Prepare Your Building for Extreme Cold Weather

As many of you are aware, Chicagoland is forecasted to experience severe cold temperatures over the weekend and into early next week with lows occurring at or below zero with the forecasted overnight low this Sunday being -7˚ F. The forecast projects temperatures that will test the limits of the heating capabilities of your equipment. In advance of this and other extreme cold weather events, it is important to make sure your building is prepared.

We recommend taking the following steps to ready your building for the extreme cold, especially if you have made changes to how your ventilation system is operating since last winter, or you have new equipment experiencing extreme weather for the first time:

  • Turn off all non-critical exhaust systems (i.e. residential kitchen and toilet exhaust)
  • Temporarily reduce ventilation only where possible
    • DO NOT turn off 100% Makeup Air Units (MAUs)
      • If 100% MAUs shut down unexpectedly and cannot be restored, we advise shut down of the associated toilet and kitchen exhaust systems
      • Consider increasing the discharge air temperature setpoints for boosted heating and pressurization
  • Override unoccupied and overnight setbacks to occupied
  • Consider adjusting thermostat setpoints to minimum heating (i.e. 68F-70F) to ease stress on central equipment
  • Avoid scheduled shutdowns of systems
  • Avoid turning heating related equipment off
  • Verify all coil pumps are operational
    • DO NOT shut coil pumps off
  • Maintain continuous operation of all heating related pumps
  • Minimize infiltration
    • Keep doors, windows and other openings sealed
    • Add temporary heat where infiltration can’t be controlled
    • Maximize pressurization if possible
  • Keep blinds and shades closed on windows at night and those not receiving direct sunlight during the day
  • Perform a system check of all heating critical equipment
  • Remove snow and ice to ensure proper airflow form outdoor air-based heat pump systems
  • Verify the operation of all low-limit safeties such as freezestats to protect equipment
    • Ensure the sequence of operation is followed upon a freezestat trip (Example: outside air dampers properly shut and can be reopened)
  • Verify the operation of all backup or redundant heating equipment not normally used
  • Verify the location of isolation valves, verify their operation and understand when to use them
    • During an emergency situation where a pipe, coil or other system has frozen, the reliability, and proper use of isolation valves is critical
    • Isolate the leak to as local an area as possible
    • Take care not to close the wrong valve (essentially stopping the flow of water)
      • Water at rest is much more likely to freeze. Therefore, do not risk further freezing of the system by closing the wrong valve, should isolation be required

For more information or to address specific concerns or questions, please contact us at