.


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Constant volume terminal hot water reheat boxes located in the IBS level are provided for the final distribution into the occupied spaces. These boxes are located at chest level in the IBS for ease of maintenance and have rigid ducting downstream that penetrates the IBS floor slab down into the connection zone. Fire stopping is provided for each duct penetration through the IBS slab. Flex duct is provided in the connection zone to make the final attachment to ceiling mounted supply diffusers. General building humidification is accomplished with injection of chemical free steam at the central air handling units, and is designed to maintain 30% RH for the building. Additional trim humidifiers are provided for NYIC1 and NYIR1 spaces as required to meet room design criteria in UFC 4-510-01, Appendix A. Outside air intakes are located in compliance with both healthcare criteria and with Anti-Terrorism criteria. Intakes for the main hospital building are located on the 3rd floor and Bedtower Penthouse level. OA intakes for the Clinic buildings are located on the 2nd and 3rd floor Penthouse levels.

6.4.2.2 General Exhaust Air System

The general exhaust system for the facility is integral to the 100% DOAS system described above. Each space is provided with exhaust grilles with ductwork that extends up through the connection zone into the distribution zone. Once in the distribution zone, the exhaust air is collected in sub-branch ducts then headered together in an exhaust main that serves each smoke zone. At the boundary of each smoke zone a smoke damper is provided to isolate the smoke zone. To control the exhaust volume for each smoke zone the smoke damper is provided with modulation capability to exhaust the design airflow volume as indicated by a duct mounted airflow measuring station. By controlling exhaust airflow down to the smoke zone level the facility has the ability to make easier future modifications to space airflows to meet future needs without having to rebalance the entire system. Downstream of the smoke damper the exhaust main is then tied in with other exhaust mains from other smoke zones and is routed back to its associated mechanical room. Once to the mechanical room all the system exhaust is pulled through the enthalpy wheels to reclaim the valuable energy to precondition the incoming outside air. The motive force for the exhaust system is provided by large vane axial exhaust fans mounted within custom housings. The housings are custom built for each mechanical room and are built with double wall insulated panels for rigidity and acoustic attenuation. The fans pull the air through the entire exhaust system and then discharges the air first through a bank of silencers then out through exhaust louvers located in each penthouse and the main level 3 mechanical room. Dedicated exhaust systems such as isolation rooms, isolation anterooms, cylinder storage rooms, hazardous materials rooms, the morgue, sterilizer hoods, cart washers, dryers, prosthetics/lamination shops, radiology hot labs, nuclear medicine decay storage and injection rooms, decontamination shower, the dental prosthodontics lab, and anterooms exhaust is provided with dedicated exhaust systems per the UFC and be exhausted directly to the outdoors without passing through the enthalpy wheels. General building exhaust air outlets are located to exceed code minimum separation from building outside air intakes. General


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6.4.2.3 General Supply and Exhaust Smoke Damper Operation

Each smoke zone within the facility has the ability to be isolated via duct mounted smoke dampers or in some cases a combination fire smoke damper. These dampers are fail closed and are primarily controlled by the EMCS with dampers in the supply being two position and the dampers in the exhaust being modulating to maintain constant exhaust air volumes. The fire alarm system has a relay wired in series with the EMCS power wiring allowing it to break the power connection when commanded by the fire alarm system causing the damper to close. The associated duct smoke detectors are wired back to the fire alarm system such that if a detector in the supply or exhaust senses smoke then the fire alarm system closes all the associated supply and exhaust smoke dampers for a given smoke zone. As an added provision the fire alarm system is programed to provide a manual flush mode of a given smoke zone that allows the smoke detector to be overridden off for an adjustable time frame and allow smoke to be flushed from a space after an event. This provision is not required by code and is solely provided as an additional capability.

