PoolBrews
Well-known member
- Oct 16, 2019
- 552
- Pool Size
- 6750
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite Pro (T-15)
If you look at the efficiency rating, you will see that the larger heaters have a much better rating than the smaller heaters - i.e. they cost less to run. It's not just about fast. If you get the larger heater, you get fast and efficient. I would always go with the largest heat pump available. I have a 7K pool with a 144K Hayward heater and I keep my pool at 89 all winter with no issues in central Florida. If you go too small, it's a very costly mistake. For only a couple hundred more you can install the largest available. In addition, the larger heater will run less which should translate to greater longevity.It is about how fast, not efficiency.
A larger HP will use more Kw for a shorter period of time then a smaller HP running longer at lower Kw. Their electrical use per BTU will be about the same.
You pay once for the larger BTU HP and then have the flexibility to heat in colder conditions. Efficiency during operation is about the same.