Heat pump vs electric btus different

[CoolPoolZ]

Im looking to heat a 5500 gallon pool and have learned on here to size up on heaters so it heats faster. When looking at the electric heaters i would need 100+ btus but apparently the heat pump of 50k btus will heat up to 13k gallons.

are they rated differently? Anything else i need to considerwhen choosing electric or heat pump heater for saltwater pool?

thanks

 

[ajw22]

Welcome to TFP.

Im looking to heat a 5500 gallon pool and have learned on here to size up on heaters so it heats faster. When looking at the electric heaters i would need 100+ btus but apparently the heat pump of 50k btus will heat up to 13k gallons.

What you are missing in the above statement is the time to reach a given temperature. A 50K BTU heater, regardless of power source, will take twice the amount of time to heat as a 100K BTU heater.

 

[CoolPoolZ]

Ok thanks thats a good point. I heard heat pumps can keep the temperature warm for less $ than an electric heater but that it takes longer to heat up. Am I right in thinking the issue would be just with the first heat up of a freshly filled pool or any major temperature drops due to weather?
I don’t have gas nearby so cant go that route. Thanks

 

[JamesW]

An 11kw electric heater is 37,534 btu/hr and takes 48 amps at 230 volts.

For comparison, a 70,000 btu/hr heat pump uses about 18 amps at 230 volts, which is 4,140 watts.

A heat pump has a coefficient of performance of about 5.7, which is 5.7 times more efficient than an electric resistance heater.

The amount of heat per dollar is about:

Heat pump...........165,000 btu
Nat. Gas.................74,500 btu
Electric....................28,500 btu.

5,500 gallons is 45,870 lbs.

An 11kw electric heater will raise the water temperature about 0.82 degrees Fahrenheit per hour.

A 70,000 btu/hr heat pump will raise the temperature by about 1.5 degrees Fahrenheit per hour.

Does not account for heat loss.

Note that heat pump performance depends on the weather conditions.

During very cold weather the heat pump performance is significantly diminished.

 

[sktn77a]

Chicago? Gas!

 

[JamesW]

Chicago? Gas!

I don’t have gas nearby so cant go that route. Thanks

 

[JamesW]

A heat pump is the way to go unless you need to heat during cold weather.

If you go electric, it is very expensive, but the small size of the pool might make it affordable depending on how much you care about the cost.

11Kw is typically the maximum for residential electric heaters.

There are bigger electric heaters if you have the power supply and enough money available.

11kw is 48 amps. So, double that and you're near 100 amps.