6.4.2.4 System Air Balancing

All medical spaces served by the 100% DOAS units are balanced to meet the UFC guidelines for pressurization. Positive and negative rooms are hard balanced with an appropriate airflow offset between the constant volume supply and exhaust provided to the space. The offset provided is determined via calculation based on the details of the door provided for a given space. Neutral rooms have the supply and exhaust volumes match one another. Corridors are hard balanced to provide a positive offset to maintain an overall positive pressure in each building with respect to the outdoors. An overall positive building pressure helps save energy by limiting unwanted humidity and air infiltration. Similar to the other medical spaces, the isolation rooms are hard balanced with an offset between the constant volume supply and exhaust provided to the room. The offset are based on a calculated pressure drop based on the door characteristics. The pressure differential between the room and adjacent corridor or anteroom are monitored to ensure safety to the patients and hospital staff. Refer to the associated sequences of operation and P&IDs for detailed information on pressure monitoring approach, ranges, and alarm points. Air Balance Tables are provided in the DP-5 calculations binder. Airflows and associated balances have been provided to coordinate with corridor door locations. Overall smoke zone pressurization is provided by applying an offset to the exhaust air flow station volume flow rate setpoint. See sequence of operation for more detail.

6.4.2.5 Enthalpy Wheels / Custom Housing

The heart of the 100% DOAS system is the custom enthalpy wheel housings where the energy exchange occurs between the incoming outside air and the outgoing exhaust air streams. These systems are located in each of the penthouses and the main level 3 mechanical room. While different in size for each mechanical room the concept is the same for each instance. Each housing is comprised of large enthalpy wheels mounted in the center of a housing made of double wall insulated panels. The housings are further split by a horizontal platform that separate the exhaust deck from the outside air deck. The lower level of the housing is the outside air deck. Outside air is pulled in through fixed exterior louvers and then passes through a MERV 9 pre-filter before passing through the rotating enthalpy wheels. After passing through the wheels, the air then flows through the opposite side of the housing directly into the back of the system AHUs for further


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conditioning before feeding the distribution ductwork. Access doors are provided for entry into both sides of the enthalpy wheels for maintenance. The upper level of the housing is the exhaust air deck. Exhaust air is pulled into the housing from the exhaust duct system in a counterflow direction opposite of the outside air below. The air passes through the enthalpy wheels and once on the opposite side is drawn into the neighboring exhaust fan housing for expulsion from the building. Access to the exhaust deck is provided via ladders from the outside air deck below.

6.4.2.6 100% DOAS Custom Air Handling Units

A major goal of the airside design is to provide a flexible system that minimizes maintenance complexity while providing system redundancy. To meet these goals each Temtrol custom air handling unit is of a typical size and configuration. In lieu of providing air handling data from two manufacturers, per Attachment H, Temtrol was determined to be the User’s preferred manufacturer at the design after award design charrettes. Each unit contains the following components:

Low leakage inlet isolation damper

Preheat coil

Humidifier section

Cooling coil with copper tubes and aluminum fins

UVGI lights

Access sections

Direct drive supply fans installed in a fan array (Fan Wall), N+1 arrangement.

Each supply fan is provided with an integral back draft damper

Supply fan inlet airflow measuring probes

Variable frequency drives

High capacity, high efficiency MERV 14final filters

Smoke rated discharge isolation damper

Appropriate air and coil appurtenances

Acoustic analysis indicated that unit mounted silencers are not required for the AHUs that are served by the south bank of enthalpy wheels in the Level 3 mechanical room as assumed during preliminary design. While the main focus of the fan arrays are to provide additional system level redundancy, a secondary benefit is the reduced overall sound power that fan arrays provide in comparison to a typical single or dual fan AHU. The lower sound power from these units helps mitigate downstream attenuation to help save energy. Refer to Mechanical Calculations binder for full acoustic analysis.

6.4.2.7 Operating Room System

The Operating Room (OR) system is comprised of (4) chilled water AHUs, with each AHU serving (2) ORs. The units are located in the main Level 3 mechanical room and are tied into the 100% outside air preconditioning system similar to the main hospital systems. The associated supply and exhaust ductwork to each OR is routed in the IBS space above the ORs. Each OR is provided with a variable volume terminal box with reheat capability so that each OR is its own independent zone. The terminal boxes are programmed to run at a constant volume for occupied or unoccupied airflow. Final filters are provided for all supply diffusers in the ORs and are diffuser mounted.


