We're doing a massive pool rehab and have a couple questions

Apr 21, 2017
12
Pass Christian ms
I'm new to pools and to spas, First off the pool has an inground spillover spa that had a heater at one time but now none of the related heating items are present. Spa is basically half of an octagon. Approximately 5/7. I'm in southern ms. During the summer the average temp here is 90 at night it's usually in the 70s my question is will a 5.5 letter heater work for this hot tub I have a system from an older above ground spa I was contemplating using but it might not be worth the trouble. Says it's a pinnacle. Anyway any info is appreciated.
 
Is that a 5.5 kWh heater? It won't work very well for an inground spa. They are designed to maintain continuous heat for an insulated and covered hot tub. Heating up concrete and the ground around it will take forever and it will have to run a lot to maintain the heat.
 
If you want to be able to let it sit at ambient temp and heat on demand then at least a 250k btu gas heater, 400k btu is better. By the way, a 5.5kw heater is a little under 19k btu.

If gas isn't an option you can use a 140k btu heat pump but it will take longer. You might want to cover it and keep it partially heated to speed heat up, say 85 or 90 degrees.
 
2545 btu/kw so 5.5 kw heater would equal approx. 14,000 btu. Substantially smaller than recommended

My bad, the conversion above is to hp not kw. 3411 btu/kw so about 19 K btu as mentioned above (long time ago when I was a practicing engineer I had all these conversions memorized)
 
Big as possible if you want to heat it fast. I'd avoid electric for an inground spa. The bigger one will heat faster and be able to keep up with demand as cold air is pulled in through the jets for your bubbles.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.