Heat Pump Calculator
Statements of heater/heat pump performance are based on estimates. Actual performance may vary and is not guaranteed. Estimates for heat-up time and temperatures are based on operation in a controlled environment. Real-world operational results may vary due to various factors and variables, including, but not limited to, environmental conditions, geography, elevation, seasonality, weather, wind, sun exposure, humidity, precipitation. Other factors of the pool that may impact heating performance include design and configuration, volume/size, orientation, R-value of construction materials, plumbing length/materials, operating conditions and more. Pentair recommends consulting a pool professional for assistance with heater/heat pump sizing for specific locations and environmental/operational conditions.
All statements of savings are estimates compared to a gas heater operating under the same parameters used in heat pump estimations and inputs made by the user. Actual savings may vary and are not guaranteed. All utility rates are estimates for the user selected location and are not guaranteed to be accurate. Users should adjust utility rates to known rates for their local area if known to improve estimation accuracy.
What Size Heat Pump Do I Need For My Pool?
What Size Heat Pump Do I Need For My Pool?
Here you are on the Costa Blanca, Spain, new home and hopefully a new pool. When you moved in, you imagined late summer nights enjoying a glass of your favorite vino tinto and taking a relaxing dip overlooking Javea, Denia, Moraira or any number of small paradises here on the Costa Blanca, Spain.
Soon the summer ends and there may be some nice fall days warm enough to use the pool, but eventually temperatures begin to drop. You are pressed with two choices: wait for the temperature to warm up again and heat the pool naturally or, look for an affordable pool heater.
If you take the first choice and wait, the truth is you will not be using your pool all year. But, if you decide to buy a pool heater, then we are here to help you make the most informed choice. Firstly, we have to recommend buying a heat pump pool heater. They offer the best value for money and are capable of getting the job done correctly.
If you take our advice or you do a bit of research on your own, you will surely ask next: “What size heat pump do I need for my pool?”. In this article, we will go over the basics so that you can make an informed choice and really understand what kind of financial commitment it will take to heat your pool. The answer may be well under what you think!
What is a Heat Pump Pool Heater?
Heat pump pool heaters work almost like a reverse air-conditioner. Instead of exchanging warm air for cold air, they put all of that heat generated in the process into the pool’s water.
Unlike an air conditioner, pool heaters do not need to work so hard for instant results. They implore a slow and steady technique that draws less power and costs you less money. For this reason, heat pumps have the highest coefficient of performance or COP rating of all types of pool heaters. Want proof? Every hotel that has a heated pool uses a heat pump to save on their pool heating efforts.
A study done by the U.S. Department of Energy on pool heaters ultimately recommends using heat pumps as they perform the best and draw less power. After the study was published, the number of heat pump pool heaters sold in Florida alone grew by a staggering 480% year over year. Hotel chains rushed in to save thousands per year on pool heating.
Why Is Pool Heat Pump Sizing Important?
Pool heat pumps run on electricity. Now that can be either from Ibidrola or from a solar panel installation. Because heat pumps use electricity, they heat pools slower than a gas heater.
Heat pump sizes and capabilities are measured in BTUs or British Thermal Units. BTUs are a measurement of heat and thus used to calculate a pool heater’s abilities. Generally, pool heaters’ BTU ratings start at 50,000 and go up to 150,000. For smaller pools or pools above ground, you may be able to use a unit of 50,000. Bigger pools will require something bigger naturally.
A quick tip, when buying a pool heater you should always pick a unit that is slightly over the required number of BTUs. This will do a couple of favors for you.
1. It will heat your pool faster than a smaller unit.
2. A larger pool heater will work less hard and more efficiently.
3. Save you money in the long run due to less operating time.
With that being said, there are some other factors you should consider when buying a heat pump pool heater. Let’s get into them now.
How To Size A Pool Heat Pump
Factors like the size of your pool, the average air temperature, humidity level and how windy it is where you live make a difference in your pool heating efforts.
If you correctly size your heat pump, those outside factors will play less of a role in getting your water temps up and keeping them there.
Here are two ways to size up the correct heat pump for your pool:
The Easy Way To Size a Heat Pump
In our chart below, we show you the general amount of BTUs you need from a heat pump. This makes it easier for you to estimate what you need to heat your pool.
Based on this table, if you had a 60,000 litre pool but wanted to buy a 120,000 BTU heat pump you would be making a wise choice. Your pool water will be heated much faster and with less operating time on the pool heater.
Sizing Considerations
If you are still having doubts, here are some questions to consider:
How quickly do you need to heat your pool?
- The BTU output of a heat pump ranges from 50,000 and up. The higher the number of BTUs, the faster your pool will heat. If you use a conservative heat pump size, your pool will heat more slowly than with a larger unit.
What is your desired water temperature?
-
Most pool owners want their water to be between 27ºC and 30ºC. A smaller heat pump may not have the energy needed to reach the preferred temperature. You can always ask one of our pool heating experts here at Tropical Energy Solutions for a proper size considering temperature.
Other Pool Heating Considerations
With a heat pump pool heater, maintaining your water temps will reduce the amount of electricity that you will use. Here are some recommendations:
How often do you use the pool?
- You should aim to only leave your pool uncovered a maximum of 2 hours per day. If you are using your pool for more than 2 hours consider that you will be losing heat and will need to keep your pool heater on a bit longer.
