How to heat pool?

[GWB]

Helps ya float, too.

[gfretwell]

I have a solar heated pool and a thermometer, (as do several neighbors) you have a sliderule

[BobK207]

I fail to see why you find it necessary to insult someone who questions or doubts your analysis.

btw if add some white space to your posts........

those of us who might have the ability & desire to check your calcs could do so w/ less frustration

also you might consider the use of units.

cheers Bob

[nicksanspam]

And a vast supply of ignorance? :-)

This is 300-year-old physics.

Nick

[nicksanspam]

OK.

With RC = R1x4.5'x62.33lb/ft^3x1Btu/lb-F = 280.485 hours, the pool temp would drop from 80 F at 9 AM to 48.8F+(80F-48.8F)e^(-6h/280.485h) = 79.33967251 F by 3 PM on an average January day in Austin :-)

US R1 (the pool cover thermal resistance) is 1 ft^2-F-h/Btu, and 1 cubic foot of water weighs 62.33 pounds, and 1 Btu can warm 1 lb of water 1 F. Everything but "hours" nicely disappears in the rest of the RC calc...

Happy now?

Nick

[gfretwell]

Ther problem is not with the physics, it is with the real world performance of the cover and other places where the heat escapes. I agree the heat all started in the water but keeping it there is not as simple as your numbers would indicate. A degree or 2 makes all the difference when you actually get in the water. I can swim in 27c water, 28 is better but 26c is too cold. I suppose folks in the frozen north are more tolerant of cold water.

[nicksanspam]

Well sure. We need to cover the whole pool surface with no exposed water, and no gaps for airflow nor leaks in the cover.

I disagree. It's pretty simple :-)

Nick

[BobK207]

Dear Nick-

Thanks for the effort but you don't have to go out of your way to try to make me happy. :)

I wasn't unhappy but typically your post filled with runon calcs that are very hard to follow...even for an ME with 30+ years of experience.

I doubt if any other ng readers even attempt to make sense of them

The units did help but I like lots of white space......improves the readability.

If you want people to take your calcs seriously you need to make an effort to make them understandable. ......

otherwise it's just "another a stream of numbers.from that obnoxious, know-it-all guy from villanova"

You also might consider using an unafilliated email address...IMO a lot of your posts reflect poorly on your organization.

cheers Bob

[gfretwell]

That's a man without a wife or kids. The cover never gets put on perfectly and a cloudy day really screws up the heating. A little rain really puts you in the crapper. As they say on the sticker on a Hummer "Your mileage may vary but it will certainly be less than this"

[nicksanspam]

How sloppy can you be? Wrinkles are OK. Leaving less than 10% of the pool uncovered is probably OK in Texas...

No. That's OK, the pool cools slowly, with a 280 hour time constant.

That could be a bummer, with a large puddle on top of the cover. Maybe the cover should have a few leaks, eg a 1/4" hole every 2'.

Nick

[JT]

Nick,

Aust>

[nicksanspam]

Au contraire, NREL says the annual average air temp, ie the deep ground temp is 68.6 F, and that may be unimportant for this pool.