Copyright Price Industries, Inc. 2012 1
Jerry Sipes, Ph.D., P.E.Vice President of Engineering
Displacement and Chilled Beams in Healthcare
Introduction – Health Care Ventilation Standards
Displacement1. Overview2. Theory and Design Considerations3. Patient Room Example
Chilled Beams1. Overview2. Theory and Design Considerations3. Patient Room Example
Outline
Copyright Price Industries, Inc. 2012 2
Emerging Health Care Design TrendsHealth Care Ventilation Standards
ASHRAEStandard 170 – 2008
AIA 2006(Adopted by 42 States)
AIA 2010(Includes ASHRAE 170)
Emerging Health Care Design TrendsHealth Care Ventilation Standards
Recently published ASHRAE 170 addendums:
• Addendum G – Further definition of Air Diffusers for Patient Rooms (Displacement)
• Addendum H – Further definition of Recirculating Room HVAC units (Chilled Beams)
Copyright Price Industries, Inc. 2012 3
Single bed patient rooms Group A, Group D, or Group E
All other patient care spaces
Group A or Group E
All other spaces No Requirement
ASHRAE standard 170
Emerging Health Care Design TrendsHealth Care Ventilation Standards
Table 7 – 1, Notes(s) For single bed patient rooms using Group D diffusers, a minimum of six total air changes per hour shall be provided and calculated based on the volume from finished floor to six feet above the floor 6’- 0”
ASHRAE standard 170, Addendum G
Emerging Health Care Design TrendsHealth Care Ventilation Standards
Copyright Price Industries, Inc. 2012 4
Emerging Health Care Design TrendsHealth Care Ventilation Standards
ASHRAE standard 170, Addendum H
Table 7 – 1, Notes(a) The portion of the ‘Minimum Total ach’ required for a space that is greater than the ‘Minimum Outdoor ach’ required component may be provided by recirculating room HVAC units. Such recirculating room HVAC units shall:
(1) Not receive non-filtered, non-conditioned outdoor air,(2) Serve only a single space,(3) Provide a minimum MERV 6 filter for the airflow passing over any surface
that is designed to condense water….
DISPLACEMENT VENTILATION
Copyright Price Industries, Inc. 2012 5
History of Displacement Systems:
• Utilized in Europe for over 30 years
• Origins in industrial facilities
• #1 choice for industrial facilities in Europe
• Applied to commercial market in the 1980’s
• Becoming popular in North America
Displacement Ventilation
Review of Mixing systems:
• 55°F Supply Air
• Mix the entire space
• Diffusers drive air motion
• High velocity supply
Displacement Ventilation
Copyright Price Industries, Inc. 2012 6
Displacement Systems:
• 65-68°F supply air
• Low velocity
• No mixing in space
• Heat sources drive air motion
• Stratified heat, contaminants
• Only conditions the occupied zone
Displacement Ventilation
Displacement Ventilation
Benefits• Air Quality (IAQ)
– More efficient contaminant removal
– High Ventilation Effectiveness
– Outdoor air can be reduced
• Local code permitting
• Thermal Comfort
• LEED & CHPS
• Quiet
Copyright Price Industries, Inc. 2012 7
Common Applications:
• Schools
• Theaters
• Casinos
• Airports
• Healthcare
• Halls & Conference Rooms
• Offices & Lobby Areas
• Restaurants & Cafeterias
• Industrial Spaces
Displacement Ventilation
Thermal Plumes:
• Create temperature stratification
• Carry contaminants from breathing zone
• Improve air quality in occupied zone
Displacement Ventilation
Copyright Price Industries, Inc. 2012 8
Thermal Plumes:
• Heat sources drive air motion
Displacement Ventilation
Layout:
• Air is drawn to heat sources
• Cool supply air flows around:
- Complex geometries
- Furniture
- Obstructions
Displacement Ventilation
Copyright Price Industries, Inc. 2012 9
2-10 °F Cooling 0‐5 °F Heating 5 °F+ Heating
Heating with Displacement:
Displacement Ventilation
Heating with Displacement:• Perimeter Radiation
• Diffusers with Integrated Heat
• Radiant Ceiling Panels
• Fan Coil Units
Displacement Ventilation
Copyright Price Industries, Inc. 2012 10
Installation examples:
Commercial Cafeteria
Displacement Ventilation
Worship Space
Installation examples:
Factory
OfficeDisplacement Ventilation
School
