Roof Mounted Solar Heater

[mminetti]

I have a standard 18x36 IG vinyl lined pool in Central New jersey that we would like to add heating too. I have an east facing roof which does appear to have full sun from 10:00 until 4:00 each day. Without heat I can get our pool up to about 84-86 degrees during July/early August, but it drops into the upper 70's this time of year. What I'm looking to do is get the pool temps a consistent 85+ from early June through mid September.

I have looked at gas heaters which have a relatively low upfront cost but huge operating cost. The heat pumps seem like it would fit the bill but again the ongoing electrical costs is less then ideal. Then I started to explore the roof mounted solar systems where the water is pumped to the roof, trickles through the panels and returns to the pool in what each company explains as a +10 degree or more delta.

Do the solar panels work in New Jersey or are they more suited for warmer climates?
Are there any hidden costs that the vendors forget to mention in the web ads?

I am handy enough to DIY so the systems seem to have a up front cost of about $$2-3k with little to no yearly costs.

 

[JohnT]

Solar panels will work in northern areas. My experience in Indiana is that they don't extend the season a lot, but they do make the water much more comfortable near the ends of the season and during cool spells.

An east facing roof isn't ideal. West is better, and south is best, though a fairly shallow roof pitch might make the east side "not too bad".

My panel outlets are typically 4-6 degrees warmer than the pool, and I have no trouble holding 87 degrees most of the season. My pool is about the same size as yours, and I have 6 4'x8' panels on a south facing roof.

With or without panels or a heater, the first step to a warmer pool will always be a solar blanket. You lose so much at night without one, that it can be difficult to get the water warm during the day even with a heater. We are have lows in the 50s and highs near 90 right now, and I probably would struggle to keep the water swimmable without a blanket.

 

[tphaggerty]

Panels absolutely work in the Northeast. One of the best flyers I have ever seen on Solar Pool heating comes from the Canadian government!

I'm north of NYC in the Poughkeepsie area. My roof mounted solar faces slightly north of east. I do get sun more than from 10 to 4, more like 8 to 5 but in the summer I can get my pool above 90.

I have a LOT of panels for my 20 x 40 inground, but mostly for quick recovery. We open in early May and have closed as late as early November (though that is pushing it).

There is a great solar installer in NJ, don't remember the name but do a web search.

Good luck and go solar!!

 

[jblizzle]

Not sure of the market up there, but there are often people selling used solar panels on craigslist down here. If you are going the DIY route, certainly something to consider.

From what I have seen, people have gotten the panels for $1-2 per sqft.

 

[Den]

Anybody heard of http://www.h2otsun.com/ company? Are their panels any good?
I am debating between solar panels and heating the water by domestic tankless water heater via heat exchanger.

Another question - this company says that I need 75% of the pool sq.ft. to heat. For my 16x32 pool this is 384sf or 12 panels (4'x8'). Is not it overkill? JohnT has only 6 panels...
Their system pumps pool water through the panels. Does it make sense to install like 6 panels and add more later only if needed?
I am in Kelowna, BC, Canada (just north of WA state. A lot of sunny days here. but cool nights).

Thank you all!

 

[Den]

P.S. I have south faced roof, no shadow. The pool has 9' deep end, so about 20,000 gal. Does it make sense to have automatic control system?

 

[yeggim]

P.S. I have south faced roof, no shadow. The pool has 9' deep end, so about 20,000 gal. Does it make sense to have automatic control system?

An automated system really shines on those "iffy" days. On those days where there's low clouds and/or the air temp is lower then the water, an automated system will only run water through the system when there's a net heat gain. A manual system left open could cool the water at times in those and some other conditions. Those are the kind of days that usually bracket the beginning and end of the swimming season.

 

[cramar]

General rule is square footage of panels should be at least 50% of the square footage of pool surface (ie: pool surface = 300 square feet so you need at least 150 square feet). I have 160 square feet on my roof for a 20' pool, another panel would be great but I'm happy with the performance.
I live in northern Ontario Canada and they certainly work here, although I don't expect that they will extend the season all that much, at some point the night time heat loss simply overtakes the day time heat gain.
An east facing roof will certainly make a difference and you'll get reduced heat, mine faces west and I have come to realize that a south facing roof is the best. That said, it still provides heat.

Last year we struggled to get into the 80's, this year we were well on the way to 90 a few times but I turned them off - too warm. It's great that people enjoy the pool more with the warmer temp.

 

[tphaggerty]

If you can afford them, the more panels, the better (up to the point that your pump can provide enough flow).

There are 2 considerations with any heater, (1) how warm can I get my pool and (2) how quickly can I heat it up. In both cases, more panels work better. But it is heat recovery that really makes a difference. An extra panel or 2 (or 3 or more) can make the difference between having warm water today or tomorrow and having warm water 3 days from now.

Plus, it is quite a bit more expensive to add panels than to just get them in the first place, especially if you have someone doing the work for you.