The convex (Curved out) nature of the bubbles act as tiny magnifying glasses that take the sunlight from the top and focus it generating heat that is transferred to your pool water. (Ever burn paper with a magnifying glass on a hot sunny day?) Additionally the airs space created is also an induction barrier preventing and exchange of heat and cold from water to air and visa-verse.
Do I put the bubble side down to hold the heat in?
you make sure the bubble side is facing down on the water.smooth facing uo toward the sky.
All Solar Pool Covers are placed on your swimming pool with the bubble side down, or facing the water. This allows an air pocket to form under the cover to trap heat & provide the maximum insulation value the cover is designed for. -Charlie Goss President DPD Pools / PoolDeals.com
The didstributor says bubble side down ( for instance solarcovers.com). I do mine bubble side up because when I reel it in the bottom part is in contact with the pool edge and the friction may damage the bubbles.
Personally, I disagree with the logic used by those above. If the bubbles are up, there will be larger surface area to absorb the sun's heat. Increased levels of heat absorption seems more important than the rate of heat transfer, especially when considering the fact that heat transfer takes place almost instantaniously.****i have tried it both ways, bubbles up or down. makes little or no difference heating. with bubbles down, though, it is easier to clean debrie off the cover and keep it clean.
The smooth side of a solar pool cover should face down toward the water to help trap heat and prevent debris from entering the pool. The bubbles or air pockets on the cover should face up, as they help to capture and retain heat from the sun.
the bubble side go facing up obsorb the sun
Spread the cover out over the pool, (bubble side down). Let the cover "relax" for a day before cutting. Then, with regular scissors, slide-cut the scissors along the perimeter of the pool to cut. Try not to "chop". You will be surprised at how easy these covers are to cut. I have heard that one end of the cover should be cut a little short, perhaps 6 inches. However, I have never heard the exact reason for this so I can't verify that it's correct. I did it with mine on one side, the side opposite the reel, and it doesn't seem to affect the temperature adversely.
Solar pool covers work by trapping the sun's heat and preventing it from escaping, which helps to warm the pool water. The cover also helps to reduce evaporation and heat loss, keeping the water temperature higher for longer periods of time. Additionally, solar pool covers can help to prevent debris from entering the pool and reduce the need for chemical treatments.
Some suction side pool cleaners will "hover" because sometimes air gets entrapped in the shell especially if it was taken out of the water for some reason and then returned to the pool. Bring the cleaner to near the surface of the water and near the edge of the pool deck. Reach down and gently tilt and sway the cleaner head from side to side. You may have to practically turn it upside down in order to remove the air bubble. Once that is done release the unit to see if the condition continues. k
Down, if you hope to heat your pool with it the bubbles (in theory) will heat up from the flat side. As there is more surface area from the bubbled side more heat (energy) will transfer to the water. I've never read any studies myself but I've read differing opinions from people in other posts. Some state the the solar cover actually blocks the sun and less heat is transfered on sunny days and that it is more beneficial to use take the cover off. Personally I find that if you leave the cover on when not using the pool, except when it's raining, the temperature stays the highest. Ensuring the cover is clean and there is no standing water on top of the cover really helps.
Usually there is a ladder on the side, or steps leading down into the pool. Enter that way and you'll be safe. :)