Copyright Price Industries, Inc. 2012 11
Installation examples:
Theater Office Meeting Room
Displacement Ventilation
Displacement Ventilation Velocity Profile
Displacement Ventilation – HealthcarePatient Room
Copyright Price Industries, Inc. 2012 12
Hospital Mockup• IAQ testing
• Tracer gas injected
• Test for:
• Ventilation effectiveness
• Contaminant exposure
Displacement Ventilation – HealthcarePatient Room
Hospital Mockup• IAQ testing
• Tracer gas injected
• Test for:
• Ventilation effectiveness
• Contaminant exposure
Displacement Ventilation – HealthcarePatient Room
Copyright Price Industries, Inc. 2012 13
Patient RoomOutsideCondition
Supply Type Airflow VentilationEfficiency
Summer
Low Sidewall DV 80 1.28
Overhead DV 80 1.14
Square Cone 80 0.65
Winter
Low Sidewall DV 80 1.14
Overhead DV 80 1.06
Square Cone 160 0.92
Displacement Ventilation – HealthcarePatient Room
AIR DISTRIBUTION METHOD OverheadDisplacement
Ventilation(low)
Displacement Ventilation
(high)
Supply Air Volume 290 190 190
Corresponding ACH 6 4 4
VENTILATION EFFECTIVENESS
1.24 1.41 1.27
Displacement Ventilation – HealthcarePatient Room
Copyright Price Industries, Inc. 2012 14
Waiting Room
Supply Type CFM ACH VE
Square Cone 1800 12 0.90
Overhead DV 1200 8 1.09
Low Sidewall DV 900 6 1.04
Displacement Ventilation – HealthcareHospital Waiting Room
HYDRONIC SYSTEMS (CHILLED BEAMS)
Copyright Price Industries, Inc. 2012 15
Hydronic SystemsHistory and Introduction
• Started in Europe ~ 60 years agoo Metal ceilingso Radiant systems
• Seeking more capacityo Passive chilled beams
• Integration of ventilation systemo Active chilled beams
Legend:
■ Application of radiant products
is natural
■ Additional care to control building moisture
■ Humidity must be carefully considered
Hydronic Systems
Copyright Price Industries, Inc. 2012 16
Why water?• Water holds ~ 3400 x more energy than air• Pumps more efficient than fans
Note: Ventilation air still required
Hydronic Systems
CBS Newsletter, Fall 1994 http:/eetd.lbl.gov/newsletter/CBS_NL/n14/RadiantCooling.html
The GOAL: Reducing Energy Required for Air Transport/Removal of Heat
Hydronic Systems
Copyright Price Industries, Inc. 2012 17
Thermal Comfort
• Three basic human comfort factors are:o Radiant comfort (40 to 50% of the human comfort factor)
o Fresh air/ air movement (30%)
o Humidity control (10 to 15%)
• Operative temperature is what a person will feel based on the interaction of radiant and convective
temperatures
Hydronic Systems
Hydronic System Concerns
• Potential for higher first costo What is the reference system?o Chiller requiredo Additional plumbingo Additional costs associated with
tighter envelopes
• Humidity control more importanto Condensation is a slow processo Transient spikes in humidity can be tolerated
as long as they are not more than a few hours and not a massive volume of moisture.
Hydronic Systems
Copyright Price Industries, Inc. 2012 18
Sensible only applicationDesign to avoid condensation – how?
Design:•Dew point + 2°F•Avoid or design for high latent load applications•Use dry air – DOAS
Hydonic Systems
Mumma, Stanley; 2002; Chilled Ceilings in Parallel with Dedicated Outdoor Air Systems: Addressing the Concerns of Condensation, Capacity, and Cost; ASHRAE Transactions 2002, Vol
108, Part 2; pp220-231
Exceeding dew point limit•Condensation process begins at dew point > surface temperature•Speed of process depends on environmental conditions
Sensible only applicationDesign to avoid condensation – how?
Sensing:Room humidity sensorsCondensation detection on piping
StrategiesWater on/offEntering water temperature resetSupply air water content
Hydronic Systems (Chilled Beams)
Copyright Price Industries, Inc. 2012 19
Hydronics Systems (Chilled Beams)
Benefits• Improved healing environment / low noise < NC 30
• Reduced plenum height• Reduced footprint (equipment or duct riser)
• Improved comfort• Superior humidity control• Superior room air velocity
Maintenance requirements are very low
• No filter – no filter changes
• Low velocity & dry coil minimizes dirt build up• Wide fin spacing reduces dust
bridging.
