Of pool water during the hottest part of the year in your area.
The area I am most interested in is the Houston area.
Thanks.
The area I am most interested in is the Houston area.
Thanks.
Mark, is this your own data... or do you consider this universal?mas985 said:Pool temps generally will follow the average daily temperature within a few degrees so just look up your area's historical temperatures on wunderground.com. A solar cover will increase that average by 3-5 degrees.
The cover was removed because the water was uncomfortably warm and there was a gradual cooling off toward the end of the month, so your explanation makes sense. This was not a controlled experiment, of course --- I just scanned my logs for water temperature and cover usage on a weekly basis, so don't have sufficient data that would support any particular hypothesis. If we modify Mark's statement a bit to stipulate no cover usage or solar panels, zero precipitation, a narrow range of relative humidity, wind and barometric pressure (evaporation rates) perhaps it can be universalized. A one-minute thought experiment would indicate that the water must be fairly close to a (moving) average mean. Or, in language I loosely attribute to duraleigh's perspective on treatment dosing: "close enough!"chem geek said:So you'd expect perhaps 80F or so without a cover and 90-95F when using a cover, but it sounds like you getting 86-94 without a cover and 95+ with a cover. Maybe your use of the cover up to June did heat the water to 90-95F and removing the cover only slowly has the water temperature drop. Does it continue to drop (albeit slowly) throughout the month when you have the solar cover off?
I guess the variables you allude to must be shifting my Sacramento July pool temp higher than what would be expected by the analysis. The biggest surprise for me is the estimated evaporation ("average water loss") during a week with the solar pool cover in place... only 14% water conservation achieved with a pool cover?mas985 said:But again, there are a lot of variables that go into the pool temperature so the results can vary by quite a bit.
High: Low: Average:
Temperature: 105.1 °F 56.5 °F 77.2 °F
Dew Point: 64.4 °F 44.4 °F 53.8 °F
Humidity: 78.0% 17.0% 47.4%
Wind Speed: 11.9mph from the SSE - 1.7mph
Wind Gust: 17.9mph from the South - -
Wind: - - South
Pressure: 30.03in 29.69in -
Thanks for the reply... I wouldn't say mine fits like saran wrap, but there's very little perimeter gap (it abuts the water tile pretty snugly and creases in areas at the center). Assumption is that the cover is on 24/7 and has no gaps wider than 1/4 inch along the perimeter. I can think of only two vulnerable areas --- the skimmer and the auto fill, but can't believe that these areas would allow hundreds of gallons of water to evaporate in a week.bk406 said:Well, my solar cover doesnt exactly fit tight like saran wrap. The edges of the cover on one side dont go all the way to the edge of the pool.
Even with my cover on, on a crisp fall morning, the water vapor looks like dry ice fog coming off. I still get pretty good heat retention though.
I would guess that most people who have solar covers have gaps around the perimeter of the pool. I think you are assuming a solar cover is more like a seal when its really not. Also, water evaporates 24/7, so it's evaporating when the cover is off during the day too.