Rose | 
01 18th, 2011| 
This may sound like a dumb question, but I am trying to find cost-effective ways to heat my 18′ by 4 foot pool. If I bought 2 solar covers, would that help insulate the pool water. I have 1 solar cover now, but it only warms up about approx. 10 inches from the top down.
Thanks
I don’t think an additional solar cover would help as the way in which they work is based on sunlight penetrating THROUGH the cover, into the water, and an additional layer would reduce penetration.
Back in the late 70s or early 80s my brother had a pool in the Dallas area and we were interested in solar heating and experimented with several methods [all using scrounged materials and buying as little as possible].
He was dissatisfied with performance of the solar cover and we experimented with several methods of heating the pool water which could be done with stuff people threw away on the curb.
The technique that worked best [outstandingly actually] ended up being the use of a couple of dozen old, discarded WATER HOSES. The darker the color the better. In the spring and fall, the final system was calculated to have raised the water temperature by about 15 to 20 degrees F on sunny days.
We coiled the water hoses on the deck in a single layer, connecting more hoses as we got them. We then got a very small [and cheap] electric water pump to SLOWLY [increasing the "contact time"] circulate the pool water through the hoses and back to the pool. We put a cheap electric timer in the circuit programmed to operate the pump during the 10am to 5pm time period, and would over-ride and shut the system down on cloudy days [this prevented the warm pool water from losing heat by heating the atmosphere].
He also used the pool cover, but only as a base for a layer of two inch Styrofoam sheets [scrounged little-by-little out of the dumpsters of Television dealers]. We found that we had to put a tarp [weighted down at the edges] OVER the Styrofoam to keep the wind from removing the insulation.
This system worked so well that it could NOT be used in the summertime as the water would heat up like a overheated spa/hot tub.
During the winter it prevented any freezing of the pool or the recirculating system, and during the spring and fall added about 2 months to the swimming season.
The only negative was that we didn’t "dome" the cover tarp, and a whole lot of rain would collect that required the use of the little pump to remove the water before the tarp, insulation, and solar cover could be removed. Also, a lot of leaves would collect and had to be blown off almost daily during the fall tree shed of leaves.
We thought about it, but never tried making the cover dome shaped to deflect rain and leaves. We still think that would remove, or at least greatly reduce that negative aspect.
By the way, any hose with good connectors on the ends will work. Any holes could be easily "patched" with electrician’s tape as there is virtually little water pressure in the hose and pumping system while operating.
We even used good hoses that had one or both couplings cut off by inserting a short piece of pipe into the hose ends as a coupling. At first we used hose clamps, but found out that the hoses fit tightly enough on the pipes to not need clamps.
Once we had the system tested and tweaked enough, we then moved the coils of hose onto the back side of his south facing house ROOF. The advantages of this are that the hose coils were more closely oriented perpendicular to the Sun and thus operated more efficiently [collected more heat], AND were out of the way off of the pool deck. Not only that, but the heat of the shingle roof contributed to the heating of the hoses and water.
As it proved out over a few years of use [until he sold the house and moved] that pool heating system was an outstanding success. And again, with very little cost!!!!!
City of Sunray Texas is heating their 113000 gallon swimming pool with an alternative solar technology. I
http://www.EnergyBrainiac.com – How to Make Solar Panels – Build Homemade Solar Panels & Save $1000s
