health care ventilation and … lead other health care design stakeholders to consider more...
TRANSCRIPT
Presenters
Bob Rutkowski, PEVice President Health Care Designvan Zelm Engineers
Steve Krawczynski, PEPresidentvan Zelm Engineers
NEHES 2012 FALL CONFERENCE, SPRINGFIELD, MA
HEALTH CARE VENTILATION
AND
RADIANT/INDUCTION COOLING
…Challenges and Opportunities of introducing
Sustainable Practices into Health Care Design
[CT Children’s Medical Center]
October 3, 2012
Learning Objectives
1. Participants will be able to assess and select an appropriate HVAC system approach for different health care occupancies using the criteria presented to evaluate if radiant and/or induction space cooling is suitable.
2. Following the progressive steps demonstrated, participants will be able to effectively communicate and lead other health care design stakeholders to consider more efficient and effective HVAC strategies.
Traditional Health Care
Design
HEALTH CARE DESIGN
• Culture Driven by Regulatory Requirements
• Prescriptive Environmental and Safety Requirements
• Engrained into the DNA of Hospital Operations
NON-COMPLIANCE is Extremely Serious !
Risk of Hospital Doors Being Closed
HOSPITAL HVAC DESIGN 101
Conservative – Conservative - Conservative
Ventilation Requirements Dictate:System SelectionEquipment Space NeedsSize of Distribution Systems (ducts)
Internal Gains vary by Space Type:Most Handled by High Ventilation Rates
Minimal Consideration of:Envelope PerformanceInvestment in Conservation
Users, Clinicians, Facilities Staff are:Expecting Traditional Approaches
PATIENT ROOM HVAC HISTORICAL APPROACH
Local H & C Terminals with Exhaust-Fan Coils Units-Induction Units
All Air Based Systems-Constant Volume-VAV with Reheat (usually electric)
Mixed Bag-Dual Duct-High Pressure Induction Units-Radiant Ceilings (with rain ☺)
1960’s – 70’s
1980’s – 90’s
Current Standard
HISTORY OF HOSPITAL DESIGN REGULATIONS
The Hill-Burton Act was used to fund the development of US Hospitals in the wake of the World War II.
The Original “General Standards” appeared in the “Federal Register” as part of implementing the Hill-Burton Act.
1947
[Hartford Hospital]
Criteria and Parameters were left largely to the discretion of the design community.
1950-60’s
HISTORY OF HOSPITAL DESIGN REGULATIONS
Publication of:“Minimum Requirements of Construction and
Equipment for Hospital and Medical Facilities”
AIA Publication of:“Guidelines for the Design and Construction of Hospital and Health Care Facilities”
AIA Guide Evolved into the:“FGI Guidelines “– 2010 Current Edition(Facility Guidelines Institute)
1974
1987
+/- 2000
REFERENCED VENTILATION STANDARD
ANSI/ASHRAE/ASHE - Standard 170“Ventilation of Health Care Facilities”
• Prescriptive Criteria by Space Type:
• Relative Pressure to Adjacent Spaces
• Minimum Outdoor Air• Minimum Total Air Delivery• Recirculation Allowed/Not• Exhaust Requirements• In Room Recirculation Units
Allowed/Not• Design Temperature & Humidity
• Addenda Published in 2011
Published 2008
Standard 170 is Referenced From the FGI.
Traditional Health Care
DesignSustainable Design
Principles
Specific Metrics as Project GoalsEnergy ConsumptionCarbon EmissionsRenewable Energy Quality of Indoor Environment
Test Perceptions & Traditional NormsEngage StakeholdersComfort Criteria Options
Drive Thermal Loads DownReduce Equipment SizeEnabling ThresholdsAlternative System Selections
Take a Holistic ViewpointFind Synergies and Trade OffsEvaluate Alternatives
Conservation and Environmental ImpactValued in Decision Process
INTEGRATED DESIGN APPROACH
Minimize load as a first priority.
