Heater: Wood or LP?

[strmh]

About to install an 18 x 36 IG and also want to heat it.

I've got an EKO downdraft gassifier (205K BTU wood boiler) that heats my house and separate shop in the winter and I'm considering piping a loop to the pool for a heat exchanger (during summers in Maine).

After doing some light research I'm finding that some state the pool water pulls so much heat that boilers can't keep up with the demand.....although I suspect that may have to do with balancing valves to manage return temps.

My other option is an LP unit just for the pool. Initial cost will be a bit more than the heat exchanger option, but ultimately, I want what works best.

Does anyone have any input/suggestions/experience on how wood heat compares to LP??

Thanks,

TH

 

[duraleigh]

Have you done a btu calc for how much is needed to raise the pool temp 2-3 degrees per hour? You will find your current btu requirement miniscule compared to what the pool will need.

I didn't understand that and attempted it with an outdoor wood furnace (supposedly 300 btu) and I couldn't come close to the btu required.

If you decide, I have a spectacular stainless water to water exchanger (500,000) that I am getting ready to put on ebay. :lol:

 

[JohnT]

It takes a lot of energy to heat a pool. A gas pool heater is typically around 400,000BTU. Your boiler would need to run pretty pretty hard to maintain pool temperature. If you have easy wood access and don't mind the smoke and stoking, go for it, but you will probably be disappointed in the result.

Where do you live? What kind of sun exposure does your pool have?

I heat my 20X36 pool with 192ft of solar panels that cost me about $1200, and keep my water between 84 and 90 from about now to September most years here in Indiana. We honestly quit using the pool in the fall because the air is cool before the water is too cool to swim. Solar is cheap to operate, reasonable to install and requires no hauling wood.

 

[strmh]

JohnT,

I'm definitely interested in solar....can you, by chance, give a bit more info on a good source for panels?

I'm in northern Maine, but I can likely position panels for nearly all-day sun in spring/summer.

If you're willing to share, I'd like to know more about your setup.

 

[JohnT]

I have 6 4'X8' Aquasol panels on the south-facing roof of our pool house. I went with Aquasol because they were available in 4X8, and that let me use almost every square inch of the roof I had available.

I easily maintain mid-80s all summer. The grandkids came over the other night and the water was 81 and they acted like it was icewater. I told them they were spoiled by the warm water I usually have.

I usually run mine from 10am to about 7pm, and normally I see 4 or 5 degrees increase from inlet to outlet, though I've seen as much as a 9 degree rise during an exceptionally hot, calm day early last season. I actually got the pool up to 96 degrees a couple of times in September when the weather was cruddy and I didn't watch the thermometer.

Installation is simple PVC and lag screws into the roof. Took me a little longer than it should have because I used up so much of the roof that there was no place to work when I got near the end. I use a manual valve to control it, but I'm considering adding automation since this will be my first summer without kids at home during the day to act as human thermostats.

If you do go with solar, you could still do something with your boiler to supplement it or cover for it on cloudy days.

I would seriously consider adding an auto cover to the pool. It is a serious chunk of cash, but it is far and away the easiest way to keep the pool warm and save the heat you put into it. Every time I roll up my solar blanket, I think about it.

 

[strmh]

Excellent information, thank you.

Do you leave the panels on the roof year-round? I'm assuming there's a way to drain for winter months, just curious if they are built to withstand some harsh conditions such as snowfall and ice.

Again, thanks for the advice.

TH

 

[jblizzle]

Most solar setups should be designed to automatically drain when the pump is turned off. I also have a valve at the bottom of my panels that I open in the winter to make sure they are empty, but my winter is very mild.

I think some people use air to blow out the panels as well to ensure most of the water is out for the winter.

There are a lot of good pictures and animations on this site to give you a better idea of the plumbing, etc (although some of them are overly complex):
http://www.h2otsun.com/

 

[JohnT]

Excellent information, thank you.

Do you leave the panels on the roof year-round? I'm assuming there's a way to drain for winter months, just curious if they are built to withstand some harsh conditions such as snowfall and ice.

Again, thanks for the advice.

TH

The perspective hides it, but the panels are tilted so the right side is lower than the left, so the panels drain. I leave them up year round. The roof is about 10/12, and we aren't in heavy snow country. As soon as a square inch of panel is exposed to the sun, the snow melts off.