EcoRenovator - View Single Post - Bayou cooled (open loop) water source air conditioning?

jeff5may · 07-02-13, 08:49 PM

Ok, so I see you've decided how to do this project. You're going to draw well water to feed your condenser and discharge it into the bayou. For heat exchange, you plan on doing a tube-in-tube or tube-in-shell design. You plan on keeping the capacity under a ton (12kbtu) for each unit and you're not combining compressors for some kind of multi-capacity staging. You may hack multiple units, but each will have its own supply of cool water from the well. Am I right?

To address your concerns about the condenser, a single tube or coil of copper inside plastic will do fine. You're not going to melt or burn up pex or pvc pipe with a half-ton compressor unless you lose your water jacket. The compressor would surely trip out on its own overload many times before the discharge line got hot enough to melt anything. If in doubt, just use iron pipe.

The only real choice to make in the condenser design is the length. If you can deal with a big loop, you can use 1/4 inch annealed refrigeration tube (don't get icemaker line) inside 1/2 inch pex and just make a couple of large loops. If you need something short, you can wind the copper into a coil and put larger pipe around it. For 15 feet of 1/4 inch tubing, this is way more than a ton of capacity with any substantial amount of water flow. What comes to mind here: using a 3/8" iron pipe as a form, the coil would fit inside a piece of 1-1/2" pipe 3' long; using a 1" pipe as a form, the coil would fit inside a 2" pipe 18" long.

If you were planning on a larger (~20kbtu or more) condenser, a more elaborate condenser (with better flow and heat transfer) would be needed to get ultra-high efficiency. Lucky for you, because your setup is small enough to be simple.

TX valves can be found cheap every day on ebay, here's one today:

1 ton (12k btu)
http://www.ebay.com/itm/AAS-1-HC-Eme...item35c9359d0b

You can also surf to surpluscityliquidators.com and find everything you might need cheap.

They have a 1 ton turbotec coax coil for $31.00 today:
http://surpluscityliquidators.com/vi..._TON_COAX_COIL

07-02-13, 08:49 PM	#27
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Ok, so I see you've decided how to do this project. You're going to draw well water to feed your condenser and discharge it into the bayou. For heat exchange, you plan on doing a tube-in-tube or tube-in-shell design. You plan on keeping the capacity under a ton (12kbtu) for each unit and you're not combining compressors for some kind of multi-capacity staging. You may hack multiple units, but each will have its own supply of cool water from the well. Am I right? To address your concerns about the condenser, a single tube or coil of copper inside plastic will do fine. You're not going to melt or burn up pex or pvc pipe with a half-ton compressor unless you lose your water jacket. The compressor would surely trip out on its own overload many times before the discharge line got hot enough to melt anything. If in doubt, just use iron pipe. The only real choice to make in the condenser design is the length. If you can deal with a big loop, you can use 1/4 inch annealed refrigeration tube (don't get icemaker line) inside 1/2 inch pex and just make a couple of large loops. If you need something short, you can wind the copper into a coil and put larger pipe around it. For 15 feet of 1/4 inch tubing, this is way more than a ton of capacity with any substantial amount of water flow. What comes to mind here: using a 3/8" iron pipe as a form, the coil would fit inside a piece of 1-1/2" pipe 3' long; using a 1" pipe as a form, the coil would fit inside a 2" pipe 18" long. If you were planning on a larger (~20kbtu or more) condenser, a more elaborate condenser (with better flow and heat transfer) would be needed to get ultra-high efficiency. Lucky for you, because your setup is small enough to be simple. TX valves can be found cheap every day on ebay, here's one today: 1 ton (12k btu) http://www.ebay.com/itm/AAS-1-HC-Eme...item35c9359d0b You can also surf to surpluscityliquidators.com and find everything you might need cheap. They have a 1 ton turbotec coax coil for $31.00 today: http://surpluscityliquidators.com/vi..._TON_COAX_COIL Last edited by jeff5may; 07-02-13 at 09:37 PM.. Reason: info