Select low energy delivery systems that are cost‐ effective
Produce and Distribute energy
efficiently
Operate the building well
Building Design and Program fixes
the load
Primary Energy Systems provided for aggregate of loads
Building Systems needed to meet
the load
People run the systems
A Series of Integrated Steps
DELIVERING HIGH PERFORMANCE BUILDINGS
CREATIVE CHALLENGES
“We want the Student to SEE the Heat Wheel in Operation”
Ideas in Motion
Heat Wheel
BASICS OF ENERGY DISTRIBUTION
To transport 100,000 Btu / hr:
30”
16”
Supply Return
Air Based Hydronic Based
1 ½”
CHWS CHWR
Fan Horsepower: 4.2 hp
Annual Electric Cost $2711
Pump Horsepower: 0.3 hp
Annual Electric Cost $193
16”
30”
LOW ENERGY HVAC SYSTEM APPROACH
100% OA
DOAS Unit W/ Energy Recovery
Exhaust
Supply
Cool/Dry Supply Air
Hot / Chilled Water Supply
Room / Zone
ReturnChilled Beam
or Radiant
Ventilation Control
Temperature Control
DOAS SYSTEM BASICS
BulletsMinimum air – just to meet ventilation requirements and remove latent heat from spaceLook at MVR Presentation
NON – CONDENSING COOLING SYSTEMS
Example 1 - New Academic Biology Lab Building
Combined General and Fume Hood Exhaust
Enthalpy Heat Wheel used on laboratory exhaust.(One of first to use this technology in Region)
Elimination of Perimeter Heating System
Effect of Dilution
First LEED Gold Research Lab Building in US
Worcester, MA
Satisfy EH&S Concerns
Envelope / Glazing Performance Upgrade
Example 2 - New Academic Office / Classroom Building
Detailed Envelope Performance Criteria Established
Low Energy HVAC Delivery Systems
Glazing Balance Between Daylighting, Solar Gain and Views
Over 1,000 sf/ton Cooling Demand
Chilled Beams Radiant Cooling
DOAS Ventilation System87% Effective Heat Recovery
Cambridge, MA
Collaborative Atmosphere Between Owner & Design Team
Air transfer makeup for kitchen
hood exhaust
Triple glazed with high performance framing
system
In‐Floor radiant heating and cooling
Chilled Beams above wood slat
ceiling
Architectural / Mechanical Collaboration
Main Gallery
Traditional Health Care
DesignSustainable Design
Principles
Compliance Challenges
Opportunities
HEALTH CARE REGULATIONS ARE EVOLVING
ASHRAE Standard 170Addenda a thru h
(Published 2011)
Recirculation of air on central systems:-Allowed for spaces that previously required 100% Exhaust.-Note: recirculation is required to have HEPA filtration
Recirculation in-room without filtration-Allowed if unit is non-condensing-Enables the use of cooling induction units (Chilled Beams)
This is huge step towards discussing more progressive and low energy HVAC systems within the boundaries of
regulatory requirements
STANDARDS CONTINUE TO EVOLVE
Pending - ASHE/CMS Revisions
Reduction in Minimum Humidity Criteria From
35% to 20%
Recent Study Estimates:
Save $200 Million in Energy Cost in the USover a 10 Year Period
SIGNIFICANT CHALLENGES IN HVAC DESIGN
Space to place larger equipment and Ductwork
Fixed envelope loads
Tight project schedules
Relocating Program Locations
Existing systems not suitable
Capacity Issues
Central plant
Distribution
Impact remote to area of renovation
$’s to upgrade infrastructure often not available / accounted for
Renovations
SIGNIFICANT CHALLENGES IN HVAC DESIGN
Need for new or expanded infrastructure Capacity
Large part of overall project cost
Cost constraints limit options
Envelope upgrades seldom pursued
Architectural goals and MEP needs are often at odds
Equipment
Distribution
New Construction / Major Expansion
Traditional Health Care
DesignSustainable Design
Principles
Compliance Challenges
OpportunitiesConceptual approach
PATIENT ROOMS
• Ventilation Rates are Constant
• 24 x 7 patient room occupancy – huge opportunity for savings with efficient ventilation system
• Space temperature management is reacting to a relatively constant internal gain
• Minimal Equipment Loads• Occupants are Relatively Sedentary
• Envelope - every patient room has an exterior window –opportunity for load reduction
OPPORTUNITIES
Separate ventilation from space
temperature control
OPPORTUNITIES
PUBLIC / ADMINISTRATION / CIRCULATION
• Loads are comparable to Academic and Commercial Facilities
• Lower ventilation loads
• Internal gain and envelope dominate• Large portion of Cooling Load is sensible
• IAQ less regulated
Incorporate ideas from high performance
buildings in non-health care applications
CURRENT APPROACH - ALL AIR DELIVERY
Exhaust System
Usually Perimeter Heatand/or Reheat on VAV
Supply System
Return System
Patient Room
DOAS + ACTIVE CHILLED BEAM APPROACH
Exhaust System
Supply System
Chilled Beam
PipingPatient Room
Piping PackageACB
ACB – Piping Connections
SIMPLE PIPING
FULL PATIENT FLOOR USING CHILLED BEAMS
Supply Air Riser
PATIENT ROOM USING RADIANT PANELS
Radiant Panels
Ceiling Obstacles
•Patient Lifts•Curtain Tracks•Lighting•Sprinkler Heads•Speakers•Smoke Detectors•Access Panels
Traditional Health Care
DesignSustainable Design
Principles
Compliance Challenges
OpportunitiesConceptual approach
Metrics
HOSPITAL SPACE PROGRAM
Space Type % of Total Area
Example SF
Opportunityfor new
approach to HVAC
Non‐Invasive Clinical 15% 75,000
Invasive Clinical 15% 75,000
Patient Rooms 25% 125,00 X
Clinical Support 15% 75,000
Public / Circulation 10% 50,000 X
Administration 10% 50,000 X
Back of House (MEP, Storage, Etc) 10% 50,000
Example:500,000 SF Hospital Facility
Approximately 45% of Total Hospital Area are candidates for DOAS + Radiant or Induction Cooling.
