In this video, I will look at what size heater you need for your pool, spa or hot tub. I will explain that there are no hard and fast rules here as far as size is concerned, but it is more about your own personal usage and what you are looking to do in terms of the temperature.
Size Calculator can be found here - buildahottub.com/heater-size-...
Too small of a heater and it will take too long. Too big, then you will be over spending on the intial purchase.
How does the Pool and Hot Tub Calculator Work?
In order to calculate the heat needed to raise the temperature of the pool or hot tub then we need to convert the volume into a physical weight.
To determine the weight of water in your pool, multiply the number of gallons by 8.34. This gives you the weight in pounds.
Next, divide the weight of water by the BTU size of your heater to find the time required to increase the temperature by one degree Fahrenheit.
To find the total time required to raise the temperature by a specific number of degrees, multiply the desired temperature increase by the time it takes to raise it by one degree.
For instance, suppose you have a 20,000-gallon pool and a 200,000 BTU heater.
Multiply 20,000 by 8.34 to obtain 166,800 pounds of water.
Divide 166,800 pounds by 200,000 BTUs to get 0.834 hours per degree F
If you wish to increase the pool temperature by 10 degrees, multiply 10 degrees by 0.834 hours per degree, resulting in 8.34 hours.
Pretty straight forward, but the calculator below will do this for you so just input the variables that you need.