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The exhaust from each OR is collected via low wall exhaust grilles and is regulated by a pressure independent variable volume exhaust valve box for each OR allowing independent control. The supply and exhaust valves are programmed for an airflow offset to maintain a positive space pressure. Downstream of the exhaust valves the exhaust flow ties into (2) independent exhaust headers that route back to the north group of enthalpy wheel housings in the Level 3 mechanical room. The exhaust is routed through a dedicated enthalpy wheel, which is isolated from the main general exhaust system, for energy recovery. After exiting the enthalpy wheel housing the air is ducted to (2) dedicated inline mixed flow exhaust fans and is expelled from the building via wall louvers. Each fan is sized to handle (4) occupied and (4) unoccupied ORs to provide additional redundancy. Humidification is accomplished with injection of chemical free steam at each of the (4) operating room air handling units, and are designed to maintain 30% RH for the rooms. Each operating room is provided with a pressure monitoring system to ensure that each OR remains pressurized to the dirty corridor. Refer to the associated sequences of operation and P&IDs for detailed information on pressure monitoring approach, ranges, and alarm points.

6.4.2.7.1 Operating Room NFPA 99 Smoke Purge System

A smoke exhaust fan system has been provided for the OR suite for NFPA 99 compliance. The system is comprised of a single smoke rated fan located on the roof over the OR suite and exhaust duct routed to each OR with a dedicated control damper for each OR. If smoke is detected by a room area smoke detector then the smoke exhaust fan is energized and the associated control damper is opened by the EMCS and controlled to maintain the normally positively pressurized OR into a negatively pressurized space to prevent smoke from spreading out of the room into adjacent spaces. The supply and exhaust system transitions into unoccupied mode during this event.

6.4.2.7.2 Operating Room Emergency Air System Shutdown Operation

During an Emergency Air System Shutdown the UFC requires for Operating Rooms to continue to remain active. The OR suites continue to operate, but in a 100% re-circulation mode. In such an event the supply and exhaust terminal air valves for each OR are temporarily put into maintenance mode. Once shutdown the exhaust fans are de-energized and their associated isolation dampers close. At the same time the exhaust fans are de-energized the outside air dampers on the AHUs close while the emergency return dampers on the AHUs open. Once all dampers are proven in their new positions the temporary shutdown override is removed and ORs are allowed to go back into occupied mode in a staged manner.

6.4.2.8 C-Section Rooms

The C-Section room is served by a dedicated chilled water variable volume AHU with back up capability during maintenance events from the Lvl 3 central air handling system. Each C-Section room is provided with a variable volume terminal box with reheat capability so that each room is its own independent zone. The terminal boxes are programmed to run at a constant volume for occupied times and constant volume but at a reduced rate for unoccupied times. Final filters are provided for all supply diffusers in the C-Section rooms and are diffuser mounted. To meet the UFC the C-Section AHU has the capability to go into full recirculation mode during an ATFP event.


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The exhaust from each C-Section room is collected via low wall exhaust grilles and is regulated by a pressure independent variable volume exhaust valve box for each room allowing independent control. The supply and exhaust valves are programmed for an airflow offset to maintain a positive space pressure. Downstream of the exhaust valves the exhaust from each room is headered together and routes to a dedicated exhaust fan located in the Lvl 3 Mech Rm. For redundancy the exhaust can be temporarily routed to the Lvl3 North general exhaust system during times of fan maintenance.. Each C-Section room is provided with a pressure monitoring system to ensure that each OR remains pressurized to surrounding corridor. Refer to the associated sequences of operation and P&IDs for detailed information on pressure monitoring approach, ranges, and alarm points.

6.4.2.8.1 C-Section Room NFPA 99 Smoke Purge System

A smoke exhaust fan system has been provided for the C-Section room suite for NFPA 99 compliance. The system is comprised of a single smoke rated fan located on the roof over the labor and delivery area and exhaust duct routed to each C-Section room with a dedicated control damper for each room. If smoke is detected by a room area smoke detector then the smoke exhaust fan is energized and the associated control damper is opened by the EMCS and controlled to maintain the normally positively pressurized OR into a negatively pressurized space to prevent smoke from spreading out of the room into adjacent spaces. The supply and exhaust system transition into unoccupied mode during this event.

