Due to covid-19 all indoor pools in my area are closed for the foreseeable future. Kids being swimmers, I purchased an Intex 15' round above ground pool and installed in it in the garage. It worked well over the summer, but I would like to turn this into a year around solution, at least through this winter. Since I hope this is only for one season, I am not looking into a full blown pool heating system and am trying to keep this on a budget.
I am considering using a tankless, on-demand water heaters running on LP to heat the pool and am looking for pointers why this won't work or is a bad idea. Taking one manufacturer, it seems that specialized pool heaters are double the price of a water heater. I am trying to keep my initial outlay to ~ $1,000, but also wonder how much it will cost to heat. Water Heater: https://www.rheem.com/group/rheem-tankless-mid-efficiency-tankless-mid-efficiency-64-direct-vent-indoor VS Pool heater: https://www.rheem.com/group/rheem-residential-pool-spa-heaters-above-ground-pool-spa-heaters-106
Some info: Pool Size: 5,000 gallons. Garage is cinderblock construction with roof, but no insulation anywhere. We are in the Washington, DC area so avg winters are hovering in low 30s overnight. Pool currently has a 320 GPH pump.
Also, how to ballpark estimate the cost of heating:
Assuming an initially cold pool at 50 degrees, at 6GPM and 35 degree rise, I can circulate all water in the pool in 11 hours, and get the pool to 85 degrees. (78 is enough for swim practice). Now all the heat loss starts and I need to keep water circulating, to keep it as 78 degrees. How much LP would I be burning through on a daily basis?
Updates based on questions asked:
- Pool is a single layer vinyl and comes with a cover.
- With valid points raised about 1) heat loss and 2) condensation, sounds like insulating the garage is a must.
- Currently considering R10 rigid foam for all walls, both Owens Corning FOAMULAR and Thermasheath Rmax seem water resistant, so this feels OK.
- Not sure what is best for the roof. Should can cut the same boards and add in between rafters. Or will batt insulation work if protected from condensation, perhaps with a layer of Reflectix bubble insulation on top of batt, facing the inside.