A pool cover is an essential item for any pool. They perform a multitude of tasks for a very small outlay of cash. A pool cover which fits well to the shape of your pool will:
Did you know your pool could lose between a tenth of an inch and three quarters of an inch of water per day? What does that translate to? Let's go to our 20' x 40' pool again. Only surface area is needed (depth is unimportant) and surface area here is 800 sq feet so we finish up with about 6.7 cubic feet of water evaporating if you lose a tenth of an inch and about 46.7 cubic feet at the three quarter inch level. That gives 50 to 350 gallons or 416 to 2,915 pounds of water per day.
Remember (from What Size Pool Heater Do You Need?) how it takes 1 BTU to heat 1 pound of water up by 1⁰F? Well 1 pound of water evaporating takes 1,048 BTU with it! That means you lose 436,000 to 3,054,920 BTU per day - a 400,000 BTU gas heater would have to run up to 8 hours just to replace the heat lost through evaporation.
A well-fitted pool cover can cut evaporation by up to 95% keeping all those lovely BTUs where you want them. There are factors like humidity, wind speed, air temperature and water temperature which change the evaporation rate a great deal but the figures above can be worked out for any pool given the surface area.
Not all pool covers are the same. Some covers are designed to help heat the pool while others will actually stop some of the sun's energy getting into the water. Some covers sit directly on the surface of the water and are free-floating while others are attached to mounts around the outside of the pool and act as safety covers. These can prevent accidental drownings and stop small children entering the pool. Free-floating covers can increase the risk as they can wrap around a person falling into the pool.
Solar Pool Covers - What A Pool Cover Can Do For You
~ Who else wants to extend their swim season? ~
reduce evaporation by up to 95%
save up 75% of heating costs
save up to 60% on pool chemical costs
stop debris landing in the pool.
Pool covers are usually made from a type of UV stabilized plastic such as vinyl, polyethylene or polypropylene. They allow most of the solar radiation through and then trap it in the water. Most will use an insulating layer of bubbles (similar to bubble wrap) or a reflective layer sandwiched into the material. Depending on the quality of the material, pool covers can last from a year to ten years - the better quality ones often have a five to eight year warranty.
Solar pool blankets can be placed on and removed from a pool by hand or by using a reel. A reel makes life a bit easier - by simply winding a handle you can remove the cover easily without damaging the cover. Sometimes, for large or irregular shaped pools, it is easier to use two covers.
Pool covers cost very little when you consider their potential savings. The volume of water they can save is amazing and when you add the cost of chemicals and heating purchasing a solar cover becomes a must. For example, a cover for a 20' x 40' rectangular pool should cost between $50 and $200 including freight to your door!
Pool blankets, blanket reels and other solar equipment are available on the following supplier links: