How to Save Energy When Your Pool is Closed

April 2020


In 2020 a Public School District Facilities Director contacted Desert Aire to ask for suggestions on how to save energy while the school’s indoor swimming pool was temporally closed due to the Coronavirus pandemic.   The director didn’t want to disturb a pool that was in an ideal state and felt that draining the pool wasn’t feasible due to the cost and time it will take to refill it, and to get the water chemistry back to safe levels.


To answer this facility director’s question, let’s take a closer look at what it takes to condition a typical indoor pool room and why.


Every indoor swimming pool room needs to maintain the room’s temperature and humidity setpoints to provide a comfortable and safe climate for the swimmers while preventing mold and mildew from forming.  Mold and mildew not only poses a significant risk to the swimmers health, it can also do significant damage to the building’s structure if left unchecked.  ASHRAE recommends keeping the room’s relative humidity (RH) at or below 60% in order to prevent mold and mildew growth.  ASHRAE also recommends bringing in outside air during the occupied hours to maintain good indoor air quality.


4 Ways to Save Energy When Your Pool is Closed


Keeping the above in mind, we recommend taking the following steps to lower energy consumption while your facility’s indoor swimming pool is closed.


  1.  Close the Outside Air (OA) damper to change ventilation air flow to zero with just enough exhaust to maintain the desired negative pressure.  Per the above; ASHRAE requires ventilation air during occupied hours only.  By shutting the OA damper, you will save energy by not having to condition the outside air prior to introducing it into the pool room.
  2. Lower the air temperature to 80 degrees F. Indoor pools should keep the room’s temperature 2 degrees above the water temperature to minimize evaporation.  While you can lower the room’s temperature setpoint below 80 degrees F, if you lower it too much, you run the risk of the dehumidifier going into cooling mode to cool a space with no occupants.  Also, most pool room dehumidifiers are designed for room temperatures above 78 degrees F.  They also operate more efficiently at or above 78 degrees F.  Conversely, keeping the room temperature above 80 degrees F at this time of year will increase the likelihood of the dehumidifier going into heating mode on cold spring days.
  3. Lower the Water Temp to 65F.  This can be done by lowering the pool boiler’s temperature setpointThis will not only save energy, it will also dramatically reduce pool water evaporation. If your dehumidifier is equipped with a pool water heating option, you will need to lower the pool temperature setpoint at the dehumidifier’s controller as well. Keep in mind that it will take about 3 days to raise the pool’s water temperature back to its original setpoint.  Please plan accordingly.
  4. Use a pool cover or a tarp to further reduce evaporation if possible. Why? Evaporation. The entire volume of a pool evaporates every year. Read our blog "How 3 Key Dehumidification Terms Relate" to learn more.

For more information about programing your dehumidification unit(s) to achieve your desired temporary temperature and RH, contact Desert Aire. You can also find a technician in your area, or submit a service request.