Comparing Pool Heating Options

[famousdavis]

I know you've set aside a heat pump as an option as a "paid energy pool heater", but I'm curious to know, why?

We turned on our heat pump for maybe two hours last evening to warm our spa to 95 degree. The heat pump was only on for a portion of that time, though, as it didn't need to run the full two hours to get the spa up to 95 and keep it there.

We enjoyed the warm spa, then turned off the heat pump. I didn't need to worry about having a warm attic or having the sun outside (we warmed our spa after dusk). The heat pump appears to use about as much energy as my home central A/C does. By running my heat pump just for two hours, it will hardly put a blip on my monthly electric bill.

Wouldn't a very low-cost, somewhat higher maintenance option be to use a solar blanket? Once the blanket is purchased, you've got the trouble of covering/uncovering your pool, but maybe it's best for a "free" pool heating option, as you don't have to run either your pool pump or air conditioner.

[solar]

Hey you make a good point. But really I am just a treehugger at heart, its the reason I am in the solar biz. In my last post (which never showed up?) I mentioned that I have a roof full of solar already. It's a personal choice, I guess I can't bring myself to consume fossil fuel for such a luxury.

I already feel bad about running my AC but of course I have convinced myself that it is a necessity ;-) Running a heat pump pool heater to put 500,000 BTUs per day in a pool, at a COP of 5, eats up 29 kWh per day. That's not a lot of money, but it equals burning 1/2 ton of coal every month.

[PoolDoc]

Solar, I'm going to mod this in, and elevate your membership so you can post generally, but . . .

I'm not a treehugger, and I don't do "PC": I'm a rationalist, and I expect that of you. (I was a tree-hugger once - have you ever seen one of the old green "eco-flags"? Think 1970's)

I have nothing against solar heat, and as you may have noticed, many folks here use lo-tech black poly panel solar heat. But, I have no romantic attraction to it, either. And frankly, all the "love mother earth" bumper stickers I see on the 14 mpg SUVs, complete with added high-air-resistance kayak and bike racks, that are common in the 'hippie' part of Chattanooga irritate me no end.

So . . . I'm moving your post to the China Shop. The rules there are pretty simple: prove your point, or take your lumps!

But, before you promote solar generally, you need to make . . . and defend . . . your case there. If you can successfully defend the idea that expensive solar units -- with life cycle $$$ *AND* manufacturing KWH accounted for -- make sense, have it it, and welcome! For myself, I'm skeptical, but uneducated.

But, if you can't make the case, hush up!

[solar]

Ben you make good points and ask a tough question about kWh used in manufacturing solar equipment. That is a problem and it has a "ROI" of several years before the energy and emissions used to make a solar panel are offset by the "savings". But let me say that I did not join this forum to promote solar. Really I think at this point solar speaks for itself and has its followers, detractors, wait-and see'rs and those who don't care. I am not here to convince anyone or even discuss it further. My interest is in examining alternatives to solar, mostly for my own use, while using the most green approach that makes sense. For example the hotspot company product or the solarattic product I mentioned in my original post. Thanks to CarlD for his insight, and after researching the cost of solarattic, I have ruled out the attic idea for several reasons. I have also talked to the hotspot people and they seem to have a good product for someone in my situation. Since I bought this house that has a pool, I have learned about the real need for pool heating and understand why people buy it. I don't understand how the previous owners did without it actually. I am sure I will be back here with more questions and at some point may be able to contribute some answers for others. And if I get a hotspot pool heater I will post back with my review.

[Watermom]

Solar ---- Just a reminder that new members have to have their posts go through a moderation queue before they appear on the forum. So, that is why your post didn't appear immediately. People who become subscribers remove this moderation requirement and thus do have immediate posting.

(BTW -- I deleted your other post saying that you couldn't post.)

[PoolDoc]

But let me say that I did not join this forum to promote solar.

Good!

We welcome all kinds of information . . . but not promotion!

[chem geek]

Heating using solar panels is not free because generally speaking it takes higher pump speeds and/or higher head (pressure) to use solar heating and that uses more electricity. Nevertheless, they are usually a heck of a lot less expensive than gas heating. Heat pumps in some situations might be close if one accounts for the pump electricity cost difference. I know that in my own pool, solar heating is far, far less expensive than gas heating and that's even with extraordinarily high marginal electricity rates of 40 cents per kilowatt-hour vs. still high but not extraordinary marginal gas rates of $1.40 per Therm. When I am not running solar, I can run my Pentair IntelliFlo variable speed/flow pump at 26 GPM using 275 Watts, but when I am running solar through 12 panels with very long runs on a 1-story roof at 48 GPM it uses 1500 Watts.

It would be very interesting to do a full analysis of solar vs. heat pump taking into account the pump electricity costs assuming a variable speed/flow pump (or possibly a 2-speed pump). I haven't seen anyone do that thoroughly.