Heating a pool with an air conditioner

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>Does the evaporator still run cold? And if not, does any water

Oops, didn't read that. You ran the thing with the windows closed.
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Yeah. The whole unit is inside the room. Both the evaporator and condensor are operating on the local air. So long as you isolate the two enough (with a plywood baffle to direct the hot exhaust away from the unit) so that they don't instantly swap air, it works a treat.
No... the evap doesn't freeze. If anything, it sometimes doesn't get cool enough -- as the humidity drops, the temp on the evap has to get lower and lower to condense, and the unit is heating the air at the same time it's cooling it <G>.
LLoyd
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"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote in message

Lower the evaporator temp to the dewpoint by partially restricting mass airflow volume across the coil.
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yep. But it's a two-edged blade. Restrict it, and you get less dehumidification when you can use it most, and potentially can freeze the evaporator, if there's too little flow.
All-in-all, it works fine with no restrictions. There's just a limitation on how low a humidity you can accomplish.
And, of course, the usual AC doesn't have a humidistat, so it's just a matter of letting it run continuously, unless you want to do a bit more engineering.
Lloyd
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"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote in message

Tried that.... for some reasons the units would ice up. An A/C guy told me that would be a common problem, forgot what the reason was. But, if they don't ice up, a useful application of an otherwise old beatup A/C unit. Also, if you turn them around in the window during the winter, you have a heat pump.... :)
--
EA


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> Lloyd
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"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote:

The typical water-cooled condenser has the refrigerant tube threaded inside the coiled water pipe, so it is surrounded by flowing water.

The only problem is the typical window AC has the condensate rigged to flow back to the condenser fan and get slung around, to extract an evaporative cooling effect from the water. It probably wouldn't be real hard to defeat that, however. But, it would take a little hacking.
Jon
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It's not hard, and takes no hacking. Just tilt the unit a couple of degrees forward - instead of back - and provide a drain.
Lloyd
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During the summer months, I use a geothermal heat pump to cool the house while simultaniously eating a 45,000 gallon pool; in the fall, I use it to heat the house with up until the point where the pool is colder than our well water at which point I start heating with well water, using surface disposal instead.
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PrecisionmachinisT wrote:

COOL! (pun intended) I'd like to hear more details about this system.
Jon
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Existential Angst wrote:

Adding a water-cooled condenser to an A/C system shouldn't be that big a deal. The problem is corrosion. I'd expect pool water running through condenser to shorten its life considerably. But, on the other hand, it might save enough energy to pay for a replacement condenser coil every few years. it would make a mess of the pool when it blew oil into the pool water, though.
Jon
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No good deed goes unpunished. :(
--
EA


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Replace it with a coaxial coil, ( tube in tube, counterflow ) or add one at the point just prior to where refrigerant enters the condensor coil and adjust charge volume accordingly.
http://tinyurl.com/bhbu5tm
Or you can kludge your own out of a piece of copper line set by placing it inside of a coil of black poly pipe.
BTW: You have mail.
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No it won't. Because the refrigerant temp coming back to the air handler is going to be about the same in either case. The existing condenser is HUGE because it's air based. But it's sized so that the returning refrigerant is near ambient when it goes back. The pool water is going to be typically 80 - 85. At least it would be if this thing does what it's claimed to do. The refrigerant can't go lower than the pool temp, even if this small water based heat exchanger is 100% efficient. So, in my world, the bulk of the energy savings is from the AC condenser fan not running and instead the pool pump being used. The pool pump electricity isn't counted, because the pump would have to run 6 or 8 hours a day to filter anyway.

It ain't gonna do much for SEER, for the reasons noted above.
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wrote:

No it won't. Because the refrigerant temp coming back to the air handler is going to be about the same in either case. The existing condenser is HUGE because it's air based. But it's sized so that the returning refrigerant is near ambient when it goes back. The pool water is going to be typically 80 - 85. At least it would be if this thing does what it's claimed to do. The refrigerant can't go lower than the pool temp, even if this small water based heat exchanger is 100% efficient. So, in my world, the bulk of the energy savings is from the AC condenser fan not running and instead the pool pump being used. The pool pump electricity isn't counted, because the pump would have to run 6 or 8 hours a day to filter anyway.

