Recently a Public School District Facilities Director contacted Desert Aire to ask for suggestions on how to save energy while the school’s 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 pool room needs to maintain the room’s temperature and humidity set-points 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 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.
Keeping the above in mind, we recommend taking the following steps to lower energy consumption while your facility’s pool is closed.
- 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.
- 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 set-point below 80F, 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 78F. They also operate more efficiently at or above 78F. Conversely, keeping the room temperature above 80 at this time of year will increase the likelihood of the dehumidifier going into heating mode on cold spring days.
- Lower the Water Temp to 65F. This can be done by lowering the pool boiler’s temperature set-point. This 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 set-point 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 set-point. Please plan accordingly.
- Use a pool cover or a tarp to further reduce evaporation if possible.
For more information about programing your dehumidification unit(s) to achieve your desired temporary temperature and RH, contact Desert Aire at www.desert-aire.com/contact You can also go to www.desert-aire.com/find-a-techtechnician in your area, or submit a service request at www.desert-aire.com/dehumidifier-service/repair.