Innovative Air Distribution for Healthcare Facilities
Types of Healthcare Facilities
• Hospitals– Variety of spaces, each with different needs
– Operate continuously
• Nursing care facilities
• Surgery Suites
• Clinical Facilities
Operational Characteristics of a Hospital
Cooling10%
Refrigeration2%
Ventilation16%
Water Heating 12%
Office Equipment
1%
Computers3%
Miscellaneous8%
Cooking2%
Space Heating16%
Lighting30%
• Most areas operate continuously (24/7)
• Most spaces have perimeter exposures (wide load swings)
• HVAC costs represent about 45% of hospital utility costs
• Hospital utility costs are 40% higher than other buildings
Operational Characteristics of a Hospital
• HVAC service demand varies significantly– Cooling and heating loads vary
according to season
– Cooling loads significantly lower during night and evening hours
• System must be designed for maximum capacities– Exceeded less than 1% of the time
– Seattle (0.4%) design 85DB/65WB
– Portland design 90DB/67WB
Load includes Patient, Healthcare Team, Family, Equipment, and Solar
Operational Characteristics of a Hospital
Mixed Air Systems
Supply air at 600 fpm
Throw to 150 fpm
Throw to 50 fpm
Entrained air at 75 deg+
73 75 77
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Why Not Save Energy and Sound with Active Chilled Beams
55oF Primary Air
6,600 BTUH2,600 BTUH
Over Cooling!
Protective Isolation Room Pressurization
Patient Room (+)Hall (-)
Nursing Area HVAC Requirements
• Inpatient care units– Positive/neutral pressure vs. hallway
– Total airflow rate* of 4 to 6 ACH-1
– No stagnant areas
* Outdoor airflow rate must be at least 2 ACH-1
• Chilled beams– Constant air volume
• Consistent room air movement
• Guaranteed ventilation delivery
• Easy to maintain pressurization
– Quiet
– Minimal maintenance
Ceiling Based for Dilution Ventilation
Under Window Displacement Ventilation
Active Chilled Beams
Remainder of sensible load removed by chilled water,
(above the dew point)
Remainder of sensible load removed by chilled water,
(above the dew point)
Airflow requirement reduced by 2/3 or more
Airflow requirement reduced by 2/3 or more
Constant Air Volume OperationConstant Air Volume Operation
An Active Chilled Beam is just a Diffuser
An Active Chilled Beam is just a Diffuser
•Pressure relationship between room and hallway must be maintained.
• Air is only re-circulated within the room, (like a standard diffuser).
• Water in coil must be above dew point, a dry coil.
Active Chilled Beams
• Filtration normally required where room air is circulated through cooling coil
• OSHPOD will review on case by case basis to determine that the system can guarantee that the chilled water will be above the due point.
Chilled Beams with VFL Constant Volume Regulator
Active Chilled Beams typically require 0.4-0.6”w.g. S.P.
Energy Savings
Conventional Patient Room, 120 rooms ~
48,000 CFM @ 2” w.g. 24/7/365 = 32BHP @ 0.07$/KWH = $16,500/yr Operating Cost
Vs Active Chilled Beam Solution, 120 rooms ~
16,000 CFM @ 2” w.g. 24/7/365 = 9.8BHP @ 0.07$/KWH = $ 3,600/yr Operating Cost
Over 75% saving in Op. Cost Savings!!!
Sound Reduction
Conventional Patient Room ~
Terminal Unit @ 400 CFM; Rad. NC 21, Dis. NC 22, + Diffuser
Resulting in Room NC of 30
Vs Active Chilled Beam Solution, per room ~
Terminal Unit @ 100 CFM; Rad. NC <10, Dis. NC <10, + Chilled Beam
Resulting in Room NC of 25
Savings to Project
•Less Structure due to smaller Air Handler
•Smaller Shaft Sizes
•Smaller Duct Sizes
•Possible Shorter Building Height
•Possible Elimination of Terminal Units, (DOAS)
•Elimination of DDC Points
Infectious Isolation Room Pressurization
Patient Room (-)Hall (+)
Nursing Area HVAC Requirements
• Infectious isolation units – Negative pressure vs. adjoining spaces
– Total airflow rate* of 6 ACH-1
– All exhaust direct to outdoors
– Minimize stagnant areas
* Outdoor airflow rate must be at least 2 ACH-1
• Chilled beams– Constant air volume
• Consistent room air movement
• Guaranteed ventilation delivery
• Easy to maintain pressurization
– Quiet
– Minimal maintenance
Infectious Isolation Room Pressurization
Patient Room (-)Hall (+)
VFL
Volume Flow Regulator (-)
VFL
Volume Flow Regulator (+)
Exhaust
VFL
Volume Flow Regulator (+)
VFL
Volume Flow Regulator (-)
Nursing Area HVAC Requirements
• Infectious isolation units
• Protective isolation rooms – Positive pressure vs. adjoining spaces
– Total airflow rate* of 15 ACH-1
– All exhaust direct to outdoors
– No stagnant areas
* Outdoor airflow rate must be at least 2 ACH-1
Protective Isolation Room Pressurization
Patient Room (+)Hall (-)
VFL
Volume Flow Regulator (+)
VFL
Volume Flow Regulator (-)
Exhaust
VFL
Volume Flow Regulator (-)
VFL
Volume Flow Regulator (+)
TROX Clean Beam
• Face removes for stage 1 cleaning
• Entire coil can be removed if stage 2 cleaning required
• Can be furnished with lint filter
TROX Clean Beam
Stage 1 Cleaning
(No coil removal)
Stage 1 Cleaning
(No coil removal)
Stage 2 Cleaning
(Coil removed)
Stage 2 Cleaning
(Coil removed)
Air Distribution in Surgical Suites
• Contamination considerations– Clean air should “flood” operating area– No entrainment of unfiltered air
• Comfort considerations– High lighting and activity levels– Lower design temperatures
• Air distribution requirements– Low velocities in operating area – Minimize effects of obstacles in air stream
Supply Diffusers for Surgical Suites
• Procondif diffuser
• Honeycomb core
• Directional laminar discharge
• Operating table height– No room air entrainment
– Airstream width ≈ 6 feet
• Optional high efficiency filter
Supply Diffusers for Surgical Suites
ASHRAE STANDARD 170-2008
“Ventilation of Health Care Facilities”
Is Now PublishedIs Now Published
7.4.1 Surgery Rooms, Class B & C Operating Rooms
a. “Airflow shall be unidirectional, downwards…over the patient and surgical team”
Operational Characteristics of a Clinical Facility
• Occupied 12 to 16 hours daily– Cooling and/or heating loads vary
according to season
– Must be designed for peak loads which occur infrequently
• High risk of exposure to disease– Waiting areas
– Examination rooms
Displacement Terminals in Healthcare Facilities
Low Sidewall Mounted Diffusers
Quarter Round Diffuser
Displacement Terminals in Healthcare Facilities
Displacement Terminals in Examination Rooms
Displacement Chilled Beams in Patient Rooms
8-10”
Innovative Air Distribution for Healthcare Facilities