6.4.2.9 Pathology HVAC System

The pathology department is located on the North end of Level 2 of the main hospital and consists of offices, BSL-2 labs and support spaces, and a BSL-3 lab and support spaces. The entire pathology department is provided with supply air from the main 100% DOAS system located on in the Level 3 main mechanical room. The BSL-2 general lab and office spaces are provided with standard air terminal valves similar to the rest of the facility; with the exception that some BSL-2 labs with hood or equipment exhaust connections are provided with laboratory grade exhaust valves similar to the BSL-3 described next. The BSL-3 spaces are provided with quick response, low leakage type laboratory grade valves. Inherent redundancy is provided for the supply air system due to being fed from a main supply header consisting of (6) AHUS, all of which have fan arrays. Due to the close proximity of the department to its associated mechanical room the additional pressure drop of the laboratory grade air terminal valves are not be the driver in setting the duct static pressure setpoint to avoid penalizing the project energy goals. The exhaust system for the pathology department is three tiered. The offices and other clean support spaces have hard balanced exhaust air that is returned to the Level 3 mechanical room to pass through the main enthalpy wheels for energy recovery similar to other portions of the project. The BSL-2 labs and associated support spaces are provided with pressure independent constant volume systems with the use of standard grade exhaust terminals in rooms without hood or equipment connections and laboratory grade valves on any rooms with hood or equipment connections. Any UFC required pressure relationships are provided by providing an offset between the constant volume supply and exhaust provided for a given room. The offset is determined by calculating the pressure drop across the associated room doors based on the door characteristics. The general lab exhaust is routed through the IBS and then up to the roof above the pathology department and directly exhausted to the outdoors via (2) N+1 redundant exhaust fans sized at 100%


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duty with exhaust stacks to expel the air a minimum of 20' above the roof line. The BSL-3 lab areas are provided with quick response, low leakage type laboratory grade exhaust valves that track the supply valves to maintain the UFC mandated pressure relationships. The exhaust is then routed to the roof above the Pathology department, pass through (2) N+1 redundant (one standby) HEPA filter banks with associated (2) N+1 exhaust fans sized at 100% duty each before being discharged up and out of exhaust stacks at a minimum of 20' above the roof line. Exhaust connections to any Type II A2 hood, Type II B2 hood, grossing station, fume hood, or biological safety cabinet in the BSL-2 or BSL-3 is provided with laboratory grade exhaust valves as described above. The BSL-3 and portions of the BSL-2 system are provided with a pressure monitoring system to ensure that each space maintains its design pressurization Refer to the associated sequences of operation and P&IDs for detailed information on pressure monitoring approach, ranges, and alarm points. The BSL-2 and BSL-3 exhaust has been located such that it is located approximately 150 ft to the east from the closest outside air intake. Additionally being east of the closest outside air intake means that the north and south prevailing winds take the exhaust flow away from the building in both instances.

6.4.2.9.1 Pathology HVAC Emergency Air System Shutdown Operation

During an Emergency Air System Shutdown the UFC requires the outside air intakes to be closed. As a consequence the BSL-2/3 area systems shut down due to the lack of make-up air. During an event the EMCS safely shuts down the lab area so personnel can leave. The BSL-2/3 spaces will return to a neutral pressure during this mode of operation. The BSL-3 rooms have been designed to be tightly sealed by utilizing heavy duty door seals, door bottoms and industrial transfer valves to ensure that there is no reversal of airflow in BSL-3 space.

6.4.2.10 Lobby/Concourse/Dining Radiant Heating and Cooling System

The Lobby/Concourse/Dining areas of the CRDAMCR project are unique in nature with respect to the rest of the facility. The area serves as the main entry point into the hospital, a main pathway for occupants traveling between the clinic and hospital areas, as well as a main central dining area for the campus. The main north and south walls are heavily glazed with 30' ceilings. To provide world class comfort and help meet the project energy goals, a radiant heating and cooling system has been provided for the entire Lobby/Concourse/Dining area. Radiant heating and cooling is a great fit for high ceiling areas as it allows conditioning to be focused down at the occupied level while allowing the unoccupied high ceiling areas to stratify. During the summer months the cooled floor absorbs the direct radiant solar heat on the South facing glazing and irradiated sky solar radiation on the North facing glass. During the winter months the heated slab provides great occupant warmth while being very effective at combating cool drafts from the tall glazing. The radiant system is zoned into exterior and interior zones similar to a conventional airside HVAC system to match space usage and exterior loads. The radiant system is supplemented by the 100% outdoor air DOAS system that serves the hospital portion of the facility. This system doubles as providing ventilation air for the entire Lobby/Dining/Concourse area and also provides trim heating and cooling capacity to supplement the radiant system in high load areas such as the South facing glazing. The ventilation air is delivered to the space via variable air volume terminal boxes located in the surrounding IBS that serve wall air distribution grilles. The terminal boxes have a tiered


