How to Heat a Swimming Pool with an Air Conditioner | Ask This Old House

all right so here is your pool filter system it's a pretty standard package you've got two lines that come from the skimmers at the pool right here and they come together to go through this leaf strainer to catch any leaves now right here is the pump that's going to push water through the strainer and right through this cartridge style filter right here now the water gets filtered and then it returns back to the pool right here now at the same time you've got the refrigerant lines right here for your air conditioner and these this is going to have hot refrigerant we want to get the heat energy from that pipe actually into the water that's down inside here so for that there's a pretty ingenious invention it's actually a heat exchanger made exactly for this reason you can see right here that the water from the pool will come in through a pipe right here that'll go down to the bottom of the cannister the pool water will leave through this pipe and go back to the pool itself there's a couple of refrigerant lines right here and what you can't see is actually a coil that's down inside this canister it's made out of titanium that hot refrigerant goes through that titanium coil it transfers the teeth of the pool water now that does a couple of things one is going to heat the pool water which is great for you but it also is going to make the air conditioner run more efficiently great all right so our plumbing connection is going to start with the pool water connections to our heat exchanger I've cut away the existing PVC now this system needs to be able to monitor the temperature that's in the pool so our first fitting is going to be this T fitting right here you can see there's a threaded adapter right there into it I'm going to install this sensor well now the sensor well will allow me to put a sensor down into the well from this side but you can see it will make perfect sensing of the water temperature right there that T is going to go right here I'm going to dry fit all this stuff right now when I get it right we'll go back and glue it all together so this comes right here and there'll be a union connection right there all right now in this side we have a two-inch coupling right here and now we have another elbow and another half of a union right here now once we bring this together so now you can see the path of the water leaves the filter goes by the sensor goes down into the heat exchanger the heated water leaves from here and goes back to the pool so now we can glue up these fittings I'm putting PVC cleaner and glue on the outside of the pipe and the inside of the fitting I just hold it for about a three count is one so Jim the refrigeration portion is a little trickier business we've got to cut into these refrigeration lines but inside of them to fill with refrigerant that sometimes the liquid sometimes a gas always dangerous so we can't let any of it leak out in the atmosphere so we always have to have a licensed refrigeration tech and that's exactly what Dave Connolly is hey David hello - tell us what you do anything what I'm doing is I'm going to remove the refrigerant out of this air-conditioning condenser the lines and the unit in the house using my recovery machine alright so the recovery machine is actually a vacuum plug that's going to pull pull pull everything out of the system and deposit the tank right here right correct all right sorry see you got what about a hundred pounds pressure on the gauges how long will it take to get everything out of the system this pump probably has to run for maybe an hour - all right let you get to it with all the refrigerant removed Dave could start making the piping connections he'll bend the pipe in the proper configuration dry-fit all the connections and then braise the joints brazing is a lot like soldering but it uses a higher temperature gas and a different bonding material to be able to withstand those much higher temperatures and pressures that come in a refrigerant system so David are we doing good made all my connections pressure tested it to make sure it doesn't leak so we are ready to recharge with refrigerant we are good let's do it now the last component of our system is this a master controller this is going to be the interface between the pool controller right here our heat exchanger with its temperature sensor and the air conditioning condenser right there now it's going to mount or on the outside wall right about over there yep perfect all right guys so all of our connections have been made the plumbing connections right here refrigeration we've got it wired this is a really good time to go over the whole system so now whenever this air conditioner calls it's going to check first the temperature of the pool to see if it needs to be heated if it doesn't then what happens is the basic refrigeration cycle that's always been here that refrigerant comes down here but it does one thing it takes a little detour out through the back you can see it comes right up through here and it goes to this valley freeway diverting valve and in this mode the refrigerant comes right through back to the condenser now that condenser comes on the fan comes on it dumps he taught side just like it always did but if the pool says I need some temperature it'll send a signal over here and then this valve will close this port and instead the refrigerant will come straight through right here it's a hot gas right now coming through here coming through here down through this heat exchanger it's going to heat up the pool water right here become a little bit cooler out here go back into the house picks up more heat in the cycle continues so now with this all connected you're going to pay the same amount for electricity for the air-conditioning as you always have but you're going to pay nothing to heat that pool yours well that sounds great to me Richard that seems like the perfect solution for this shady backyard I think it is thank you very much well the thanks goes to you dick thanks for your good work thank you gotta say Richard that's really cool new technology well it's pretty cool but it's not exactly new in the commercial refrigeration world they've been doing this for years you walk into a supermarket and what do you see you see a bank of freezers well somewhere in that building all the heat that they took out of those freezers is being dumped somewhere and they've been able to creatively reuse that to their advantage I don't see a lot of swimming pools in supermarkets no but you can actually take that heat and you can use it to heat other parts of the building or even heat hot water for Falls so it seemed like the installation was actually pretty straightforward I mean you had the air conditioning equipment next to the pool equipment just make the connections it worked out great where it was geographically but it's not as easy it might look you got to make sure you have a good refrigeration tech to be able to do those refrigeration connections you got the electrical to do so that might need an electrician and you also might need the pool guy so there could be three different jurisdictions that have to help up right the thing is though it is so efficient such a smart way to do it what I dream about is actually a condenser that you could buy that would have everything built right into it and just run the two lines to the pool and be done with it yeah yeah that's free it is free and you've got some interesting drain i'm have trouble with that yeah weird so until next time I'm Kevin I'm John still I'm Richard lui and I'm Roger cook for ask this old house weird I'm not that way I'm not no no I dream I dream I do

