Water Cooled Grow Rooms

budleydoright said:

If your going to do any brazing recharging on a window unit. Build one of like this. This is a window AC with the evaporator replaced with a direct to water coaxial coil. You can even buy them with stainless steel coils although they are very expensive. I was getting ready to test the salt water version, which should be usable with nutes but am no longer using a chiller. Paid less than 50 bucks for 2 of the coils at a surplus yard.

I ran 3 fresca sols with 600 hps off of this 100 window unit from wal mart. I could bring 50 gallons down to 50-60 degrees quite easily with this load.

I has a friend in the appliance repair biz do mine. took him 30 minutes. He brazed in schrader valves while the unit was charged, sucked all of the refrigerant out. Cut the new coil in and recharged it.

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+REP for a sweet DIY pic! Nice Budley.

phillipchristian said:

+REP for a sweet DIY pic! Nice Budley.

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fucking a sweet helps to have friends

budleydoright said:

If your going to do any brazing recharging on a window unit. Build one of like this. This is a window AC with the evaporator replaced with a direct to water coaxial coil. You can even buy them with stainless steel coils although they are very expensive. I was getting ready to test the salt water version, which should be usable with nutes but am no longer using a chiller. Paid less than 50 bucks for 2 of the coils at a surplus yard.

I ran 3 fresca sols with 600 hps off of this 100 window unit from wal mart. I could bring 50 gallons down to 50-60 degrees quite easily with this load.

I has a friend in the appliance repair biz do mine. took him 30 minutes. He brazed in schrader valves while the unit was charged, sucked all of the refrigerant out. Cut the new coil in and recharged it.

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Ditto on the Kudos! Two questions, First, why do they call the coils "Coaxial" and second Is "Schrader Valves" a brand name or a trade name for the recharge ports? If it's a brand name then what is the trade name for the valves? I don't want to look like a complete idiot when I go to the HVAC suppy house. Thanks again!

In geometry, coaxial means that two or more forms share a common axis. So the tube in the tube qualify.

Tire valves are schrader valves. I believe it is a generic term now. They come in various sizes.

You want a braze in access port saddle. I've attached a picture of one, however the ones I have used are solid. The schrader doesn't thread into the saddle. You can braze the saddle onto the copper line, pierce and seal it at the same time.





This is what my coil looked like before install.





Here's a used coaxial exchanger I just found on ebay for 100 bucks. 1.5 HP. Slap this into a 18k window shaker from wal mart and you've got a 1.5 hp chiller for about 600 bucks. Do it for less with a craigs list AC. I just bought a year old 18k LG window shaker for 150 bucks!

Probably be easier to do with R22 which is no longer used. I understand the newer refrigerants are "Blends".

budleydoright said:

In geometry, coaxial means that two or more forms share a common axis. So the tube in the tube qualify.

Tire valves are schrader valves. I believe it is a generic term now. They come in various sizes.

You want a braze in access port saddle. I've attached a picture of one, however the ones I have used are solid. The schrader doesn't thread into the saddle. You can braze the saddle onto the copper line, pierce and seal it at the same time.


View attachment 2107303


This is what my coil looked like before install.View attachment 2107305



View attachment 2107306

Here's a used coaxial exchanger I just found on ebay for 100 bucks. 1.5 HP. Slap this into a 18k window shaker from wal mart and you've got a 1.5 hp chiller for about 600 bucks. Do it for less with a craigs list AC. I just bought a year old 18k LG window shaker for 150 bucks!

Probably be easier to do with R22 which is no longer used. I understand the newer refrigerants are "Blends".

Click to expand...

