I have an aqua cal heat pump. Pool water is starting to get to consistently in the low to mid 90's (on occasion high 90s). What is the best way to cool the salt water pool? Run the chiller on the heat pump with the Autopool cover on or off? I like to get it to high 80's (i.e. 88 or 89 degrees). Currently, I run the pool filter pump 24/7. My first true pool season with this pool, so trying to figure out the best methods. Also, how quickly does a chiller drop the temperature of a pool so I know what to expect. Thanks.
How to Best cool down pool with a heat pump? Cover on or off?
- Thread starter quantase
- Start date
- Jul 21, 2013
- 52,233
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Open the cover for evaporation cooling at night when the night temperature is less then the pool water.
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Cooling A Pool - Further Reading
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I don’t run my pump for more than a few hours a day, I find if I run it during the day, then the pool temperature increases, if I run it at night it decreases.
I imagine that running it during the day, means the surface water under my autocover that is heated by the sun is constantly getting mixed and replaced with cooler water. Where as if the pump doesn’t run, it is mostly the surface water that gets heated, and the heat gain reduces as the surface water is heated.
If I run the pump at night, the surface water is cooled as the air temperature is lower than the pool water, if there is no circulation it is mostly the surface water that is cooled, and as the temperature difference between water and air is reduced, the heat loss is reduced. By running the pump at night, the surface water is constantly replaced, and the temperature difference between water and air remain more or less constant, resulting in a larger cooling effect.
If you don’t need to run the pump 24x7, you might find that only running it between sunset and sunrise, will result in a net cooling effect.
I imagine that running it during the day, means the surface water under my autocover that is heated by the sun is constantly getting mixed and replaced with cooler water. Where as if the pump doesn’t run, it is mostly the surface water that gets heated, and the heat gain reduces as the surface water is heated.
If I run the pump at night, the surface water is cooled as the air temperature is lower than the pool water, if there is no circulation it is mostly the surface water that is cooled, and as the temperature difference between water and air is reduced, the heat loss is reduced. By running the pump at night, the surface water is constantly replaced, and the temperature difference between water and air remain more or less constant, resulting in a larger cooling effect.
If you don’t need to run the pump 24x7, you might find that only running it between sunset and sunrise, will result in a net cooling effect.
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This makes sense thanks. So should I leave the autocover on without pump circulating or autocover off without pump circulating during the day in the sun to have it the coolest?
I have my cover on at all times when we’re not using the pool, mainly to reduce evaporation and keep it clean. But as far as cooling, evaporation cools, so if the main goal is cooling you might be better off with the cover open. If you experiment, please let us know what you find.
I left my autocover on with pump and heat pump off from 10am until 4pm. Air temp In the morning was 81degrees and got up to 98 degrees. When I uncovered the cover at 4pm, surface water was hot (101 degrees). Below surface was chilled. I then turned pump on to circulate water and water temperature went to 90 degrees where we like it. Leaving it covered without pump running definitely kept it cooler than if we had cover on and ran the pump. I would think it would have been hotter even if we had the heat pump on with the cover on or off.
