Pool Heating Pump Systems: how to calculate heat loss and heater size
If you are looking for more details, kindly visit swimming pool heat pump size calculator.
This Blog post goes into quite a bit of detail in order to answer the complexities involved with calculating the right pool heater size for your pool. Madimack have an instant calculator which exports a consolidated personalised report detailing your pool heating requirements - It is an instant online and will save you reading the detail (and I won't even know you've skipped my in-depth explanations) pool heater calculator but for those of you (like me) who like the detail, read on!
Don't get me wrong, the report generated by pool heat pump size calculator is the gold standard of pool heater sizing and heating evaluations and will provide in depth detail on all you need to know to get your pool heated. It is used by pool owners and pool service technicians alike to ensure the pool heater installed is the one best suited. The online form takes 3mins to complete and the report is generated and emailed instantly.
Refer to our former posts to find out how and why pool heat pumps are the most efficient way of heating a pool. Or engage with an expert from Madimack's local dealer finder to discuss your options. This article delves 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
For more information, please visit should heat pumps run constantly.
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.
What Size Swimming Pool Heat Pump Do I Need?
Heat pumps offer one of the most cost-effective and energy-efficient methods of heating your pool water, ensuring you can enjoy the swimming season for longer and with reduced heating bills!
To get the most out of your swimming pool heat pump, you must be sure it is sized correctly. Follow our top sizing tips to equip your pool with the right heat pump.
What Factors Affect Pool Heat Pump Sizing?
When we talk about sizing for heat pumps, we typically don&#;t mean the physical size of the unit but rather the energy output.
There are a couple of things you&#;ll need to consider when working out what size heat pump is most suitable for your pool.
- The size of the pool: A larger pool with more water to heat will require a bigger, more powerful heat pump.
- The climate and average air temperature: Air source heat pumps draw heat from ambient air temperature, so if you live somewhere colder, your heat pump will have to work harder to get your water up to the desired temperature (e.g. 28°C).
- Your swimming habits and the frequency of use: If you want to use a heat pump all year round, you may require a larger one that can provide consistent temperature in the colder months.
- The type of swimming pool: Indoor and outdoor pools, as well as in-ground or above-ground pools, will have different heating requirements.
How Does Pool Volume Affect Heat Pump Size?
The size of your pool is the most obvious and easily measured factor that&#;ll determine the necessary heat pump size. The more water a pool contains, the greater the energy requirements to heat all the water.
How to Calculate the Pool's Volume
When you size a pool heat pump, you will need to know the pool&#;s volume.
The average outdoor inground pool in the UK is around 10m x 5m with an average depth of 1.5m. Using these figures, a standard swimming pool would have a volume of around 75m3.
To work out the volume of your pool, please use our swimming pool volume calculator.
How Does Climate Affect Heat Pump Size?
If you live in a colder climate, then your heat pump will need to work much harder to increase your water temperature. This is because they rely on ambient air temperature to transfer heat into the water via a heat exchanger.
Air source heat pumps will continue working in cold weather but will become slightly less efficient. If you want to use a heat pump during the extended season from April to November, a larger, more powerful unit will probably be more appropriate.
Aqua Inverter Turbo-Pro Silence Heat Pumps can operate in air temperatures as low as -15&#; and are available in various sizes to correspond with your pool volume.
How Do Swimming Habits Affect Heat Pump Size?
Swimming habits have less of a direct impact on pool heat pump sizing but you may still need to factor it in.
As the technology is so efficient, a standard-sized heat pump for your pool size should be sufficiently robust and reliable, providing the right level of heating throughout the swimming season.
How to Calculate The Ideal Pool Heat Pump Size
The heating capacity of your heat pump is measured in kilowatts (kW). The more powerful the heat pump, the quicker it&#;ll be able to heat up a pool and the more suitable it&#;ll be for higher-volume pools.
Pool Heat Pump Sizing Calculator
Please note that the below table provides a rough guide only, as the factors mentioned above may have a significant impact on how large you need the heat pump to be. Different heat pumps also have varying coefficients of performance (COP), meaning specific models have different power needs.
We would recommend finding a heat pump model with all the features that suit your needs and then checking the manufacturer&#;s notes to determine which size you may require. All of our heat pumps come with handy tables for you to refer to.
As a basic guide to help steer you in what to look for, here are some averages from across our pool heat pump range.
Pool volume (m3)
Heating capacity in cold air (15C)
Heating capacity in warm air (26C)
20-40
6kW
8kW
40-60
9.5kW
13kW
60-80
15kW
25kW
80-100
18kW
30kW
Should I Oversize My Pool Heat Pump?
Our different heat pumps range from 3.5kW to 32kW.
If you&#;ve looked around at various heat pump calculators and the recommendations for your pool hover between a few sizes, it usually pays to size up rather than down.
The more powerful the heat pump, the quicker it&#;ll heat up your water &#; and once it&#;s up to the desired temperature, it only requires a little bit of energy to maintain. Larger heat pumps tend to have higher coefficients of performance (you get more heat out than energy that goes in), so may be more efficient than smaller units.
Balance this thinking against the size and specs of your pool though, as you won&#;t need the largest possible heat pump for a smaller than average pool or one that has good levels of insulation and measures against heat loss!
To find out more about choosing the perfect heat pump for your pool, check out our advice guide.
If you have any questions about our heat pumps and which one is right for you, please get in touch with the 1st Direct Pools team on 900 .
The company is the world’s best high temperature hot water system supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.