The port saddle looks to me like they operate just like a fitting I used to attach a water line from the ice maker of my fridge to household water line main only brazed into place. I understand now about the coaxial coil looks like ones embedded next to the other (Side by Side). Could you explain a little bit further on the exchanger? It looks to be a coaxial unit also. I have the AC unit on hand 10,000 btu new only used one season. I just need the hardware, the coil and exchanger. I think I can pull this off. Starting my online hunt for the parts. Thanks again!

budleydoright said:

If your going to do any brazing recharging on a window unit. Build one of like this. This is a window AC with the evaporator replaced with a direct to water coaxial coil. You can even buy them with stainless steel coils although they are very expensive. I was getting ready to test the salt water version, which should be usable with nutes but am no longer using a chiller. Paid less than 50 bucks for 2 of the coils at a surplus yard.

I ran 3 fresca sols with 600 hps off of this 100 window unit from wal mart. I could bring 50 gallons down to 50-60 degrees quite easily with this load.

I has a friend in the appliance repair biz do mine. took him 30 minutes. He brazed in schrader valves while the unit was charged, sucked all of the refrigerant out. Cut the new coil in and recharged it.

Click to expand...

Another Question,

How are you monitoring and controling the output temp of the waterlines? Stock control with an inline temp gauge?

Sorry for back to back posts but I'm getting excited!

Hucklberry said:

The port saddle looks to me like they operate just like a fitting I used to attach a water line from the ice maker of my fridge to household water line main only brazed into place. I understand now about the coaxial coil looks like ones embedded next to the other (Side by Side). Could you explain a little bit further on the exchanger? It looks to be a coaxial unit also. I have the AC unit on hand 10,000 btu new only used one season. I just need the hardware, the coil and exchanger. I think I can pull this off. Starting my online hunt for the parts. Thanks again!

Click to expand...

The exchanger is a copper tube, that has a steel jacket around it. There is a space between the two tubes which has a spiral twist to it. Refrigerant flows through this space, while the water flows through the copper tube. They can come in many sizes and shapes, and are often designed (like the ebay one) to wrap around their supporting components. So the 2 exchangers pictured are both coaxial, one is spiraled, the other is C shaped. I refer to the coil and exchanger , they are both the same.
If I remember correctly, you can oversize the compressor and condensor quite a bit since the water is such a good conductor.

Now picture this, take the condensing coil (hot) out of a window shaker and replace it with a coaxial heat exchanger. You now have a water cooled air conditioner! You could heat the water in a hot tub nicely.

I have the rough plans on how make a heat pump that will chill water and warm the air or warm the water and chill the air at the flick of a switch.

Added about 300 bucks in parts to the build, but what a sweet appliance to have in your arsenal. Perhaps I'll get to it someday, I have an extra coaxial coil and window shakers kicking around.

Hucklberry said:

Another Question,

How are you monitoring and controling the output temp of the waterlines? Stock control with an inline temp gauge?

Sorry for back to back posts but I'm getting excited!

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Another Ebay find 25 bucks. i pulled the 2 wires that ran into the analog temp controller ran them into the relay on the controller. this way the controller only turns the compressor off, both exchangers still have power running them (fan/pump). It also has a compressor delay which is required. Only reads in celcius though.

and please don't sweat the posts, keep em coming. I'm pretty certain PhillipC's open to as much information in this thread as can fit! I spent lot's of time f'n with this stuff and enjoy sharing my experience.

Also, they make clamp on schraders for refrigerant almost exactly like the swamp cooler ones, just heavier duty. I was advised against their use. I was told they ALL eventually seep.

DIY but do it right!

God damn Budley!! You are like McGyver.

phillipchristian said:

God damn Budley!! You are like McGyver.

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But didn't McGyver save the world a couple times.

To me my growroom is the world!

It's funny looking at how my kit evolved. started with a 1k in a cool tube air cooled, went to fresca sol and 100 gallons. Needed chiller instantly and didn't have the scratch or desire to spend so i made one out of an AC just by submerging the evaporator coil in the rez. Instant chiller. added a second fresca sol and then a third in a larger space have run a 6k and an 8k window shaker with the frescas. did 2 x 1k then 3 x 600. Setup a watercooled co2 burner utilizing a 100.00 propane water heater but had to quite using it, it put out too much too fast.