What months do you use your pool?
-
Heat pumps work best in warmer temperatures, so lucky for us here in Spain a heat pump will work perfect all year round. Keep in mind that if you are using your pool in January or February, you will need to run the pool heater for about a week or 10 days to bring that water temp up to a swimmable level.
How much are you willing to pay?
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Heat pumps are a much cheaper option than a gas pool heater. We’ve found that they are half the price at least. But heat pumps do cost a bit more up front. The savings in the long run make gas pool heaters a very expensive option when compared to a heat pump.
Pool Heating: How to calculate pool heat pump sizes
Pool Heating Pump Systems: how to calculate heat loss and heater size
This Blog post goes in a bit of detail the complex calculations we provide for you with our instant online pool heater calculator.
This report is the gold standard of pool heater sizing and heating evaluation and will provide you with all you need to know to get your pool heated.
Continuing from last weeks post where I explained how pool heat pumps being the most efficient way of heating a pool, I mention to speak to experts on how to calculate the heating requirement. This week I delve a little deeper into the technical aspects of pool heating pump Explaining COP, heat up times and kW required. So put your thinking cap on and continue reading, maybe you'll be an expert by the end.
What is a COP
What does COP stand for? You probably read this quite often on the sides of pool heat pumps and typical air conditioning systems. While conventional heaters only achieve efficiencies of about 75%, a heat pump delivers on average about 5 times the heat absorbed. Nearly 80% of the energy needed to heat the pool comes from the ambient air. With the newest inverter models this efficiency can be up to a COP of 15 depending on humidity and temperature.
A COP is in direct relationship with ambient air temperature and humidity because a heat pump extracts the heat from the air. Here is an Example of a COP chart taken directly from our testing facility of the Elite 11kW
For example, with a COP of 5 - 1kW of electricity consumed, creates 5kW of heat released into the pool.
In an example, if we warm our 40m³ pool by 10 ° C with a running time of 40 hours . For this we need a heat pump with an output of approx. 13.94 kW.
A heat pump should have about 1/5 lower power consumption = 13.94 ÷ 5 = 2.79 kW input
The relationship between the power supplied by the heat pump to the pool and the power it consumes is determined by means of the so-called COP factor (power coefficient). The higher the COP value of the pump, the more powerful it is and the lower your electricity bill.
Photovoltaic solar systems
are increasingly being installed in the private sector in order to achieve an even more cost-effective power supply. Anyone who has such a system can use a heat pump very economically.
How big does the heat pump for my pool have to be?
If you use your heat pump directly through your filter system, you should adjust the kW output to be slightly higher for lower run times but as an example here is a guide.
pool size
kW power heat pump
30 - 40m³
min 9 kW power
40 - 60m³
min 12 kW power
50 - 80m³
min 16 kW power
The heat pump should be able to heat the water by approx. 0.20 - 0.25 degrees per hour. It takes 1.16 Wh to heat one litre of water one degree, which means 11.6 kWh for a 10m³ pool. In other words, one kilowatt hour heats 862 litre of water by one degree Celsius.
The following table shows how the heat pump is best designed:
volume
Temperature increase per hour at a power of
m³
8 KW
12 kW
18 kW
25 kW
36 kW
10
0.58
0.89
1.33
1.96
2.64
20
0.28
0.45
0.65
0.98
1.31
30
0.21
0.28
0.45
0.67
0.89
40
0.16
0.23
0.34
0.48
0.67
50
0.13
0.19
0.27
0.38
0.54
60
0.11
0.15
0.21
0.33
0.45
70
0.08
0.13
0.19
0.28
0.38
80
0.07
0.11
0.16
0.25
0.33
90
0.07
0.10
0.15
0.22
0.29
100
0.06
0.09
0.13
0.20
0.26
120
0.05
0.07
0.11
0.16
0.22
Choosing the right pool heat pump for your pool size?
The performance data is based on the following calculation basis
C x VX (T2 - T1)
P = -------------------------
h
P Performance of swimming pool heat pump
C heat storage coefficient of water = 4.186
V Pool volume
T2 Set temperature
T1 Start temperature
H Heat up time
The maximum heating time should be 4 hours per 1 ° C water temperature. This is calculated by the heat loss during the night being up to 2°C meaning it would take 8 hours to heat up to full temperature maintaining a constant temp throughout the season.
Example:
Say you have a swimming pool with 40m³ of water and an initial temperature of 18 ° C.
You want to heat the water to 28 ° C. The maximum heating time should be 4 hours per 1 ° C water temperature. Consequently, it takes 40 hours to heat up your 40m³ pool by 10 ° C.
This results in the following formula:
4.186 x 40 x (28 - 18)
P = ------------------------ = 52.33kW
40
What else do you need to know about a heat pump?
The choice of location is also very important because the heat pump needs very large amounts of air to function properly! For this, a suitable place for the fresh air must be found in most cases indoor operation does not work.
The heat pump itself is then integrated directly into the filter circuit, after the filter system and before the chlorinator if fitted.
High-quality heat pumps are equipped with corrosion-protected heat exchangers and can thus heat any swimming pool water, whether it is cared for with chlorine, bromine, ozone or chlorine-free products. The use for pools with sea water is also possible.
With all pools other factors including solar gains, wind factors and evaporation losses need to be taken into consideration. This article is to give a bit of insight on one way of sizing.
