Undersized heat pump -- what to do?

ninjajim4

Well-known member
May 25, 2023
69
chicago
Pool Size
4545
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
Hi all, happy opening season!

Looking for some input on heating for the upcoming season. I currently have this little guy:


I found that it *seemed* like it was acceptable but certainly found even in the mid to low 70s with drops in the night that it really wasn't keeping up or doing much at all. Probably to be expected given its BTU rating. I'm looking at two options here:

1) selling it at a loss and getting a large heat pump or gas heater

2) doubling down and getting a second one of these little guys and running in parallel

the pros for the second option are that I already have a sunk cost into it that I won't have to take the hit on and they're relatively cheap for a second one. All-in, I'm still well under half the price for a bigger better unit.

the cons are that the BTU output will still be less than half of anything else I end up buying, but maybe it's sufficient for what I have? I also don't have a sense of what the electricity bill works out to from an efficiency perspective running two of these as compared to one big heat pump or gas heater.

Also considering the use case, which is that we're not going to need this all that often and heat pumps are slow. So on the balance, it feels like it might be more cost effective to fire up a gas heater on an as needed basis. The cons or at least question is the expense of the heater and how long to break even on the savings vs the initial overhead. And also that I don't actually HAVE an accessible gas line (which I do want for our grill anyway so maybe the cost on that is sort of a wash).

Thank you as always for weighing in!

Welcome your expert thoughts as always.
 
Your pool is @ 5k gallons right? That heater is 15k BTUs, which isn't much. What it your budget? If the budget allows, you can't beat a gas heater.

For costs to run, you could probably wire up a Kil-o-watt meter on it and see. Amazon.com : kilowatt meter

I would think in Chicago you're still too cold for a heat pump to do much of anything. How did it perform last season?
 
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Your pool is @ 5k gallons right? That heater is 15k BTUs, which isn't much. What it your budget? If the budget allows, you can't beat a gas heater.

For costs to run, you could probably wire up a Kil-o-watt meter on it and see. Amazon.com : kilowatt meter

I would think in Chicago you're still too cold for a heat pump to do much of anything. How did it perform last season?

The pool is 4.5K gallons I believe.

I don't know if we really have a budget...? Just kind of weighing the benefits of having this vs the cost and the full price seems hard to swallow but looking at some secondhand units south of 2K seems palatable enough to swallow.

I THOUGHT this little guy was a good supplement for running in conjunction with the sun. But as temperatures dropped below 80 especially at night, it became apparent that it wasn't keeping it up at all, not even maintaining while covered overnight and moving up a degree or two in the daytime, which could have been just the sun. Overall felt like it wasn't cutting it at all. It certainly wasn't heating up a degree every 2 hours or so, which about what I expected it should do.

Is the pool covered when not in use?

Yes, we use a solar cover when not in use, and if it's not warm and sunny out. I will typically undercover it during the day to get the direct sunlight on it if conditions are favorable.
 
The low output of that heater coupled with your cold northern temps coupled with having an above ground pool make that heater almost a total waste of money to operate. Bottom line you need more BTUs. You can add another heat pump but they are more and more inefficient the colder it is. Gas is the best option but that will run a lot of money both for installation and running. My 400k BTU costs close to $5/hour to run.
 
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The low output of that heater coupled with your cold northern temps coupled with having an above ground pool make that heater almost a total waste of money to operate. Bottom line you need more BTUs. You can add another heat pump but they are more and more inefficient the colder it is. Gas is the best option but that will run a lot of money both for installation and running. My 400k BTU costs close to $5/hour to run.
Thanks for your insights. I think will look around for a decent gas heater then