It ain't gonna do much for SEER, for the reasons noted above. ======================================================== I think you missed the basic point.
Heat transfer to air is *intrinsically* less efficient (by orders of magnitude) than it is to water. Add to that that the water is proly sig'ly cooler than the air to begin with, water cooling of the outside coils of an A/C is a no-brainer.
So no matter how the condenser is "sized" for air, a water bath would radically improve (lower) the returning refrigerant temps. And the hotter the day, the more improvement will be seen.
But, HOW this is actually executed is another story, as Vic implied. He was just making the thermodynamic point that, all other things being equal, the A/C efficiency, due to the heat transfer to water instead of air, would skyrocket. That the A/C exhaust fan is not needed is an added plus, as well.
OTHER things might negate the idea of water cooling, but that's another story.
Why do you think IC engines are water-cooled? Despite the fact that air-cooling technology exists? They've even gone to water-cooling motorcycle engines. Yeah, the analogy is not perfect, but it drives the point home.
--
EA



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Which, as I said, means that you need a bigger condenser coil/fan for air. Which the AC unit already has. It's the big thing with coils on 4 sides, fan on top.
You can transfer the same amount of heat with either water or air, given that they are sized correctly.

Significantly cooler? The whole purpose of this thing is to keep the pool warm. So, if it works, then the pool is gonna be 80 -85, which is not significantly different than the air temps. Sure, during some periods, the pool water could be 65, but that's going to be at the beginning of the season. And during those periods, how much do you think the AC is running? In my world, it's not enough so that whatever is going on is going to make a big difference in cooling costs.

It's not going to change much at all, assuming the AC condenser already there is properly sized, which it is.
That the A/C exhaust fan is not needed is an added

Actually they are air cooled too. They have a properly sized radiator which takes all that heat the water picks up and transfers it to the air.

Have you felt the return line on a modern one, say 14SEER?
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On Wed, 12 Dec 2012 05:24:05 -0800 (PST), " snipped-for-privacy@optonline.net"

Another huge problem is the pool chemistry has to be kept Very Rigidly Controlled or the pool water will rot out the water cooled condenser REAL FAST - or clog it up with scale to the point it won't work anymore, same outcome. Most people can't or won't be that anal about the pool water, and the condensers can rot in a year or two.
This is why water cooled condensers and the water tower used to cool the water use liberal amounts of some really nasty chemical additives to keep that from happening - and you sure as hell don't want to swim in them. And they still dump a lot of water and evaporate even more on purpose (higher temps) and replace it with fresh every day.
Plus, you need to setup a variable-speed pool pump motor and link the AC to the Pool - and you'll really need a computer to know when to shift between the Water Condenser and the regular air condenser coils on the condensing unit - Or it can't run automatically.
If you go that way, gotta go all the way or don't bother.
--<< Bruce >>--
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"Bruce L. Bergman (munged human readable)"

It's not as huge a problem as you think.
For one, a pool should be kept near neutral.
I have a pool heater and years ago, after 2 years, the water manifold developed a leak. The first thing the pool guy was asking is "did you keep the water near neutral?". I did, but was unable to get any kind of discount on the replacement.
When putting in the replacement, I noticed the interior is coated with plastic. So, there's no water to metal contact.
I've been running heaters for more than 6 years now and I can tell you the water in contact with a heated metal unit does not create any special corrosion problems. A condenser shouldn't be any problem at all.
I'm not sure what all the controversy is.
If this guy had his AC unit near his pool pump he just did what was reasonable. The alternative would be to have a big fan roaring near the pool with hot air being blown around. That's not something you want near a pool.
Using water cooling is going to be quieter and save blower energy. I believe other posters are correct, this won't heat the pool much but it will save energy, be quiet, and not heat the air near the pool.
--
Dan Espen

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You are correct, from my actual experience.

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If you watch the TOH video, the problem was not the AC condenser unit making noise. It did not appear to be particularly close to the pool. The problem was the pool is shady and the homeowner wanted to heat the pool. The side benefit was the alleged substantial savings in AC costs.
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Yep, just watched the video.
The AC unit is right next to the pool plumbing. They mention energy savings and pool heating.
For me, the savings would be noise and the hot air blowing around. Any heat input in the pool is going to be very small. It's going to take a huge amount of hot air to heat that amount of cool water. Better to cut a few of those trees down.
--
Dan Espen

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