• Dry coils prevent dust from sticking
• Recommended cleaning by vacuum once every 1 to 5 years
Hydronic Systems (Chilled Beams)
Copyright Price Industries, Inc. 2012 20
Chilled Beams Operating Conditions
Hydronic Systems (Chilled Beams)
Cooling Heating
SAT 55 – 65°F 60 – 90°F
Airflow Rate 3 – 25 cfm/ft
EWT Dew point + 2°F 90‐140°F
Water ΔT 2 – 6°F 10‐20°F
Water Flow Rate min – 0.4 gpmmax – 2 gpm
Water ΔP 0 ‐ 10’
Air ΔP 0.2 – 0.75”target 0.4”‐0.6”
Design Recommendations• Select and position based on throw similar to a supply diffuser
• < 50 fpm air velocity in the occupied zone
• Select cooling EWT 2°F space dew point
• Keep hot water EWT < 140°F
Hydronic Systems (Chilled Beams)
Copyright Price Industries, Inc. 2012 21
Reduced primary air quantity• From 6 ACH to 2 ACH (100% OA)• Reduces fan power• Significantly reduces reheat requirement• Chilled beam chilled water return (62°F to 65°F)
can be used to provide reheat
Eliminates common return • Reduce hospital associated infection
Provides lower noise level & better healing environment
Active Beams in Health Care
Theory and Design Considerations
Patient Room• 300 ft²• 2 ACH = 90 cfm, 6 ACH = 270 cfm• Internal Cooling Load: 6,000 btu/hr sensible, 400 btu/hr latent
Item Chilled Beam VAV
Required Airflow 90 CFM 270 CFM
Outside Airflow 90 CFM 90 CFM
Supply Temp 55 54
Required Pressure .52” 1.0”
Coil LAT 50 54
CHWS Temp 57° F to 62° F 45° F to 55° F
Active Beams in Health Care
Patient Room Energy Example
Copyright Price Industries, Inc. 2012 22
Patient Room• Active Beam Selection
• 2’x8’ ‐ 6000 Btu/hr
Condition Result
Airflow 90 cfm
Sound NC 21 (@5”)
Pressure drop 0.55”
Water flow rate 1.35 gpm
Water head loss 6.9’
Active Beams in Health Care
Patient Room Energy Example
Energy Comparison
Notes: 1 kw per hp, 1 kw per ton, $0.10 per kwh, $1.00 per therm
Item Chilled Beam VAV
Fan Power per Room 0.103 bhp 0.308 bhp
Reheat per year 20.2 therms 159.3 therms
Overcooling per year 129 ton hours 1017 ton hours
Fan heat savings 291.6 btu/hr 874.8 btu/hr
Energy Savings 3,110 kwh & 139 therms per year
Cost Savings per Room $450 per year
Active Beams in Health Care
Patient Room Energy Example
Copyright Price Industries, Inc. 2012 23
Active Beams in Health Care
Jasper Memorial Hospital – Jasper, IN
Pharmacy section of hospitalHigh thermal comfortExpected to be used again in the
hospitalRenovation with low ceiling
heights
Active Beams in Health Care
Copyright Price Industries, Inc. 2012 24
• Laboratories
• Commercial Construction
• Owner occupied buildings
• Hospitals
• Educational facilities
• Historical Retrofits
Hydronic Systems
Radiant Panels
• Primarily radiant heating/cooling – no airflow
• Quick response to load demand
• Used along perimeters or spot cooling interior
• 2 types: Linear & Modular
Hydronic Systems
Copyright Price Industries, Inc. 2012 25
Hydronic Systems
Chilled Sails
• Radiant and convective cooling
• Increased performance over panels
• Profiles and free area encourage convection
• Architectural integration
Hydronic Systems
Copyright Price Industries, Inc. 2012 26
Laboratory Office Conference Room
Hydronic Systems
Chilled Beams
• Convective heating and cooling
• Higher capacities than panels and sails
• Integrated airflow for Active Beams
• 2 types:o Passive Chilled Beam
o Active Chilled Beam
Hydronic Systems
Copyright Price Industries, Inc. 2012 27
Laboratory AUDI Museum
Passive Beams
Hydronic Systems
Chilled Beam – Active, 2-way supply
Hydronic Systems
Copyright Price Industries, Inc. 2012 28
Active Beams
Hydronic Systems
Woods Lab, TN Bourne School, MA
Active Beams
Hydronic Systems
Copyright Price Industries, Inc. 2012 29
Suspended from slab Quick connect fittings
Hydronic Systems
Questions?