Solar Pool heater suggestions

[Hilda88]

Hello all,
We are moving to our new home next week, so serious discussions regarding our new home are going on now. We have left space in our backyard to construct a swimming pool. We got an outline design of swimming pool. This is the rough design of our swimming pool http://www.soldapools.com/blog/desig...imming-pool-2/. We will be making small changes and upgrade the design later. My husband has an idea of implementing solar heating in our pool. But we don't have much knowledge on how to start this process. Hope that many of you here would have already used solar heating in your pools. It would be really helpful if you share some information about solar heaters, their working and their installation process.

[J.P.M.]

Go to : energy.gov and search for "pool heaters". Lots of basic info.

Before a pool heater, a pool cover is usually a more cost effective first step. Manually (human) powered covers are, by far, much more cost effective than solar pool heaters. For your situation - a not yet built design - depending on size/shape of the pool, an integral (and probably motorized) pool cover becomes a possibility. Although more costly than a cover that's manually placed/removed, it's a lot less hassle. The aesthetics are also often less of a concern.

When I lived in Albuquerque, I had a motorized cover that was very dark brown color. It therefore also doubled as a pool heater. The pool was covered when not occupied. The water temp. stayed greater than about 80 F. from approx. early April to the end of Oct. or so. the CH4 fueled heater that was in place was not used at all once the cover color was changed to dark brown. Added bonuses of a motorized cover, besides being much easier to set/remove and keep in place were that the water was a LOT easier to keep VERY clean and the cost of maint. and chemicals dropped by something like about 2/3 or more.

Like a lot of folks who own a property with a pool they must maintain, I'll never own another property with a pool. But, if I did, the first thing I'd do, if one was not already in place, would be to reduce the heat loss with a cover, and make that cover a motorized affair that was black (the dark brown was a negotiated compromise to SWMBO's aesthetic sensibilities). While more expensive than a manual cover, on the cost/benefit scale, if I can afford a pool, I'm ipso facto rich enough to trade some $$s for the avoided labor/PITA of a manual cover. If I still needed more heat, that's when I'd consider a solar pool hater heater, which heater, BTW, will then be smaller (read less $$ and probably less aesthetically offensive) when used in conjunction with an effective cover.

[Hilda88]

Thank for J.P.M for the useful piece of information. Seems like pool cover is an great idea.. Will surely use them in our pool. So, will I need a solar heater if I use a pool cover??

[inetdog]

Thank for J.P.M for the useful piece of information. Seems like pool cover is an great idea.. Will surely use them in our pool. So, will I need a solar heater if I use a pool cover??

It depends on how hot you want the pool and for how much of the year.

[foo1bar]

It depends on how hot you want the pool and for how much of the year.

And your location.

[J.P.M.]

Thank for J.P.M for the useful piece of information. Seems like pool cover is an great idea.. Will surely use them in our pool. So, will I need a solar heater if I use a pool cover??

You are welcome. As others note, it depends.

Water that's warmer than its surroundings loses heat.

The usual goal is to have water at a temp. that's warm enough to be comfortable, and not go broke doing it, or with an excessive amount of hassle, either as a lot of labor or an insult to aesthetics.

In warm climates, losses may be low enough that any heat addition is unnecessary.

In cold climates, and/or for extended use, more attention to reducing heat loss (a cover), or more heat input to make up for losses, or both, will be required. Not needing as much additional heat input via a cover is always a less expensive option that a solar or a fossil fueled heater, and therefore the first step. After that, and depending on what you want out of it, a solar pool heater may be the next step.

Just opinion here: CH4 ("natural gas") seems to be reasonably cheap lately and looks to remain so (???) for some time. As big of a fan of solar as I am, and depending on how big/costly/visible/etc, a solar pool heater might be for your situation, I'd consider/investigate a gas fired heater as an alternative to a solar pool heater - but only after an effective pool cover.

[tstahoe]

Newbie here. For warmer climates, what about a simple black insulated back with clear tubing for a solar coil? Wouldn't this allow for more of the sun's energy to get into the water faster? My thinking is from camping showers with one black side and one clear side. Also, I've heard clear or lighter colored blankets for pools are better than the darker ones if heating the pool is desired.

[foo1bar]

Newbie here. For warmer climates, what about a simple black insulated back with clear tubing for a solar coil? Wouldn't this allow for more of the sun's energy to get into the water faster?

It depends on:
How well the black background will re-radiate it's heat into the tubing.
How much heat is absorbed directly by the water inside the clear tubing vs. black.
What the transmission rate is for heat from outside of the tubing to the water inside.
What difference in flow characteristics are (diameter of the tubing, friction of the water against the walls of the tubing)
How weather conditions will affect things for one vs. the other) (ex. wind; different levels of sun)

My assumption is that simple black tubing like a fafco panel is the most cost effective for most climates.
And that if it were more cost effective to go with what you're describing, you'd see somebody selling it and showing off studies to prove their solution is better.

