Expected more from a 110,000 BTU heat pump? Is this normal?

[D0T-C0M]

I have a 27' AG salt water pool (roughly 17,000 US gallons). Last night I installed my 110,000 BTU heat pump. The pool was 70f and I let it run all night (with solar blanket on, ambient temperature around 55f) and the temperature only raised to 71f this morning. I was expecting at least 3f or 4f increase. Is this normal?

I checked using an infrared camera and the outlet is 3f-4f higher than the inlet

 

[cowboycasey]

I think for that size heater and that much water with the outside temp in the 50's that is not bad... most go with a 400,000 BTU heater to heat faster

 

[Swampwoman]

Did you choose a heat pump because you don't have natural gas? (Eg I know in Nfld they don't due to granite, but don't know about NB). What was your overnight temp last night?

My understanding in general has been that heat pumps have trouble getting up to temp in cooler weather and are better at maintaining than raising. That's why in Mchigan, with very cool night temps in the early season, I'm better off with NG.

If that's an option for you and you're considering at some point switching out, you may wish to consider.

If NG/swapping out isnt an option, maybe you could supplement heat in early season with solar?

 

[cowboycasey]

Thanks SW, I missed the "heat pump" most everyone has natural gas and my brain went there.. for a heat pump that really was a good rise, they are designed to be left on, it will take longer to get to the temp you want but they are great at keeping a set temp, you will get most of the temp rise from a heat pump during the day

 

[pooldv]

Heat pumps operate on a curve where BTU output drops relative to ambient temperature. Efficiency is pretty low in the 50s and improves quite a bit in the 60s and 70s.

 

[Michgmr]

I agree with pooldv the hotter it is outside the better the heat pump works. Living in New England I don't even bother to run my heat pump at night if the temps ate in the low 60's or lower. I also schedule the filter to run from 11am- 9pm so that the Heat pump runs when the outside temps are at their highest. Running early morning when temperature outside is cooler does not work great. My Heat pump is 117500 BTUs and if it is in the mid to high 70s I can get an 10 degree increase in a 8 hour cycle. So it is pretty good given that i have a 35k gallon pool. Definitely need to use a solar cover at night if you heat and it is in the seventies with a solar cover at night you can get very good temp increase still.

 

[CJadamec]

Best to leave the cover on and run the heat pump when the sun is out and air Temps are highest. It will take a day or two with the cover on to get up to temp.

 

[Marty D]

My 140 heat pump only raise the temp from 68 to 70 the first time I use it when water was cold. The 2nd night it went up 8 deg. 3 rd night she hit 80 deg. Your pump is working. I now have 80 deg water day and night without the heater. When the kids come on Sat I put the heater on Friday night and sat morn it's 86 deg. Yes, we like our water hot!!! Your elec bill will not be much. My bill was less then $100 but I ran the heater all month just when it was 70 outside. We all woke up last sat and it was 55 deg in morn. The hole back yard was smoke from the pool being 86. I saw $$$$ floating in the sky.

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Also I have a 3 speed pool pump. I use different speed to see what works best when heater is on. This was hard to do, it took me all month. Right now I would have to say slower speed works best. No more then 2250 RPM. This is still in test.

 

[D0T-C0M]

My 140 heat pump only raise the temp from 68 to 70 the first time I use it when water was cold. The 2nd night it went up 8 deg. 3 rd night she hit 80 deg. Your pump is working. I now have 80 deg water day and night without the heater. When the kids come on Sat I put the heater on Friday night and sat morn it's 86 deg. Yes, we like our water hot!!! Your elec bill will not be much. My bill was less then $100 but I ran the heater all month just when it was 70 outside. We all woke up last sat and it was 55 deg in morn. The hole back yard was smoke from the pool being 86. I saw $$$$ floating in the sky.

- - - Updated - - -

Also I have a 3 speed pool pump. I use different speed to see what works best when heater is on. This was hard to do, it took me all month. Right now I would have to say slower speed works best. No more then 2250 RPM. This is still in test.

Best to leave the cover on and run the heat pump when the sun is out and air Temps are highest. It will take a day or two with the cover on to get up to temp.

Ok I guess it was only the low ambient temperature which was making the heat pump inefficient. I let it run during the day and It made it from 71f to 84f by days end.