ventilation and energy in healthcare...
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
Ventilation and Energy inHealthcare Buildings
Jeff Elsner, P.E.Mechanical Engineer
The RMH Group
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
Agenda
§ Healthy Ventilation:Why it's Important
§ Correctly Calculating VentilationRates in Healthcare
§ The Energy Impact of Ventilation§ Alternate Systems for Delivering
Required Ventilation and theirperformance
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
Ventilation: Why it's important
“Without high-quality ventilation in health care
facilities, patients, health care workers and
visitors can become infected through normal
respiration of particles in the air.”— ASHRAE Standard 170
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
WHY VENTILATION IS IMPORTANT
Ventilation and Infection Control
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Source: World Health Organization
2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
WHY VENTILATION IS IMPORTANT
Infection Rates and Costs
§ Hospital acquired infections are a huge expensefor health systems that we as HVAC engineershave a direct affect on.
§ Estimates of nosocomial (hospital acquired)infections that are caused by airborne agentsrange between 10% and 33% (of all nosocomialinfections) and infect approximately 1% of allhospital patients, costing 4 to 5 billion dollars peryear.
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
WHY VENTILATION IS IMPORTANT
Another Look at Ventilation andInfection Control
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
WHY VENTILATION IS IMPORTANT
Ventilation as Piece of an OverallInfection Control Strategy
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
HEALTHCARE VENTILATION RATES
Governing Codes and Standards:
§ AIA/FGI guidelines§ ASHRAE 170§ International Mechanical Code/Local codes for
non-healthcare spaces§ Others?
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
For a HVAC system servingmultiple zones, what is thecorrect way to calculate theventilation rate at thesystem level?
A. The sum of the outdoor air required in each zoneB. Percent outside air equal to the highest required
percentage in any zoneC. Calculate the outside air required per the
Ventilation Rate Procedure in ASHRAE 62
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
Answer:C. Use the Ventilation Rate Procedure
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
HEALTHCARE VENTILATION RATES
The Biggest Numbers in HealthcareVentilation
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
HEALTHCARE VENTILATION RATES
A Practical Matter, How Do We Apply62.1 ?
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§ 62.1 uses airflow rates in CFM/ft2 andCFM/person
§ 170 uses airflow rates in Air Changes per Hours
2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
HEALTHCARE VENTILATION RATES
The ASHRAE Standard SpreadsheetStill Works
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
HEALTHCARE VENTILATION RATES
Typical Calculation
§ Results: More than the sum but usually less than 30%§ Limit heating supply air temp to avoid a penalty for
supplying warm air from the ceiling§ Minimum total air change rate helps keep % OA down
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
HEALTHCARE VENTILATION RATES
Fun Fact: Minimum Flow Rate
§ What's the minimum flow rate to keep somebodybreathing in a totally sealed room?
§ Based on 0.9kg O2 (NASA's budget for one astronaut eachday)
§ =2lb O2, 9.4 lb of Air, 124 ft3 all per day, .086CFM/Person
§ Would indicate that you could pack almost 3 people persquare foot without anybody dying (from lack of O2anyway)
• Does not account for dilution of CO2 or other contaminates§ Compare to lowest Standard 62 value of 5 CFM/Person
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
HEALTHCARE VENTILATION RATES
Fun Fact: Minimum Flow Rate
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
VENTILATION and ENERGY
Energy Metrics
§ According to ENERGY STAR, the median hospital inthe Rocky Mountain region uses389.8kbtu/sf/year of source energy
§ Each patient room is using energy equal to burning2 gallons of gas a day.
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
VENTILATION and ENERGY
Mechanical Ventilation RequiresEnergy Both to Move and Condition Air§ Main consumers for typical VAV reheat systems
• Fan power• Outside air conditioning (heating and cooling)• Cooling• Re-heat
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
VENTILATION and ENERGY
Site and Source Energy
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
VENTILATION and ENERGY
Engineers Have Limited Ability toReduce Fan Power Energy§ Constrained by required airflow rates, filtration,
and duct design
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
VENTILATION and ENERGY
2 ACH Outside Air – Sometimes It IsNot 55 Degrees§ Outside air pre-conditioning§ First of all - supply the right amount§ Both temperature and, depending on the areas
served, humidity
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
VENTILATION and ENERGY
Heat Recovery Window is ActuallyFairly Small in Denver
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
VENTILATION and ENERGY
Cooling Load
§ Plug loads are usually out of the design teams control§ Some efficient forms of cooling are off limits (e.g.,
chilled beams)§ Lighting is a great opportunity but this presentation
assumes code level lighting.
