Pool heat pump

Table of Contents


A heat pump is a device that uses a small amount of energy to move heat from one location to another. Heat pumps used for heating pools transfer heat from the outdoors into the water. Because they use heat that is already available and just move it from one place to another, they use less electricity.

How to work?

  • Water flows to the poolheat pump
  • Air is sucked into the poolheat pump
  • Heat is extracted from the air
  • Refrigerant is heated to a warm vapor
  • Refrigerant vapor is pressurized into a hot gas
  • The hot refrigerant flows through a heat exchanger
  • Pool water gets heated in the heat exchanger
  • Cold refrigerant and warm water flow out of the heat exchanger
  • The cold refrigerant flows to the expansion valve
  • The heating process repeats


PoolHeat Pump work diagram


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Unit & Installtion & Running Cost

Pool Heat pumps are priced according to BTUs and COP. Prices start at $2,000 – $3,000 and go as high as $4,000 – $5,000.Heat pump operating costs vary by geographic location, desired pool temperature, and whether or not a pool cover is used. DOE estimates that keeping an outdoor pool in Miami at 80 degrees year-round costs $1,460 for an uncovered pool and $300 for a covered pool.

Professional installation of a swimming pool heat pump is recommended and might cost $400 – $500 depending on the complexity of the installation. Heat pumps require a dedicated breaker and most of the installation work is electrical, so it makes sense to hire an electrician (or qualified pool professional) for the job. Additional costs include an annual tune-up and any required service or repairs. Consult the heat pump owner’s manual for a recommended maintenance schedule.

How much does it cost to heat a pool with gas?

The average cost to heat a pool for one hour on natural gas is around $ 7.00. To heat, an average pool (10-12K Gallon) with no solar cover typically takes 8-14 hours.

Annual operating costs depend on the type of heater, local energy rates, the size of the pool, the temperature you maintain, local climate, the length of the swimming season and more. This energy department guide offers estimates of what you can expect to pay for gas heat in various U.S. cities. Annual costs range from $100 to $3,600.

Electric pool heater running cost

Heat pumps will use around 5,000 watts or 5 kilowatts per hour per 100,000 BTU’s. For a typical size 100,000 BTU heat pump, that’s 5 kilowatts per hour. The average for electricity in our area runs $. 16 cents per kilowatt hour, $175 to $600 cost per month.


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Pool heat pump sizing

  • Sizing Considerations
  • How quickly do you need to heat the water? The BTU output of heat pumps ranges anywhere from 50,000 up to 150,000. The higher the level of output, the faster your pool will heat up. If you decide on a middle of the road output like 100,000 BTUs, it will still heat the pool, but it will also take longer.
  • Do you have the required electrical? Heat pumps require lots of electricity to run and is one of their main drawbacks, as this can put a sizable dent in your wallet (although they’re still cheaper to run than gas heaters). You should also make sure that you have the proper electrical setup as heat pumps require anywhere from 50 to 60 amps to power.
  • What is your desired water temperature? Most pool owners want warm water between 82°F and 86°F. With heat pumps, they can only generate so much heat and will eventually top out (especially smaller pumps) due to their dependence on the outside temperature for the level of BTU output. Generally, though, you should be able to heat your pool to 82°F on warm days.

Size A Pool Heat Pump

The Easy Way

The chart below shows the general amount of BTUs needed when using a heat pump. This makes it easy to choose a pump that will work with the amount of water in your pool.

Pool Volume(Gallons) Heat Output(BTU)
10000 50,000 BTU
15000 90,000 BTU
20000 120,000 BTU
25000 140,000 BTU

Based on this information, if your pool has 15,000 gallons of water, and you wanted to go with a 120,000 BTU heat pump, you absolutely could. It wouldn’t be overkill, but rather it would heat the water in a shorter period of time. 

The Precise Way

If you want to be spot on with your heater size, first you need to determine the required increase for your desired temperature.

For this example, we’ll say the pool is sitting at 65°F and we want it to go up to 80°F – an increase of 15°F.

Secondly, you need to find out the surface area of your pool. We’ll use a 16 x 32-foot pool for an overall square footage of 512.

Now, calculate the appropriate values using the following equation:

(Surface Area) x (Temperature Increase) x 12 = (Minimum BTU Needed)

512 x 15 x 12 = 92,160 BTUs

According to these calculations, you’ll need a heat pump that can output at least 92,160 BTUs to increase the temperature in a 16 x 32 pool by 15°F.

For reference, a 16 x 32 pool is roughly around 15,000 gallons of water.

Looking at the chart above, we can see that 15,000 gallon pools require a heat pump with 90,000 BTUs, which is right in line with our 92,160 BTU figure.

Pool heat pump heating time

Heat pumps and heaters, alike, are sized according to the British Thermal Units (BTU) per hour. One BTU raises one pound of water by 1 degree F. One gallon of water weighs 8.34 pounds. So, 8.34 BTUs raise one gallon of water by 1 degree F.

FORMULA: Determine the time required to increase water temperature by 1 degree F

of gallons in pool X 8.34 = _ lbs. of water

__ pounds of water / BTU Size = The hours it takes to raise the water temperature by 1 degree F


You have a 20,000-gallon pool and use a 125,000 BTU heater. Your water is currently 70 degrees F but you would like it to be a minimum of 80 degrees F. How long will it take before the pool water reaches 80 degrees F?

20,000 x 8.34= 166,800 lbs

166,800/125,000= 1.33 hrs to increase 1 degree

80-70= 10 degree difference

10 x 1.33= 13.34 hours of heating before the pool reaches 80 degrees F.