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operational sequence that includes temperature, carbon dioxide levels, and space humidity control. The primary control is to maintain space temperature, but the terminals have a setpoint offset to preferentially load the radiant floor. Secondly the volume is allowed to reset down based on space carbon dioxide levels when supplemental cooling is not required as a part of demand controlled ventilation system to save additional energy. The design allows modulation from the ASHRAE 62.1 minimum outside air rate down to the area based ventilation rate. Lastly, the supply volume can be reset upwards based on space humidity levels to ensure the dew point remains within UFC bounds and well below the slab floor temperature. A relief fan is provided in the ceiling plenum of the dining area and is modulated to maintain a positive pressure in the lobby area to limit infiltration.

6.4.2.11 Kitchen Exhaust System

The kitchen and servery for CRDAMCR is split between two floors with the main kitchen located in the Basement and the main servery area located on Level 1. The basement level also includes the pot wash and ware wash equipment that serves both levels. To help meet the aggressive energy conservation goals for the facility, an innovative variable exhaust system is used for the kitchen hoods over the heat and grease producing equipment. The system modulates the exhaust flow of the hoods with UL listed volume dampers based on an internal algorithm that takes into account exhaust temperature, exhaust particulate, and cooking surface temperature. By modulating the exhaust airflows to better match the actual usage, exhaust fan energy is saved year round for all partial cooking times. Additionally for further energy savings the make up air for the kitchen system is also set to track the exhaust volume to save both fan and cooling plant energy. The terminal boxes for the kitchen are allowed to modulate up from the UFC minimum air change rate to maintain space temperature or to make up the current hood exhaust volume. When the kitchen hoods are totally off the terminal boxes go to their UFC minimums and a general exhaust system exhausts the air to mitigate any odor spread from the kitchen area to other portions of the building. The terminal boxes for the servery modulate to maintain space temperature only. Because the servery is permanently open to the Dinning/Lobby/Concourse area, the remaining make up air for the hoods is transferred from that area. When the kitchen hoods are totally off the terminal boxes go to their UFC minimums and any excess air is relieved out of the building through the Lobby/Dining/Concourse relief air system. The moisture laden air from the ware wash and pot wash hood equipment is provided with independent constant volume systems and is enabled continuously to meet UFC air change requirements.

6.4.2.12 Electric / Telecommunication Rooms

6.4.2.12.1 Main Electric Rooms

The main hospital/clinic electric room located on Lvl 1 of the hospital is provided with 4-pipe chilled and hot water fan coil units that are installed above access aisles as required to meet access and NEC requirements. Fan coil units are sized to handle the envelope transmission loads in addition to the electrical equipment heat gains. To meet the mission critical provisions as required by the UFC, the fan coil units and associated controls are backed up with emergency generator power. Ventilation air is provided in compliance with ASHRAE guidelines via wall mounted supply grilles.


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6.4.2.12.2 Branch Electric Rooms

Branch electric rooms are provided with a cooling only chilled water fan coil unit that is installed above the door swing in each room. The associated chilled water piping drops into the room from the IBS above while the condensate piping is run within the wall cavity of a local wall near the unit down to an approved receptacle in the floor below. To meet the mission critical provisions as required by the UFC the fan coil units and associated controls for electric rooms serving mission critical areas are backed up with emergency generator power.

