Back to Basics: Prepping Your Freeze Stats for the Freeze
Winter is here, and, if you have not already, now is the time to tackle some basic preparation and maintenance tasks on your commercial HVAC system. There are several important areas to check, and freeze stats are one of them. Follow these steps to make sure your freeze stats are ready for the freeze.
First, check that you have the proper controls and that they are working correctly. Freeze stats and low-temperature cutout controls are installed to protect your coils. Testing is not as simple as hitting a button because during install the copper tubing holding the temperature-sensitive gas can be compromised.
Here are some tips on how to test your controls:
- Make sure they are installed in the correct location—directly downstream of the hot water coil (upstream of your cooling coil) in a horizontal serpentine fashion, spaced evenly across the coil. This location will prevent false trips and provide full coil coverage.
- If the freeze stat comes with an adjustable temperature setting, set the temperature as low as you feel comfortable without dropping below freezing (35°F is typical).
- Buy freeze spray or ice and physically apply to 12 ̋-18 ̋ of the serpentine copper tubing that holds the temperature-sensitive gas vapor. The gas vapor pressure will drop and cause the freeze stat to trip.
- Verify the sequence of operations that occurs or that is supposed to occur when the freeze stat trips. This will typically include a shutdown of unit fans, closing of the outdoor air damper, and an opening of the hot water valve.
- Once complete, you will need to reset the freeze stat if it does not do so automatically. In some cases, you may need to physically reset the freeze stat as well as clear any front-end alarms that have been programmed to prevent the unit from automatically restarting after a freeze condition.
Kele has freeze stats and can offer technical advice to make sure your system is ready. Give us a call at 888.397.5353 if you have questions specific to your job. We are ready to help.