heater for spa not pool any suggestions?

My husband and I are having a pool constructed for us and the job foreman and gave us a lot to think about. The sales man said that a 11KW heater on the spa would work fine, but the job foreman said that it will take it all day to heat up and expensive to run the electric heater.

Any ideas on what would work best? I know ideally we would like a gas heater but too expensive. We live in SW FLorida so it doesn't get that cold here but still want to heat the spa after a long day at work.

Thanks for all the help!

It's sort of a 'pay me now or pay me later' thing.

In your area of Florida, each time you heat a 400 gallon spa from 80 degrees to 104 degrees (∆24), you'd need around 80,000 BTUs (400 x 8.3 x 24). At 98% efficiency for an electrical heater, or about 24 kilowatt/hours, at about $0.15/kwh effective cost. So, each evening when you came home, you'd be spending $3.60. If you use it 20 times per month, that's $72.00.

Given that the cost of a gas heater is about $700 more than an 11KW heater . . . . well, you'll have to work it out from local gas rates. If you already have natural gas, costs may be only 1/3 of electric heat.

I have one of those 11KW electric heaters and depending on how much you enjoy a warm pool/spa is the key to it's use.

The fine members here who know what they are talking about suggested solar to me. As a test case I got one of the small Game circular solar heaters. In early-mid May, just one barely would keep the pool at the temp it was. I added one more and all was very well and I was able to increase temp by 2-3 degrees a day in roughly 7 to 8 hours of direct sunlight. Now that it's upper 90s to 100 here I have the covers on the solar heaters and figure once it get's below 85 I will uncover them for that nice warm water pool effect.

If I had it to do over I would either make my own solar system with PVC and some sort of box type setup or I would get the large Game circular solar heater and be done with it.

So my final comment is, I like having both. I will try and run my pool on "free" heat for as long as I can, then and only then will I make the decision to turn the electric heater on. And if you are wondering, the electric heater will keep the temperature constant with the outside temp in the mid 60's with everyone in it. I am using this only to extend the use of the pool way later than most "normal" people.......but that is a choice I have made and running the electric heater does cost me.

Bob E.