6.4.2.12.3 Main Telecom Rooms

The Main Communication Room (MCR), Main Telecommunication Room (MTR), and Telecom Head End Rm located in the basement level of the hospital are provided with chilled water computer room air handling units (CRAHs) located within the rooms. Each of the rooms has been provided with an allotment of 60 W/ft², 60 W/ft² , and 30 W/ft² respectively to handle the current equipment provided by the DB team and the future equipment to be provided by the government. The telecom cabinets and associated cooling system design are arranged in a hot/cold aisle arrangement. The UFC prescribed temperature of 68F is maintained in the cold aisle that feeds the inlet of server equipment as recommended by ASHRAE Applications Chapter 19; temperatures in the hot aisles may be in excess of 68F and dependent on actual telecom equipment loads. Room dehumidification and humidification is provided from the main hospital 100% DOAS system via wall mounted supply air grilles. The CRAH is not provided with integral humidifiers or have reheat capability which saves energy and reduce maintenance costs. To meet the mission critical provisions as required by the UFC the CRAHs and associated controls are backed up with emergency generator power. A redundant standby CRAH unit is provided for each room as required by the RFP.

6.4.2.12.4 Branch Telecom Rooms

Branch telecom rooms are provided with a cooling only chilled water fan coil unit that are installed above the door swing in each room. The associated chilled water piping drops into the room from the IBS above while the condensate piping is run within the wall cavity of a local wall near the unit down to an approved receptacle in the floor below. To meet the mission critical provisions as required by the UFC the fan coil units and associated controls for electric rooms serving mission critical areas are backed up with emergency generator power. Room dehumidification and humidification is provided from the main hospital 100% DOAS system via wall mounted supply air grilles.

6.4.2.13 Life Safety Systems

6.4.2.13.1 Lobby Smoke Control System

The main entry Lobby, Dining area, and Concourse portion of the facility is considered a two-story atrium, interconnecting the Floor 1 and Floor 2 of the Hospital and is required to have a smoke control system per NFPA 92B and 101. To provide the required smoke exhaust, (7) exhaust fans are provided at the top of the atrium and are to be activated by the fire alarm control system from a signal from either smoke detector or sprinkler flow switch. The design intent is for smoke to be pulled from these spaces in a fashion such that fresh air is drawn in from entry doors with automatic openers commanded by the fire alarm system in the opposite direction of egress so the fresh air can keep the egress pathways clear while meeting the NFPA requirement of maintaining the smoke level 6' minimum above the highest level of exit. The exhaust fans are UL listed for use in a smoke


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exhaust system and is located above the ceiling and accessible via a catwalk from the local IBS zone. The reflected ceiling plan of the entry Lobby, Dining area, and Concourse is designed to provide the necessary free area for smoke from the occupied areas to be pulled vertically into the ceiling plenum where it is drawn over to the intakes of the exhaust fans and expelled out of the building through dedicated louvered penthouses on the lobby roof in proximity to the fans below. The calculations for required exhaust volumes and further detail on life safety systems can be found in the associated narrative.

6.4.2.13.2 Stairwell Pressurization System

Exit stairs 02, 03, and 04 in the hospital are over 75 ft in height and, therefore, require stair pressurization meeting NFPA 101. Each high-rise hospital stair has an independent pressurization fan system. Stair 03 and 04 has roof mounted utility set fans that feed a duct riser that is routed inside of each stairwell behind a chase wall to deliver pressurization air at multiple vertical points within the stairwell. Stair 02 offsets horizontally on Levels 3 and 4 of the hospital, so to better serve this condition (1) fan is located on the roof of Lvl 6 to feed the upper floors while (1) additional fan is located on the roof of Lvl 3 to feed the lower floors. The Stair 02 fans have direct injection into the stairwell and do not have a ducted riser. Each stairwell is provided with barometric relief venting to maintain appropriate pressurization levels. Further detail on life safety systems can be found in the associated narrative.

6.4.2.13.3 IBS Manual Purge Exhaust System

UFC 4-510-01 - Section 12-14.5.3 requires a means for purging the distribution zone (IBS level) of smoke and other products of combustion for post fire operations. The system has to be manually enabled and have the ability to be remote controlled from the fire emergency control center. The system is comprised with normally closed constant air volume terminal boxes with an associated low leakage isolation damper on the supply air system on one side of a given IBS area. On the opposite side of a given IBS zone area, normally closed low leakage isolation dampers are installed on some of the ends of the typical exhaust branch ducts. When the manual purge cycle is initiated the supply terminal boxes open and provide metered 100% outside air from the DOAS system directly into the IBS zone. The air then flush the smoke across the IBS zone and be exhausted by the main exhaust system.

