Biology / Pharmaceutical Labs: “Top Five” Energy Efficiency Strategies by Building Type

“Biology” and “Pharmaceutical” Labs have moderate chemical use and few fume hoods.  Their energy use is dominated by the need to heat, cool, and move huge amounts of air, to maintain the required “Lab Air Change Rate”.  The Air Change Rate is a worker safety requirement specified by building codes and standards, and enforced by the laboratory’s Environmental Health and Safety (EHS) personnel.

Air change rates are commonly specified in “air changes per hour”, or the number of times per hour that the total volume of room air is exchanged for fresh outdoor air.  Most research laboratories use 6 ACH as a “standard” for safe laboratory design.  6 ACH is roughly equal to 1 cubic foot of outdoor air, per minute, per square foot of floor area, per ten feet of ceiling height.  This is approximately five times the air exchange requirement of an office space (1CFM/sf ÷ 20CFM/person * 100sf/person = 5x).  This results in a massive energy demand for heating, cooling, dehumidifying, and moving this very large volume of air through the building.

The most effective EEMs for Biology / Pharmaceutical Labs are those that target reducing air flows, decoupling heating / cooling from ventilation, and /or reusing “waste” heat / cool from the exiting exhaust air.  Other mechanical / electrical EEMs can also be effective, but have relatively less impact on the total energy usage.  EEMs that target the building envelope, such as increased building insulation, reduced glazing %, triple glazing, or reduced thermal bridging, have far diminished returns.

Our “TOP FIVE” EEMs for Biology / Pharmaceutical Labs are:

  1. Optimize Building Program distribution (space planning for energy efficiency).
    • Consider planning separate “office zones” that are driven by different AHUs (to allow partial use of recirculated air)
    • Don’t put fumehoods in small, enclosed rooms
    • Consider an HVAC strategy that uses enthalpy wheels on lab ACH (with a bypass for fumehood air). If so, use most efficient fumehoods possible.
  2. Separate heating / cooling delivery from ventilation delivery
    • Strategies include: radiant slabs, radiant panels, within-lab fan coils, chilled beams, fan filter units, humidification / dehumidification equipment, and/or specialized “packaged air handling units”
  3. Demand control ventilation
    • Via chemical concentration detection (“Aircuity”) in lab spaces
    • Unoccupied mode for lab ventilation, including setback for fresh air delivery, temperature stability and setpoint, and humidity stability and setpoint
  4. Optimize mechanical equipment
    • High Efficiency Boilers, chillers, cooling towers, etc.
    • Use central plant resources if available (chilled water, steam, campus co-generation, etc)
    • 100% Outside Air Ventilation System
    • Enthalpy Wheel AHU
      • We note that use of Enthalpy (“Heat”) Wheels in laboratories requires careful consideration. Fumehoods should only be connected to enthalpy wheel AHUs after careful study of the chemical processes to be used in the hoods has determined that cross contamination is highly unlikely.
      • Under some circumstances, fumehoods can bypass the enthalpy wheel without significant energy penalty to the overall building systems.
    • Airside Economizer
  5. Optimize Building Envelope
    • <40% glazing
    • Avoid thermal bridging and maximize air tightness.
    • NOTE: Wall R values don’t matter as much
  6. High Efficiency Fluorescent Lighting
    • Low Ambient / Targeted Task lighting. Design the space to be “dim but pleasant”, with localized task lighting at work areas.
    • Daylight Dimming
    • Vacancy Sensing

 

“GO BEYOND” STRATEGIES

  1. Geothermal Heat Pump
  2. LED Lighting

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