SWIMMING POOL COVERS
Swimming pools lose energy in a variety of ways, but evaporation is by far the largest source of energy loss. Evaporating water requires tremendous amounts of energy. It only takes 1 Btu (British thermal unit) to raise 1 pound of water 1 degree, but each pound of 80ºF water that evaporates takes a whopping 1,048 Btu of heat out of the pool.
Types of Swimming Pool Covers
Technically, all you really need for a pool cover is a large sheet of plastic. Plastic meets the requirement of being a vapor barrier. But a large sheet of plastic that you get from the lumber store is probably not your best choice. It will be very difficult to handle and store, it tears easily, and sunlight will deteriorate it rapidly.
You can use a sheet of plastic, but it will be very inconvenient and it will probably only last 1 to 2 seasons maximum. It’s best to use a cover designed specifically for swimming pools. They’re made of special materials, such as UV-stabilized polyethylene, polypropylene, or vinyl. They can be transparent or opaque. Covers can even be light or dark colored.
One of the lowest cost covers made specifically for swimming pools is the bubble (or solar) cover. Bubble covers are similar to bubble packing material except they use a thicker grade of plastic and have UV inhibitors.
Vinyl covers consist of a heavier material and have a longer life expectancy than bubble covers.Insulated vinyl covers are also available with a thin layer of flexible insulation sandwiched between two layers of vinyl.
Outdoor pools gain heat from the sun, absorbing 75%–85% of the solar energy striking the pool surface. This is an important contribution to the pool’s heating needs. A pool cover will decrease the solar gain contribution to some extent, depending on what type you use.A transparent bubble cover may reduce pool solar energy absorption by 5%–15 %. A completely opaque cover will reduce it by 20%–40%. You need to consider this when selecting a pool cover.
You also need to decide whether you want a manual, semi-automatic, or an automatic pool cover.You can manually pull the cover on and off, fold it, and place it somewhere out of the way. You can also purchase a pool cover reel to help manually roll up the pool cover. The reel, usually on wheels, can be rolled out of the way.
Semi-automatic covers use a motor-driven reel system. They use electrical power to roll and unroll the cover, but usually require someone to pull on the cover when unrolling, or guide the cover onto the reel when rolling up the cover. Semi-automatic covers can be built into the pool deck surrounding the pool, or can use reels on carts.
Automatic covers have permanently mounted reels that automatically cover and uncover the pool at the push of a button. They’re the most expensive option, but they’re also the most convenient.Some pool covers fit into tracks along the sides of the pool. This prevents anything or anybody from getting into the pool. They even support the weight of several people. If liability is a concern, these are a good option to explore. They can be run manually, semi-automatically, or automatically.