Solar heating info needed

[cleancloths]

I've got a 20 x 40 IG pool with an electric heatpump in Northern NJ. I have always used a solar cover on the pool which works really well but is a royal pain in the rear. I was thinking about adding a solar heater in addition to the heat pump instead of using the cover. Any idea if a solar sysem with 4 sets of 2' by 10' panels would provide me more or less heat than what I would give up by not using the solar cover?

Any recommendations of what brand and where to get a solar panel system if this makes any sense to do?

Thanks

[tphaggerty]

I have a 20x40 IG in Dutchess (NY, same general weather as you) with solar only. I recently expanded to a 2nd set of roof mounted panels (east facing roof unfortunately) so now I have about 600+ sf of coverage.

I really doubt that the 80sf you are considering is going to do much, unless they are facing directly south and you run them all the time, even then it probably is marginal given the piping and such you will need to do. The solar cover really does its magic at night when evaporative losses can drive the pool temp down 4 degrees or so. Having a pool cover on will reduce that substantially.

For a full rundown on how solar really works, go to powermat.com. There is a really excellent solar installer in your area (solarliving.com), they gave me LOTS of free advice and a good bid, but they deal mainly with permanent systems. I honestly think that once you price out a reasonable solar installation, you will find your solar cover a bargain (but if you want to go the other way, full solar and use your heat pump as a backup, then that is a great alternative).

[cleancloths]

Thanks, that is sort of what I thought. I got a catalog from InTheSwim and they have a system for inground pools that is about $450 that has 4 panels that are 2' by 10' - that is where I came up with the 80 sqft.

How much heat does you 600sqft system put out - what sort of temperature rise per hour or day do you see. If I did this it would be on the ground or on a slanted platform as my south facing roof is fairly full with a 10kw solar electric system which produces about 1200 kwh of electricy a month.

[mas985]

I tried running without a cover last year and the temperature swing of the water was quite large. With the panels, the best gain I have seen is about 8 degrees a day but I would lose 6 degrees overnight without a cover, 90 degrees during the day and 84 the next morning. So it will work without a cover but you may experience high temperature swings. With a cover and you will be swimming much earlier in the year. I hit 80 degrees near the end of March this year.

A typical panel will produce about 1000 BTU/sq-ft/day in optimal conditions. This will drop depending on time of year, wind, outside temp, etc. So best case, 600 sqft will produce about 600000 BTU/Day. So for 28k gallons, that will be about 2.5 degrees per day. However, you have to factor in the normal solar gain which could be as much as 4 degrees per day. So you should see a about a 6 degree temp rise but there are so many other factors that it is really difficult to predict exactly. Also, as the pool temp rises, the amount of heat you can add will reduce.

[CarlD]

I think you need at least 3 20'x4' panels--about 3 times what you propose. Realize that I think standard recommendations are 'way too high, too.

[tphaggerty]

My profile is very similar to mas985. I can get about 4 to 6 degrees a day (my panels - unfortunately - face east/slightly north, so they are not ideally positioned, that is why I added the extra panel set). But, here in the NE, I easily lose 4 a night without the cover and still lose 2 with it on. And I don't run my pump at night so the water doesn't get stirred up.

Last year, we were over 86 almost all season, into the low 90s sometimes (the boys don't like it that warm, the girl wants it as warm as possible). My biggest problem with heat is RAIN. A good day of rain can drive the temp down 10 or so degrees even with the cover on (screws up my pool chemistry too). But, as soon as the rain stops and the sun pops out, the solar kicks back on!

Overall, I love it. My system cost was pretty high because I paid for it in 2 parts, maybe 6 grand total (and I have a 120' run to the roof - thats about 1,000 just in piping!). But, we don't have gas here, propane is way too expensive and a good heat pump around here will go about 3 to 4 grand plus about 500/year operating. Last year we opened in early May, closed in late October, NOBODY else around us did that, so it has been worth it.

[jmcst25]

I have a 20x40 IG - & installed 6 panels (4 x 20) on my roof (south facing) in west PA last year. I can get 8 degrees a day - best case I got 30 degrees in 3 days last year on opening - but easily kept it 86 or higher all year using solar cover at night.

This was well worth the effort - this year I'm selling the heat pump.

If you are interest in solar panel you must read the page tphaggerty recommended - powermat.com. It is the best source to educate yourself on how they work. His recommendation helped me out alot last year.

There was no local installers in my area - I purchased the panels online (not from powermat) and found a local Gen Contractor to attach to the roof.

[Aranon]

How much you want for the heat pump?

[jmcst25]

Aranon - I left you a PM.