6.4.2.13.4 Patient Sleeping Room Smoke Control

Zoned smoke control is provided throughout smoke compartments with patient sleeping rooms, in accordance with Section 12-14.5 of UFC 4-510-01. The design approach is to isolate the zone of incidence. If a smoke event is detected in the associated areas the supply and exhaust smoke dampers are commanded closed by the fire alarm command system.

6.4.2.14 IBS Emergency Heating System

Low temperature maintenance of the IBS levels is provided by the terminal boxes associated with the IBS Manual Purge Exhaust System. A small volume of supply airflow is discharged into the IBS if at any time the IBS space reaches a low limit of 55F. Programming is provided to modulate the hot water heating valve to maintain a minimum temperature of 55F. Note that based on the winter design temperature, calculations indicate the IBS will naturally remain warmer than 55F from the heat gains through the IBS from the space below. Heating capability has been provided as an emergency back up measure for extreme winter conditions.


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6.4.2.15 Cooling Coil Condensate Collection System

To maximize the water usage efficiency of the facility a cooling coil condensate collection system has been provided. The system collects condensate from each of the main 100% OA DOAS units located in the penthouse of each clinic and the penthouse and level 3 mechanical room of the hospital. Condensate from each building is gravity drained to a receiver located on an associated lower floor and is then pumped back to the CUP where it is deposited into the cooling tower basin. This system diverts water from the sanitary and/or storm system and harvests it for use as make up water for the cooling towers.

6.4.2.16 Misc Systems

6.4.2.16.1 Stairwells

Stairwells with external exposures are provided with a floor mounted console type unit heater at the bottom of the riser. Stairwells that serve the roof additionally have a propeller type unit heater located at the top landing of the roof. Stairwells located on the interior of the building do not require heating.

6.4.2.16.2 Entry Vestibules

Main entry vestibules are provided with a heat only fan coil to combat any wind driven infiltration during the winter cooling season. The building is designed for a slight positive pressure to minimize infiltration for both the heating and cooling season and keep the vestibules cool during the summer.

6.4.2.16.3 Elevator Machine Rooms

Elevator machine rooms are conditioned with chilled water (and hot water when the room has an exterior wall) fan coil units. These units are located within the room and have power backed up by the emergency generator.

6.4.2.16.4 CUP Tunnel Ventilation

The CUP tunnel is ventilated with transfer air from the Plumbing/Med Gas room located in the hospital. Air is delivered to the Plumbing Room, passes through a fire damper into the tunnel, passes through the tunnel, and is exhausted through a fire/smoke damper at the CUP end and discharged up and out the building via a roof mounted exhaust fan.

6.4.2.16.5 Kitchen Water Cooled Compressors

Many of the major refrigeration systems within food service department are cooled via water cooled compressors. Many of the main compressors have been ganged together in a common rack with a central chilled water supply and return connection while others are single isolated ice makers. Each compressor has its own head pressure control valve that is provided integral with the kitchen equipment. The scope of the chilled water system is to provide chilled water with a minimum pressure differential of 20 psi between the supply and return connections. There are no control valves or EMCS tie in’s for this system.

6.4.3 Parking Garage HVAC Systems

The electrical equipment rooms and elevator machine rooms located in the Clinic, Hospital, and Staff Parking Garages are conditioned to maintain temperatures as required per electrical equipment manufacturer requirements with through the wall DX air-conditioning units. The units are wall-mounted on the exterior wall and ducted into the room. The units have self-contained controls that aren’t monitored by the BAS.


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6.4.4 Ambulance Garage HVAC Systems

The Ambulance Garage are provided conditioned air by a DX split system unit. The indoor unit is located in the mechanical/electrical closet within the shelter and ducted into the space. Outside air enters the unit through a louver on the south side of the shelter and feed into a mixing plenum with the return air. A relief damper and louver release excess air while maintaining a positive pressure in the shelter. The outdoor condensing unit is located on the west side of the shelter on an equipment pad. The condensate is sloped to the west side of the building and terminated over a splash block. The four roll-up garage doors are provided air curtains (“air doors”) to reduce infiltration/exfiltration as required by the UFC. The air curtains are provided with stand-alone controls based on the door position and aren’t monitored by the BAS. The DX AHU and condensing unit are provided with stand-alone controls and aren’t monitored by the BAS. Recommended room set point, 80°F (ADJ) during normal operation minimizes energy waste when garage doors are open. HVAC system designed to condition space to 78°F during mass casualty usage mode. There is no RFP requirement for vehicle exhaust removal system. The ambulance shelter design assumes that the Ambulances do not idle inside the ambulance shelter rather they are parked in the area.

