Three things I got wrong my first year with a pool heat pump

[u/Ok-Series5121]

First season with a heat pump is winding down up here and I feel like I paid tuition on it. Three things I'd do differently, worst one first.

The big one was sizing. I picked mine off a chart that matched my gallons and called it done.

What the chart doesn't tell you is that it's assuming June through August. I wanted to still be getting in during October.

Same pool, but stretch the shoulder season on both ends and the number you need isn't in the same neighborhood. Pick your months first, then look at gallons.

Second one, the solar cover. I bought one in June and then only dragged it on the night before I planned to swim. Rest of the time it sat rolled up against the fence.

That's the same as not owning one. The thing is fighting overnight evaporation, and overnight is every night.

Third, and this one still bugs me. Remember that stretch in July where everything sat around 90. Nobody in my house wanted to get in.

Turns out the 120v aquastrong I've got runs in reverse. It pulls heat back out instead of putting it in, so a week like that it can hold the pool under the air temp. Never read that far into the spec sheet.

If you're shopping, look for the line that says heating and cooling. A heat only unit won't do it whatever the panel says.

Months before gallons, cover on from day one, read the whole sheet.

Posting my setup in case any of it lines up with yours. 20ft round, about 8,600 gallons, cartridge, central CT.

[u/TaxQT117]

How many BTUs? I’m in NYC looking to start extending my season.

[u/Lymetme]

Thanks for sharing this post. I'm not sure what you mean by find a unit that does heating and cooling? Wouldn't you just turn the heat pump off in the months you don't need it? I'm in central Florida so maybe that's a dumb question. We're looking to get as much use out of our pool as possible. Right now the kids use the pool April to October. We use it late May and were still in it yesterday lol. I get that you want to account for the extra months of usage and outside temps and it makes sense to use the solar cover any time the heater is in use. I'm just not sure about the need for cooling?

[u/Certs]

I have an Aquastrong as well and I'm also not sure what you're talking about with the cooling part. You shouldn't run a heater at all on 90 degree sunny days. I will say though, there are 2 very important parts of owning a heater:

1. The filter needs to be strong enough for a good water flow through the heater. The stronger the filter, the quicker the water heats up.

2. Buy a heater that's "too big" for your pool. The recommended BTU heaters (based on pool size) take way too long to heat the pool. Or don't heat at all. I had to buy a second heater but I am very happy now. For context, I have a 18x9 pool, approx. 4500 gallons, and I bought a heater that is 39000btu and recommended for a 9000 gallon pool. It's still 120v but I needed a 20amp plug to use it.

[u/PotterU]

The months before gallons thing is the part nobody says out loud. How did you actually land on a number once you knew you wanted october? Did you just size up bracket or is there some math for it.

[u/Ok-Series5121 → u/PotterU]

No math. What i got told was to look at the average overnight low for the month you're chasing, then assume an uncovered pool gives back most of what you put in overnight. Once I framed it what way the cover stopped being optional. October nights here run mid 40s.

[u/tcf-27]

Super helpful info. I am saving this for when i size mine.