<\/span><\/h2>\nIt is essential to bear in mind that calculating a few elements of pool heater sizes will not give a precise result. There are multiple variables like changing wind velocities and pool surface area that affect the size.<\/p>\n
A pool heater has to overcome the constant heat loss first to begin maintaining a consistent pool temperature. Here are a few factors that will help you make an informed decision when sizing your pool heater.<\/p>\n
Pool Volume<\/h3>\n
For straight-walled pools, the general formula in feet goes as follows.<\/p>\n
Average length x Average width x Average depth x 7.5<\/p>\n
For a no-constraint pool with free-form or slanting walls, the general formula is as such.<\/p>\n
Average length x Average width x Average depth x 7<\/p>\n
<\/p>\n
Acceptable water temperature<\/h3>\n
No matter what the purpose of your pool, whether for leisure or training, it requires a comfortable temperature in which to swim. Determine what water temperature is needed in Fahrenheit to get a suitable size of a pool heater.<\/p>\n
Hot tubs or spas attached to the swimming pool would require higher temperature considerations.<\/p>\n
Surrounding air temperature<\/h3>\n
If you reside in warmer regions, the pool heater would not require much BTU to heat the pool. In colder areas, the pool heater would have to overcome the surrounding air temperatures plus heating the cold water, thereby, requiring a higher BTU. Also, if you need the heater to maintain the heat, it would add to the total BTU measurement.<\/p>\n
<\/span>An example to relate to<\/span><\/h2>\nEvery individual pool will have unique conditions that the pool heater has to face. Here is an example you can use as a reference that includes the various pool heater sizing considerations.<\/p>\n
The pool dimensions are 16 inches in length x 32 inches in width x 5 inches of depth.<\/p>\n
The approximate pool volume would get rounded to 20,000 gallons. Also, we assume that the acceptable pool temperature that the owner likes to swim in is 80\u00b0 Fahrenheit.<\/p>\n
To calculate the BTU required, we first convert 20,000 gallons into pounds or lbs.<\/p>\n
The water constant is 8.3 lbs. for every gallon of water.<\/p>\n
So, 20,000 gallons = 20,000 x 8.3, which will give us 166,000 lbs. of water.<\/p>\n
Here, to raise the temperature of 166,000 lbs. water, we need 166,000 BTU of energy. (Since it takes one BTU to heat one pound of water by one degree Fahrenheit)<\/p>\n
<\/span>Next, we calculate the temperature differential.<\/span><\/h2>\nThe ideal water temperature that the owner requires is 80\u00b0 Fahrenheit. In calculating the surrounding air temperature, we assume the worst-case scenario and set the temperature to 50\u00b0 Fahrenheit.<\/p>\n
Hence, the pool heater would have to raise the water temperature from 50\u00b0 Fahrenheit to 80\u00b0 Fahrenheit.<\/p>\n
<\/span>Then comes calculating the time required to heat the water.<\/span><\/h2>\n<\/p>\n
We know that the temperature difference is 30\u00b0 Fahrenheit that the heater must overcome. Once again, we assume a 24-hour window in which the heater must\/can heat the water.<\/p>\n
Here, the 24-hour bracket is merely for reference purposes. You could employ a smaller pool heater for the task and get it to heat the water. Only, it will take longer than the 24-hour time frame.<\/p>\n
Now, to heat the 20,000 gallons\/166,000 lbs. of water with a temperature gradient of 30\u00b0 Fahrenheit, the amount of BTU required would be,<\/p>\n
166,000 x 30 = 4,980,000 BTU<\/p>\n
To gain a BTU\/hour value, we divide the 4,980,000 BTU\/24 hours to get,<\/p>\n
4,980,000 \/ 24 = 207,500 BTU\/hour<\/p>\n
In the end, you would require a pool heater of a minimum of 207,500 BTU to heat a 20,000-gallon pool from 50\u00b0 Fahrenheit to 80\u00b0 Fahrenheit within 24 hours.<\/p>\n
This value is not an exact reference since we made many assumptions to suit the example. In reality, you would not generally require the pool heating facility to meet the given temperature measurements.<\/p>\n