6.4.5 Building Automatic Temperature Control Systems

Per the RFP, the Energy Management and Control System (EMCS) serving the existing hospital is a dedicated TAC Invensys system that provides HVAC controls and monitoring for existing main hospital building and for over twelve other medical facilities throughout the base. A complete EMCS suitable for control and monitoring of the HVAC systems and other building level system is provided for the Replacement Hospital Building and for the Central Utility Plant (CUP) Building. The head end workstations are provided in the CUP control room, basement security office and level 6 Emergency Operations Center. The existing remote clinic systems remain in operation to support building’ current tenants and has the capability to be monitored by the Replacement Hospital EMCS. Additional detailed information regarding the system architecture is provided in the controls sub-contractor shop drawings. Information regarding the HVAC system operation approach and functionality can be found in the HM8-XXX series drawings in the form of sequences of operation, P&IDs, and F&IDs.

6.4.6 Heat Load and Airflow Calculation Process

The supply and exhaust airflows for the entire hospital, bed tower, and three clinic buildings were calculated using a combination of design tools. These calculations are all formatted in an excel file to clearly communicate how the design team reached the final supply and exhaust flows.

6.4.6.1 Model Extraction

An extraction from the Revit model produces a database of all the rooms and spaces in the model with their corresponding equipment and JSN numbers. Other information extracted includes room area in square feet, department name, UFC room code, unique room identifier, and floor reference.


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6.4.6.2 Shell Loads

TRACE version 6.2.6.5 was utilized to model all the exterior exposure types in the building. All aspects of the building were modeled including shading, various types of glass and walls, and all of the unique exposure orientations. Room by room take-offs were completed to get an accurate representation of wall and window square footages for each room. These square footages were used in conjunction with the TRACE model outputs to calculate a total heat gain for each space from the building skin.

6.4.6.3 Internal Loads

The load calculation process accounts for the following internal space loads:

Equipment Load: The Revit Model extraction process allows for every piece of heat generating equipment in the building to be associated with a specific room. Utilizing the MILST1691 document in conjunction with ASHRAE standards and the UFC code allows for an accurate equipment load calculation to be completed for each room in the building.

Lighting Load: Information provided by the electrical contractor and UFC minimum requirements for each space are utilized and compared to calculate the heat gain from lighting.

Occupant Load: A room by room evaluation is used to determine the number of occupants for each space to ensure that a proper sensible and latent heat gain is applied to each space.

6.4.6.4 Airflow Calculation and Comparison

Four separate airflow calculations were performed for each space to ensure that the proper supply and exhaust airflows were applied.

Sensible Cooling Airflow: This calculation utilizes the UFC required temperatures for each space along with the equipment load, shell load, and all other internal loads to calculate the airflow required for cooling.

Sensible Heating Airflow: This calculation utilizes the exposure data and the UFC required heating temperature to calculate the required airflow to heat the space with the integrated heating coil in each CAV box.

UFC Minimum Air Change Airflow: This calculation utilizes the UFC minimum air change rate specified in Appendix A along with the space data to calculate the airflow required to achieve the minimum number of air changes required.

ASHRAE Minimum OA Airflow: When applicable, ASHRAE standard 62.1-2007 Outdoor Airflow Rates are calculated to ensure that industry standard ventilation rates are being met.

The calculations described above are all compared and the highest calculated airflow is chosen to ensure that all space requirements are met. Microsoft Excel was chosen for the final output as it allows for formatting that clearly displays the driving factors for each room airflow in a layout that is easy to review.

6.4.7 Integrated Building System (IBS) design

The approach to the IBS design is described in a separate narrative section titled “Basic IBS Design Concepts.”

121121 crdamc hvac design analysis

Documents

hvac system selection

hvac system description

overall hvac system

air system doas approach

condenser water pumps

system design standard

hot water generators

main chilled water