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
VENTILATION and ENERGY
Re-heating is Not Our Friend
§ That leaves Re-heat§ Its significant and It’s not
required!
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
A Model used to Evaluate Performance
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• 19,000 SF patient wing• 36 rooms + support
spaces
• 4,000 SF OR suite• Six rooms + support
spaces
2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
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Four Pipe Fan Coil Units with DOAS
2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
Four Pipe Fan Coil Units (with DOAS):System Overview
PROS§ No re-heat§ Dedicated Outside Air
System suppliesneutral air
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CONS§ No economizer§ Final filters at each
zone§ Cost of each zone§ Chilled water, hot
water, and ductworkto each zone
2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
Four Pipe Fan Coil Units (with DOAS):Patient Wing Performance
§ 8% Energy Savings§ 14% HVAC Energy Saved§ 9% Energy Cost Savings
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
Four Pipe Fan Coil Units (with DOAS):OR Suite Performance
§ 4.5% Energy Savings§ 6.5% HVAC Energy Saved§ 13% Energy Cost Savings
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
Four Pipe Fan Coil Units (with DOAS):Caution: Labor Cost of Filter Changes canOffset Energy Savings
§ Example: 45 zones, 23,000 sf§ Materials
• 45 filters x $50 each x 1/year = $2,250/year§ Labor
• 1h x 45 filters x 1/year = 45 hours/year• $5000 (energy cost savings) - $2,250 (materials
cost) = $2,750 net savings• Net savings / 45 hours = $61 per hour
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
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VRF Fan Coil Units with DOAS
2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
VRF Coil Units (with DOAS):System Overview
PROS§ No-reheat§ Dedicated Outside
Air System suppliesneutral air
§ Moves heat betweenspaces
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CONS§ No-economizer§ Final filters at each zone§ Cost of each zone§ Potential for refrigerant leaks§ Refrigerant machine room code
requirements
2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
VRF Coil Units (with DOAS):Patient Wing Performance
§ 13% Energy Savings§ 22% HVAC Energy Saved§ 14% Energy Cost Savings
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
VRF Coil Units (with DOAS):OR Suite Performance
§ 11% Energy Savings§ 17% HVAC Energy Saved§ 7.5% Energy Cost Savings
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
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Dual Duct VAV
2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
Dual Duct VAV:System Overview
PROS§ No-reheat§ Hot duct supplies
neutral air whenheating is not needed
§ Enhanced Heatrecovery window
§ No piping required inbuilding
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CONS§ 4 duct systems in the
building instead of 3(Cold, Hot, Return,Exhaust)
§ Larger boxes
2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
Dual Duct VAV:Patient Wing Performance
§ 15% Energy Savings§ 26% HVAC Energy Saved§ 7% Energy Cost Savings
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
Dual Duct VAV:OR Suite Performance
§ 11% Energy Savings§ 15% HVAC Energy Saved§ 11% Energy Cost Savings
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
Dual Duct VAV:Enhanced Heat Recovery Window
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
ALTERNATES to VAV RE-HEAT
Dual Duct VAV:Key Considerations§ OA Routing
• Which deck does the outside air go to?§ Humidification
• How do you control maximum humidity• Where do you put your humidifiers?
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
REFERENCES
1. http://www.who.int/csr/resources/publications/whocdscsreph200212.pdf?ua=1
2. http://orf.od.nih.gov/PoliciesAndGuidelines/Bioenvironmental/Documents/RoleofACHinTransmissionofAirborneInfections508.pdf
3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2870817/#!po=25.0000
4. Modeling Software – Trane Trace, eQUEST
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2014 ROCKY MOUNTAIN ASHRAE TECHNICAL CONFERENCE VENTILATION AND ENERGY IN HEALTHCARE BUILDINGS
Questions?
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