I just purchased a home with a 65,000 indoor pool.

I am wondering how many BTUs I will need to heat the pool comfortably.

Thanks for the question

It's difficult to say with a degree of accuracy how many BTUs you'll need because I don't know the shape of the pool. The square footage is needed but I can give you the calculations.

You need to know the desired temperature for the pool

Average temperature for the coldest month of pool use

Next, you need to know the temperature rise needed. You'll subtract the average temperature from the coldest month FROM the desired pool temperature.

Now you need to know the surface area for the pool

The calculation is:

Pool area x temperature rise x 12

Rectangular - L X W

Round - 3.14 X (Diameter/2) x (Diameter/2)

Kidney - .45 X (A + B) L

For a kidney shaped pool, the "A" is the width in the shallow end and "B" is the width in the deep end, or the widest point.

I'll do a simple dry run.

Let's say you have a rectangle pool. Length is 50' and width is 15'. L x W = 750 sq. ft.

Desired pool temp. is 80 degrees.

Coldest average month is 60 degrees. 80 - 60 = 20 degrees. This is the temperature rise.

Pool surface area is 750 sq. ft.

So it's 750 x 20 x 12 = 180,000 BTUs.

Remember to go a little bit over, say about 200,000 BTUs. It's easy to dial it down than have it constantly running.