Heat pump pool heaters

Heat Pump Pool Heaters

Heat pump pool heaters are a type of electric swimming pool heater that uses electricity to do air-to-water heat transfer instead of generating heat by electric resistance or burning fuels. As you may have already guessed, these heat pumps only work when the air temperature is higher than the water temperature and not less than 40°-50°F (4°-16°C) range. So it works in hot-to-warm searsons when the air is warm The working principle is simple: the water pump pumps pool water into the heat pump. So the water drawn from the pool passes through a filter first then enters the heat pump heater. To heat the pool water the heat pump first employs its fan to pull in the ambient air and blows on the evaporator. The warm air gets the liquid refrigerant to its boiling temperture and it turns into a warm gas. The gas then passes through the compressor where its temperature rises. The hot gas now flows into to condenser where a heat exchange happens between the refrigerant and the pool water. The cooled refrigerant becomes liquid again and returns to the evaporator where the cycle repeats. The heated water then returns to the pool through the heat pump'a water outlet.

Heat Pump Water Heater VS Fuel-Based Heaters

While considering heating solutions for your swimming pool natural question may arise as to what type of heater is preferable. The available options are the conventional propane or natural gas heaters, solar pool heaters, or heat pump heaters. Here we will list the pros and cons of fuel-based versus heat pump heaters. In either case, covering your pool with a solar cover will inhibit the evaporation and help you preserve the heat within the pool.

Fuel-Based Heater

Pros Cons
Less upfront investment higher operating costs
Works in any temperature higher carbon emissions
Fewer mechanical components Dependant on fuel prices
Heats the pool quickly

Heat Pump Pool Heater

Pros Cons
Low operating costs More expensive upfront
Environmentally friendy Only works in temperatures above then 40°-50°F
Doesn't require gas pipeline
Longer lifespan

Heat Pump Pool Heater Sizing

Accurately sizing a heat pump heater for your pool would require a seasoned pro because of the many factors going into consideration. The basic factors that come into play are

  • pool area
  • ambient air and pool water temperature difference
  • wind exposure 
  • humidity level
  • temperature drop at night

So, just to give you a sense about how this factors interact consider a pool in an area where winds are rapid, the air humidty is low, and the temperature drop significantly at nigtht. In this case, a larger sized heat pump is needed as apposed to an area with calm winds, higher humidity, and warmer nights.

You can also do a small rule-of-thumb calculation for using the following formula:

Pool area x Temperature Rise x 12

where Temperature Rise is the temperature difference between the desired pool temperature and the average temperature of the coldest month when the pool is still going to be used. For example, 200 sq f x 20°F x 12 = 48k BTU. So you should pick a heat pump that has rated BTU output nearest to the value we calculated.

Best Heat Pump Pool Heaters

Fibropool Swimming Pool Heat Pump

Fibropool FH-220

Main Features:
  • 20k BTU/h heating capacity
  • Suitable for pools up to 7.5k gal in coastal climates 
  • Suitable for Hot Tubes
  • Weighs 100 lbs (45 kg)
  • Width x Length: 36" x 16" (91 cm x 41 cm)
  • 240 V; 60 Hz

This is a compact and lightweight heat pump for small pools and spas. Suitable for pools up to 18 ft round and spas of any size. Works in both heating and cooling modes. The package includes union connectors and hose adapters for 1 1/2" PVC plumbing. Adapters work with 1 1/2" and 1 1/4" hoses. Operating temperature range is 40°F - 93°F (4°C - 34°C)

Pros Cons
Works quietly The pipe adaptors are not of a common US size

Easy to install

Titanium heat exchanger

Hayward HeatPro Titanium 50k BTU Heat Pump

Hayward HP50TA

Main Features:
  • Corrosion-resistant evaporator fin
  • Titanium heat exchanger
  • UV-resistant body panels are impervious to rust
  • CPVC union plumping connections

Hayward heat pump is equipped with acoustic compressor cover and profiled fan blade to ensure quiet operation. Thanks to its round design it easily fits through gates and takes up less space on eqipment pad. Durable injection-molded casing is rustproof and immune to deterioration. The hardware is made of stainless steel with polyethylene screen to protect the evaporator coil from damage. 

Pros Cons
Shuts off when reaches preset temp Drips water around its body
Clear manual Union nuts missing for assembly
Quiet and economical Customer service

Pentair Ultratemp 110 Pool Heat Pump, Heat Only

Pentair Ultratemp

Main Features:
  • 230V, 60Hz, 50A breaker size
  • Titanium heat exchanger
  • Automatic defrost feature
  • Corrosion-resistant plastic composite cabinet
  • Dimensions (LWH): 43" x 34" x 50"

This pool heat pump is a bit on pricey side. It has an LCD control board display with intuitive menu items. AutoSet feature monitors the water temperature and turns the water pump on and off as needed to maintain desired water temperature. The corrosion-resistant case stands to severe climate conditions so it's waterproof and long-lasting. Lastly, BTU output and COP (coefficient of performance) have been independently certified by AHRI. Comes with 2" plumbing connections for easy installation. Compatible with IntelliTouch and EasyTouch centralized control systems. 

Pros Cons
Timer override - shuts off when not heating Expensive
Bright display; clear control settings
Runs quietly