Presentation on theme: "Innovative Air Distribution for Healthcare Facilities."— Presentation transcript:
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 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+
MIN DESIGN C.V. Terminal o o o Flow(CFM) Why Not Save Energy and Sound with Active Chilled Beams 55 o F Primary Air 6,600 BTUH 2,600 BTUH Over Cooling!
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) Airflow requirement reduced by 2/3 or more Constant Air Volume Operation
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.
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
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
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
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 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