Best Heating Method (Community Pool)

[jrenfro]

We are currently looking at replacing a broken spa heater with a Hayward 250,000 BTU Gas Spa Heater (but someone mentioned the pool and spa were heated at one time) for the community pool and the HOA asked for input from the community. They received a quote for the above option but I thought there must be a better alternative as we live in Arizona that uses a mix of solar and an electric heater. The goal would be to heat the spa for sure at the lowest cost possible utilizing solar and an electric heater with the possibility of heating the pool just slightly during the summer. The spa gets used year round but the pool is still very chilly even with us hitting 100+ degrees already. We have no option for a cover of any kind and I believe the pool is somewhere between (or around) 10x16 or 12x24 with it going from 3ft to 5ft depth (rectangular pool). The spa is in the corner of the pool and is probably 6ft in diameter.

My thoughts would be using the solar to heat the spa water (and potentially the pool water) during the day as we have a restroom building next to the pool and use the electric heater to augment the temperature as needed. Currently I believe they estimated the spa costing the HOA $800/month using the old gas heater and the new unit should be more efficient but there is still going to be loss in heat using gas. Any ideas? First time posting as well so go easy on me!

 

[Isaac-1]

Solar plus other heat source may be your best bet here, although in your climate Solar alone could provide enough heat to comfortably heat the pool, the problem would be night time spa use which would probably need some other heat source to maintain the heat the solar could add to the water during the day.

Ike

 

[Bama Rambler]

Is this an indoor or outdoor pool/spa? (I suspect outdoor but don't want to guess)

With a pool that size you could easily heat it with solar, and probably the spa too. I agree with Isaac that you should go with 100% to 150% solar coverage and then add a second heat source for times the spa needs heating that the solar isn't on.

In your area, taking the solar into account I'd even recommend a heat pump.

Is there any automation on the pool and spa? you could have the solar keep the spa heated and let it overflow into the pool to help warm it up some and then you'd only have to use the second heat source on rare occassions. Even in the winter you can get a lot of heat out of a large solar setup.

 

[jrenfro]

Do you guys have an recommendations for type of equipment to accomplish this? I would like to bring a good proposal to the HOA in regards to this project and have them take it to their pool guy for a quote. It is indeed an outdoor pool and I have included a picture from Google Maps. You can see we have a small building south of the pool with restrooms where we can place solar panels probably on all 4 sides of the roof as it gets good sunlight from early afternoon until 4-5pm.

I found these as far as solar heating goes but what would you recommend for an electric heater or heat pump (and really what are the differences?). I am sure the pool guys will have the brands they prefer but I want to at least bring the right equipment to their attention for the quotes.

Also the spa does not overflow into the pool at all but that would not be a bad idea if they do future renovations on the pool. Thanks again for all the input you guys!

 

[Bama Rambler]

If that pool is 12' x 24' pool, then that building is pretty small and I don't think you could even get one panel on each roof section. Is there a nearby roof that panels could be installed on?

Since the spa doesn't overflow into the pool I assume you have two distinct equipment systems. If that's the case you'll need some automation system to switch the heat sources between the two. I'm sure there are automation systems that can do it I don't know off the top of my head which would be best suited for it. The Pentair Intellitouch system could do it, and I'm sure several others can too.

You don't want resistance electric heat. You either want a gas heater or a heat pump. Rheem seems to be highly thought of, but there are lots of brands out there.

 

[ps0303]

In a commercial pool/spa setting, usually the pool and spa are separate and have their own pumps. What you are going to need are two separate heating sources to properly heat both bodies of water. You can go solar and/or heat pump for the pool, but I would highly recommend a gas heater for the spa. With a spa you want the water warm enough 24 hours a day for your people. A gas heater would be on all the time and only actually running when the water temp gets below your set point on the heater. Solar and a heat pump are not going to be able to heat your spa, especially at night and during your cooler months.

Be careful on the efficiency ratings listed on pool heaters. You will pay a much higher price that actually may not be worth the effort.

As for looking into over flowing your spa into the pool, you don't usually want to do this in a commercial setting. Spa's generally get lots of use and since they are a smaller body of water you have to maintain chemicals a bit different. Your health department can provide you with the specs for your area. I'm sure all health departments pretty much run with similar codes for commercial spa's.

Generally you usually dump the spa water once or more per week depending on bather load, use. This has to do with the TDS (total dissolved solids) in the water. Once they get to a certain level you can only properly lower them by emptying the water either all or partially and then refilling with fresh water. This is the only way to have a healthy spa. Maybe you already know this stuff. Just providing you with as much info as possible.

So, stick with gas for the spa, makes for happy customers. Look into solar and heat pump combo for the pool.