Channel: This Old House

Views: 1,004,551

Rating: 4.8657236 out of 5

Keywords: This Old House, Ask This Old House, DIY, Home Improvement, DIY Ideas, Renovation, Renovation Ideas, How To Fix, How To Install, How To Build, Swimming Pool, Air Conditioning, Do It Yourself, HVAC, Water, Hobby Heat Home Repair Construction, Plumbing, Plumber, Richard Trethewey, Tom Silva, Norm Abram, tom silva this old house, tom silva house, tom silva construction, tom silva tools, tommy silva

Id: J7fB8ul9dZw

Length: 7min 26sec (446 seconds)

Published: Thu Dec 31 2015

Reddit Comments

[u/HVACGuy12]

It's pretty cool

[u/mrtylah1]

Might work ok. Its basically gonna subcool your liquid line. Not too efficient to heat cold water though. Liquid line is not as hot as discharge line.

[u/Strings-]

It might be better to have the liquid form the "pool condenser" return to the receiver, like it would from a normal condenser, also how it was done it does not go though the filter.

A few things to consider before installing this:

• Is there enough pressure to drive the refrigerant without creating "flash gass"

• If it is going to take 100% of the load, It needs to be able to remove as much heat as the other air condenser

• Refrigerant always collects in the coldest container, I'm guessing this is colder than the receiver and might cause issues, also might be solved by one way valve.

• Probably more stuff to consider

Prediction:

This thing is probably going to be a pain to a lot of people, who are then going to give up and disconnect it from the system.

and some people will save some money (enough to recoup investment???)

[u/mrtylah1]

Ok. That makes more sense. I thought that line was tge liquid coming off the condensor. Although thatv would be pretty cool to subcool the liquid say in arizona wgere i am.

[u/DirtyMud]

It’ll work, you can get purpose built condensors for pool heating. Works the same way this does but it’s all built inside a regular residential style condensor with the pool lines on the side of the unit instead of refrigerant lines.

[u/soltaro]

Very cool, if you have the pool pump located right next to the condensing unit.

[u/WreckedEmRanger]

Have head pressure controls and it'll be fine. Know 2 people who have done this.

[u/RfgtGuru]

It’ll work. It works all over the planet. Nothing new.

ThermaStor has been doing it in supermarkets for years. Hot Spot has been doing It in the residential world for a long time.

Remember, our world of refrigeration and HVAC is all about Heat Exchange.... moving heat from here to there. It’s formally called ‘Heat Recovery’.