Now I have gone from a large box, to a room. I decided to go open hood. It is a 8 x 11' space with 8ft ceilings. I have 2 1k's and 2 600's. I'm on the fence on running 4-1ks or 6 or 8 600's. If I go 600's I'll have to go vertical bare bulb, as there wouldn't be room for that many hoods! Scored the 18k AC off of craigs list for 150. One season old. not enough for 4 k in the heat of the summer so I may drop to 3k.

Really liked the quiet that w/c brings to your room. I hate all of the fan noise and ducting. My current setup isn't to bad, the whine of the air cooled hoods makes it less than a tranquil experience IMHO. I like to sit and stare and toke and get lost in the dream!

sub'd to keep track of the thread.

DIY water cooling now, and i am looking to go way out of the box in the next few months. I'm glad i found this thread.

Doer said:

"I like to sit and stare and toke and get lost in the dream!"

We who stare at weed, salute you!

Watercooling is the way to go. Stick the AC coils in the water. Yep. I just used hose parts and a no-flo/no go sensor from Dwyers Instruments for $40.

What do you use for flow sensing?

This summer, I will be experimenting with min-cooling tower set up in the bottom of the dis-used hot tub. Very dry around here, so that should work for 1/2 of
the time. It's a plumbing problem and needs a lot of check on at first. But now, it just runs.

What do you use for filtration and sterilization of the cooling water? I had a lot of problems till I sorted that out.

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Hey Does, thanks for stopping by and Welcome!

The chiller I have has a built in digital waterflow sensor on both reservoirs with an automatic shutoff if flow rates drop below a setpoint. Since they are sealed systems all I have to do is add 25% propylene glycol to the water in the reservoirs and there is no need for filtration or sterilization. I use R/O water and change out the water usually once a year.

I see. I ended up borrowing an idea from outdoor ponds. Lava rocks support healthy biota that keeps the water polished well and I have a big filter bag over the sump pump. Water returns thru the box of rocks.

"Refrigerant flows through this space, while the water flows through the copper tube."

Counterflow cooling. This reminds me that a great source for this, good prices, etc, is the homebrewer DIY community.
The wort must be chilled very quickly past a certain temp, or bacteria will take over.

The backyard guys will braze a 6 ft tall, 2 ft across coil, if that's your need. Immersion or counter-flow.
Need SSRs for failsafe relays? The backyard cooker, oil fired heat...all the DIY stuff is cheaper.

This is a hellova thread. I have seen only one reference to a geothermal concept. Is the 55F water not cold enough to do much? I'm looking at 3000w to cool in a basement. I could bury coils easily. Seems like such a "green" thing to consider.

Rrog said:

This is a hellova thread. I have seen only one reference to a geothermal concept. Is the 55F water not cold enough to do much? I'm looking at 3000w to cool in a basement. I could bury coils easily. Seems like such a "green" thing to consider.

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Hey Rrog, welcome. There is a BUNCH of DIY chiller and geothermal info in the thread. Maybe some of it got erased with the hack last month.

Need more info on exactly what you plan on doing with these coils. Are you going to be using them to cool a chiller reservoir? Or are you just going to run coils in the ground recirculating through your room? What are you hooking the coils up to; heat exchangers or water cooled equipment? Can't really comment on whether your idea will work or not till I can see what type of load you are putting on it.

Hello phillipchristian,
This is a very interesting thread. If a person wanted to try geo thermal, what would be better to bury - coils, a holding tank, or runs of pipe ?

Rrog said:

This is a hellova thread. I have seen only one reference to a geothermal concept. Is the 55F water not cold enough to do much? I'm looking at 3000w to cool in a basement. I could bury coils easily. Seems like such a "green" thing to consider.

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55 is the right temp. i thought we had talked about geothermal heat sinking before, but i guess not.

I have thought about adding a geothermal unit to my cooling (I'm building a house that has a geothermal heat sink compenent, w/ passive solar and wind), but for me, i'm hoping my giant rez burried 10 ffet in the ground will act a s ageothermal heat sink.

great topic, good call.


green hell, its cheaper