Heat Pump: run every day or crank it when needed?

[david11050]

For all of the family to enjoy the pool, I need to keep the temperature in the 88-90F range. The pool is mainly used on the weekends and some three day weekends during the summer.

Is it more efficient to turn the heater off Sunday night and then turn it on 24 hours before its needed (Thursday or Friday morning) and run for 24-36 hours to get to temperature? Or leave the heater on the same temperature all week/season?

When its hot mid summer, I can get to temperature in a day with the sun hitting the pool. At the start and end of season with cooler nights, I feel like I have to run it 24/7 to maintain temperature.

When only running the pump and heater 8 hours a day, is it more efficient to run during the afternoon to get the suns help in heating the pool or run at night to prevent heat loss from the cool down?

 

[Joshii]

It seems counter-intuitive, but it will be better to leave it off and crank it when needed. Even though you'll be running it a lot then on a single day, you'll doing it cumulatively for much less time. Same advice for upping/downing the thermostat when you leave your house and "cranking it" just before you get home. Again, seems counter-intuitive, but all the science backs it.

Now of course, none of that will help you if you want to take a quick dip on a Wednesday night...

 

[PoolGate]

Heat pumps are not good for on-demand applications. You really need to keep it on all the time to have the temp you want when you want it. Gas heat can be turned on/off as needed. You could set the thermostat for a bit lower when not in use but keep in mind that a heat pump will do 1-2 degrees/day max rise in temp so plan accordingly.

 

[harleysilo]

My understanding is that my heat pump is more efficient running at higher outdoor temps, therfore I primarily run it during the hottest part of the day. However I use mine daily when I need it. For on demand application I would let it run 24/7 and that gets expensive.

Do you have a cover for your pool when it's not being used?

I get a 10 degree rise each day but I have an opaque cover that is always on elminating evaporation and the cooling it causes. If I turn it off overnight I'll loose anywhere from 4-8 degrees. So over several days i can bring it up 10 degrees or more (from starting temp) and then hold steady at that.

 

[ps0303]

On the spot heating is best when you have a gas heater. A heat pump can take a very long time to heat and thus sometimes you have to run it for a few days or so to heat. Especially if you have cool summer days/nights.

 

[pooldv]

I try to run my heat pump during the day in spring and fall for a couple of days to heat the pool for the weekend. With the cover on and the pump off overnight the heat retention is usually pretty good in my pool. But, sometimes you just have to run it all out to get there.

 

[BMK]

We keep the pool at a constant temp. throughout the season. I swim laps early in the morning and my wife (who likes the pool temp only slightly less than the hot tub), kids and assorted friends / family use the pool spontaneously throughout the day and evening. We want our pool temps to be consistent regardless of when we want to jump in...no waiting, no planning hours ahead. For our type of use, we pretty much set the thermostat (about 89) on the heat pump and forget about it. Works out fine for us. I will turn it down some when I know the pool will not be used for a few days or more. I must mention that we have an auto-cover that more often than not is closed when the pool is not in use. This helps tremendously with heat retention and keeping the heat pump from having to work very hard. A good cover, any type, is essential for efficient heating in this neck of the woods.

 

[mas985]

Assuming you have a 150k BTU heater, it will raise the pool temp about 0.5 degree per hour at most.