Cleanrooms: “Top Five” Energy Efficiency Strategies by Building Type

“Cleanrooms” are highly specialized research environments with intense need for particulate control.  Cleanrooms often have additional extreme needs, such as humidity sensitive processes or corrosive exhausts.  As seen in the above photo, cleanrooms can have photo sensitive processes requiring specialized and/or high intensity lighting.

The most effective EEMs for Cleanrooms are those that target airflow efficiency and reducing hazardous exhaust generation. Of critical importance are technologies that reuse “waste” heat / cool from the exiting exhaust air.  Electrical EEMs can be very effective, and result in real savings in both energy usage and energy costs, but are small in comparison to HVAC EEMs.  EEMs that target the building envelope, such as increased air tightness and reduced glazing %, are critical to the stability of the indoor environment, but have minimal impact on overall energy use.

Our “TOP FIVE” EEMs for Cleanrooms are:

  1. Optimize Cleanroom Location
    • Keep the cleanroom away from the building perimeter
    • Use hallways or support spaces (i.e. storage, not other clean labs of any kind) to separate the cleanroom proper from the exterior.
    • Key issue: tight humidity (“dewpoint”) control vs. exterior wall (particularly glazing)
  2. Demand Control Ventilation
    • Timeclock for facilities with minimal night use (night/unoccupied setback)
    • Occupancy sensors (unoccupied setback)
    • Particle counters (quick ramp up / slow decay)
    • Pressure differential sensors (to ensure that the cleanroom does not become negatively pressurized relative to the exterior or to adjacent spaces).
    • Limit dewpoint control to critical areas only
    • Variable volume system, including variable volume exhaust/makeup
  3. Low Static Pressure System
  4. Optimize Airflow Safety Device (Process Bench) Selection
  5. Optimize Mechanical Equipment
    • High Efficiency BOILERS, chillers, cooling towers, etc.
    • Use central plant resources if available (chilled water, steam, campus co-generation, etc)
    • 100%OA system with Heat Pipe AHU
    • Heat recovery chiller for sub-cooling and “free” reheat
  6. High Efficiency Lighting
    • with Occupancy Sensing in non-critical zones

 

“GO BEYOND” STRATEGIES

  1. Harvest MAHU CW return loop
  2. LED Lighting

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