[PNPmacnab]

Saw a program where they added on to the pool pump a heat transfer coil to the heat pump. In the summer it acted as a heat sink to the AC and in the winter a heat source for the heat pump. Talk to some HVAC guys.

[J.P.M.]

It depends on:
How well the black background will re-radiate it's heat into the tubing.
How much heat is absorbed directly by the water inside the clear tubing vs. black.
What the transmission rate is for heat from outside of the tubing to the water inside.
What difference in flow characteristics are (diameter of the tubing, friction of the water against the walls of the tubing)
How weather conditions will affect things for one vs. the other) (ex. wind; different levels of sun)

My assumption is that simple black tubing like a fafco panel is the most cost effective for most climates.
And that if it were more cost effective to go with what you're describing, you'd see somebody selling it and showing off studies to prove their solution is better.

If the goal is to heat swimming pool water in the most cost effective way: Use a black piece of plastic over the pool and keep the upper side free of moisture. Cost is low, close to max. amount of solar energy will get to the water, evaporative losses, which usually make up something like half the losses will be low to almost zero. Convective losses will be about the same as an uncovered pool.

However, as a practical matter, keeping the cover in place as well as removal and placement is a real PITA, and mostly unworkable from a practical and aesthetic standpoint. Material service life will be low, probably less than a few months. But it is most likely the cheapest way considering material cost only.

For separate flat plate pool heaters, I'd agree that the best practical of the solar solutions to heating pool H2O is probably the Fafco type heaters. They do cost a bit more, but they are quite efficient and fit for purpose, which is more than can be said for most of the DIY stuff if those characteristics are of any importance. Not knocking DIY'ers, but beyond a hobby and/or a learning expericence, most of it is not an effective use of resources.

If I understand what Tstahoe is writing, (s)he is referring to the solar shower bags that have a clear cover over a black bag. They do work. The clear plastic is there to lower the convective heat loss some and help achieve higher temperatures for comfort.

In most any reasonable climate, pool heaters work best with no covers, and the highest mass flow rates and velocities consistent with reasonable pumping costs and other component requirements.

The idea of clear tubing being better than dark and opaque, and what I'm assuming is some notion that heat is conducted through plastic at the same rate as through metal to a tube of some sort, is not correct, nor is the idea that some black background will reradiate some energy onto some tubing.

Non metallic material is OK for pool heaters but the thermal conduction path lengths need to be kept much shorter and/or with greater section thicknesses than for metals as f(thermal conduction of the material).

[wayner92]

Saw a program where they added on to the pool pump a heat transfer coil to the heat pump. In the summer it acted as a heat sink to the AC and in the winter a heat source for the heat pump. Talk to some HVAC guys.

This makes a ton of sense as many people, or at least me, are using electricity to cool the house and natural gas to heat the pool. Why not transfer the house's excess heat to your pool water?

You probably mean This Old House: https://www.thisoldhouse.com/how-to/...ir-conditioner

I wonder why these aren't more common?

[wayner92]

Like a lot of folks who own a property with a pool they must maintain, I'll never own another property with a pool.

I am the opposite - I grew up in a house with an in-ground pool and as soon as I could afford it I bought a house with a property large enough for a pool and put one in. I don't think I will ever own another property without a pool. And that is despite living in Canada where you need to heat the pool and can only use it from June-Sep.

[paris401]

i just got an estimate (we r in ny) for a heliocor system- black tubing goes on the roof for a 18x36 inground... price installed ...9,200 bucks- WOW... thats a lot of $$$- but I figure the payback in not using my propane heater is about 4years... not a bad payback period, but a lot of upfront $$$$.... there is also another 'unique' solar heater that they place up in your attic to take advantage of the heat up there- its black tubes that suck in attic heat... and lowers the attic heat .. not sure of the pricing... trying to gather info from an installer.... downside ofcourse is u better not have a leak...

[J.P.M.]

i just got an estimate (we r in ny) for a heliocor system- black tubing goes on the roof for a 18x36 inground... price installed ...9,200 bucks- WOW... thats a lot of $$$- but I figure the payback in not using my propane heater is about 4years... not a bad payback period, but a lot of upfront $$$$.... there is also another 'unique' solar heater that they place up in your attic to take advantage of the heat up there- its black tubes that suck in attic heat... and lowers the attic heat .. not sure of the pricing... trying to gather info from an installer.... downside ofcourse is u better not have a leak...

Forget the attic heat exchanger - that's B.S.

[inetdog]

Forget the attic heat exchanger - that's B.S.

And on the same topic, the best way to reduce the attic temperature (other than improving ventilation) is to intercept the solar energy above the roof and keep it out of the attic. That is, among other ways, with solar PV or solar thermal panels. Especially if you provide adequate air space between the PV panels and the roof.