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

MIN

DESIGN

C.V. Terminal

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Flo

w(C

FM

)

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