TARGETED SPACES FOR NEW HVAC APPROACHES
Space Type 24/7 Operation
% Load Envelope
% Load Internal
% LoadVentilation
ApproximateSF / Ton
Patient Rooms Y 20% 20% 60% 350
Public / Circulation Y 35% 25% 30% 450
Administration N 30% 40% 30% 400
•DOAS Ventilation Systems
•Heavy fan HP savings
•Heat Recovery benefits
•Sensible Cooling Terminals•HP reduction moving from Air based Cooling
•Increased central plant efficiencies •Chiller Delta T•More Economizer Benefit
CONSERVATION OPPORTUNITY
EXISTING HOSPITALS:
Energy DOG’s250 - 350 kBTU/sf /yr
NEW HOSPITALS:
Around 200 kBTU/sf/yr
HIGH PERFORMANCE HOSPITALS:
Potential for 150 kBTU/sf/yr
This is REAL SAVINGS !
OTHER SPACES – CONSERVATION OPPORTUNITY
Space Type % of Total Area
Example SF
RecirculationOpportunity
Non‐Invasive Clinical 15% 75,000 X
Invasive Clinical 15% 75,000 X
Patient Rooms 25% 125,00
Clinical Support 15% 75,000 X
Public / Circulation 10% 50,000
Administration 10% 50,000
Back of House (MEP, Storage, Etc) 10% 50,000
Example:500,000 SF Hospital Facility
For Existing Hospital Facilities+/‐ 45% of total area is suitable
For Air System Retrofit forRecirculation with HEPA Filtration
Traditional Health Care
DesignSustainable Design
Principles
What to do NOW
Compliance Challenges
OpportunitiesConceptual approach
Metrics
HEALTHCARE DESIGN RESOURCES
Energy Star
Tool to Validate Actual Energy Conservation Performance
-Document Actual Energy Consumption-Establish Facility Baseline
-Meter and Sub-Meter-Know where energy is being used
-Retro-Commissioning-Identify Low-Hanging Fruit
-Commitment to Improve Annually-Set Goals-Build a Culture of Conservation
Run Around Coil
Heat Wheel
RETROFIT OPPORTUNITIES
Convert old Radiant / High Pressure Induction systems to
DOAS with Low Pressure Induction Units or ACB’s
Get more capacity from existing plant and distribution infrastructure
using high delta T systems.
ADD heat recovery
Convert 100% OA systems to recirculation with HEPA filtration
Demand control operation of ventilation systems based on:
TimeOccupancy
Procedure Scheduling
Reduce quantity of OA for existing recirculation systems per new standards
Reduce demand on existing plant and distribution
Save energy $’s
Traditional Health Care
DesignSustainable Design
Principles
Compliance Challenges
Opportunities
Sustainable Health Care
Design
Conceptual approach
What to do NOW
Metrics
MAKING THE CASE
Health Care System…is being asked to do more with less in an Increasingly Competitive Environment
Regulations… are Evolving and allowing for more Efficient Buildings and Systems
Efficiency…does NOT need to cost more or reduce Environmental Health and Safety
Reducing Environmental Impact… is good for the health of the Community
Sustainable Health Care Design…is GOOD Business !
Q & ABob Rutkowski, PEvan Zelm Engineers
Steve Krawczynski, PEvan Zelm Engineers