In most cases, calculations for a heat pump and heater are optimistic. For heat pumps, the efficiency varies depending on the air temperature and therefore the calculations cannot account for cooler temperatures. The listed BTU size is when the air is quite warm.

Gas heaters are more consistent, however, they are also less efficient. They are only about 80% efficient, which needs to be factored in. Also, you can always expect to lose heat overnight, increasing your overall heating time. After using this formula to calculate how long it takes to heat up your pool, it’s always a good idea to round up to account for heat loss and efficiency. The formula gives pool owners rough estimates, not exact times.

Pool heat pump noise

What Is Decibel?

Sound is measured using an instrument that expresses in Decibels. It is abbreviated as dB. The least audible noise is at 0 dB, from there, every increase of 3 dB represents a doubling of sound intensity, or acoustic power. The ambient noise level is 30 dB.

Swimming pool pumps noise

A typical swimming pool pump runs in the range of 65-90 decibels, almost as loud as riding in a subway car. This can be a detriment to a pool’s outdoor pleasure. Even a small decrease in this sound can help tremendously.

Reduce pool heat pump noise

Replace Fan and Motor
If the fan that blows air into your home is damaged or worn out, it can cause you to have a loud unit. Our technicians can replace the condensing fan, fan motor, or blower motors to make your unit run smoothly again. Not only will we replace the unit, but we also inspect the area around the fan for trapped debris and loose screws. Either problem could damage your fan motor and cause it to run loudly.

Install Compressor Sound Blanket Wraps
If an old compressor is causing your heat pump to be louder than usual, you could have technicians come out to install a compressor sound blanket wrap. Made from noise-reduction material, these wraps fit snugly around compressors and minimize the amount of noise they generate. This solution is ideal for units that were manufactured to be loud or are starting to wear out due to age.
As long as the compressor is still functioning properly, using a sound reduction wrap is an effective, cost-efficient solution to the problem. Though it is a fairly simple process, the best idea is to contact the experts at The Heat Pump Store. Our technicians can verify that your compressor is still working correctly and ensure that the wrap is installed snugly and properly so it does not interfere with how the rest of your heat pump works.

Use Vibration Isolation Dampener Mounts
When your compressor vibrates excessively, it causes your heat pump to be noisy. Installing small vibration isolation dampener mounts on the bolts that hold the compressor in place is an easy, effective solution. The experts at The Heat Pump Store can install them quickly to diminish noise while ensuring that your unit is still functioning correctly and does not need further heat pump repair.

Replace the Unit
Having a good heat pump maintenance team helps your unit last a long time, but all units eventually wear out due to age. The average lifespan of a heat pump can be anywhere between 10-15 years depending on the amount of use, and regular maintenance the unit has received. If your compressor or even the entire unit has quit working completely, it is probably time to consider purchasing a new one.
If you decide to replace the noisy heat pump, the technicians at The Heat Pump Store can install a new one quickly and efficiently for an affordable price. It is always a good idea to contact professionals when your heat pump is acting up, and we are experts in the industry. When you want to eliminate heat pump noise, we can determine which part is causing the noise and help you find ways to eliminate it, all while ensuring parts are installed correctly.

Pool heat pump humidity

Most heat pumps are rated at 80°F (27°C) swimming pool water temperature, 80°F (27°C) ambient temperature, and 80% relative humidity. A heat pump’s BTU output may drop by 6%, depending on equipment design, when the relative humidity drops from 80% to 63%.

Yes, it is true that air-source heat pumps operate better in temperatures over 50°F (10°C) and a heat-only swimming pool heat pump can work effectively down to the mid to lower 40°’s. However, a point to remember is that ambient temperature plays a major role when it comes to air-source heat pumps. The colder the air, the less heat your heat pump will be able to produce.

Do pool heat pumps work in high humidity?

Higher humidity levels during the winter can absolutely create issues for your heat pump and your nice warm home. Higher humidity means more moisture passing through the unit. When the air is cold and wet, it makes it harder for your heat pump to heat the air.

Operate pool heat pump

Are pool heat pumps expensive to run?

Heat pumps can cost from $150 – $650 per year to run depending on your application, you can also further reduce these costs by using solar power from energy sourced from the sun, virtually costing you $0 to heat the pool.

How cold is too cold for a pool heat pump?

Most Heat Pumps will work if the temperature dips below 60, but will automatically shut off if the temperature reaches 45 – 50 degrees Fahrenheit. By shutting off automatically, Heat Pumps prevent damage that can occur when the air gets too cold.

How long should a pool heat pump last?

With proper installation and maintenance, a pool heat pump will generally have a lifespan of about ten years, though many have lasted longer. We at AquaCal have seen some last as long as 15 years! So those are some factors that will affect the lifespan of your heat pump.

Where to install pool heat pump?

A pool heat pump’s base should be level or flat irrespective of it is installed above or below water level. You can install the unit on a small section of timber decking or on a concrete base or paving slabs laid on sand.If circumstances allow, stay close to the pool. Shorter pipe runs = less work for the pump which extends the life of the pump and uses less electricity. Our projects typically average a distance of 20–40 feet from the pool to the equipment, but as stated earlier, much longer runs are sometimes required.

Can a pool heat pump be installed indoors?

Generally no. Some pool owners may equate an indoor swimming pool with a heat pump. Although it is a good idea to have a swimming pool indoors, a heat pump won’t work indoors and must remain outside. Heat Pumps work by transferring heat from the surrounding air to the pool water. If a heat pump is installed indoors there must be a continuous supply of warm air from which the heat pump can extract heat. If you must heat the air in the room before the heat pump can extract that heat to heat the pool, there would be no benefit to the heat pump.

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