DIY window AC Chiller new Version

[WheeloFortune]

nah, i can see where your confusion is coming from though.

a btu is a btu is a btu.

What will vary quite a bit is how efficiently you transfer that energy into cooling. efficiencies will be very differently.

think of it like this, if your BTU is like horesepower in a car. . . you efficiency is like your gearbox. . . so even if you have a 500 horsepower car, you aren't gonna go that fast if you only have first gear. similarly if you have a big powerful AC with big btu numbers, and your fan barely blows, how efficiently is it cooling the air? . . but even if your car is only 110 horsepower, if you are in 5th gear you can go 80 mph. similarly a small power window ac with a working fan is gonna cool better than the bigger one with a crap fan. obviosly the best car would be 500 hp with 6th gear. big chiller, most efficient.

professional chillers cool the res water by pumping it through a radiator core, your DIY puts a radiator in the res. . . which is more efficient? dunno the stats on that one.

but if your method is cheap and it works, and buying a chiller is expensive and it works, hmm. depending on needs, I'd like to try your method.

 

[budlydoright]

nah, i can see where your confusion is coming from though.

a btu is a btu is a btu.

What will vary quite a bit is how efficiently you transfer that energy into cooling. efficiencies will be very differently.

think of it like this, if your BTU is like horesepower in a car. . . you efficiency is like your gearbox. . . so even if you have a 500 horsepower car, you aren't gonna go that fast if you only have first gear. similarly if you have a big powerful AC with big btu numbers, and your fan barely blows, how efficiently is it cooling the air? . . but even if your car is only 110 horsepower, if you are in 5th gear you can go 80 mph. similarly a small power window ac with a working fan is gonna cool better than the bigger one with a crap fan. obviosly the best car would be 500 hp with 6th gear. big chiller, most efficient.

professional chillers cool the res water by pumping it through a radiator core, your DIY puts a radiator in the res. . . which is more efficient? dunno the stats on that one.

but if your method is cheap and it works, and buying a chiller is expensive and it works, hmm. depending on needs, I'd like to try your method.

this shit makes my brain hurt! I totally understand the concepts i just cant make the equations. i kind of look at it more like lumen output vs watts input. a 6000 btu air to air heat exchanger isn't nearly as efficient as a direct contact fluid exchanger. In other words wouldn't the direct contact with water making more it efficient give it a greater capacity to remove heat, thus increasing it's btu rating? even with the same wattage input.

Most of the commercial chillers I have seen have a waterbox with a titanium coil inside that carries the refridgerant. All of the small ones I've seen have surprizingly little surface area on the heat exchanger.

I'll tell you, I ran a 1k a 600 and the equivelent of the hydrogen off of it last round. Ran the water at 65 no problems. Compressor runs very little in the winter and quite a bit in the peak of summer but it never sounded stressed or overworked. Most of the racket these things make is created by the condensation being 'flicked' into the condensor. with no condensation they just purr along quietly. I think everybody has had an experience with a small window unit saving them from a blistering summer. these new ones are energy effecient, incerdibly reliable, cheap and plentiful. I also feel more comfortable running something that I can replace easily and cheaply. They are going to wear out running 24/7 for years be it commercial or homebuilt. when it happens I don't want it to be costly or have to wait while it's on order. What do I do with my grow if I'm down for 5 days? Right now I have a backup unit that can stand in for my chiller or my funky cold medina, I mean AC!

 

[stonewallred]

Just as a note about extending the copper pipes.
Any half-way competent HVAC service tech could do so, except for the matter of security.

Spend about $200 or so bucks at the local community college and anyone with any mechanical aptitude could learn enough to do it and get CFC certified also.

 

[budlydoright]

I have looked into this as well. My feeling is that tampering with the factory unit is trouble. These things have no input valves to recharge so this would have to be added. Yes, very do-able but in my case, it was easier to build a rez to accomodate the chiller than to modify the chiller to accomdate my rez. Plus in keeping with my original goal, if this thing fails, I can have a replacement in the water in an hour.

 

[stonewallred]

I used to fix them for a cheap slum lord back in the day. They make these schrader valve fittings that are just like a refrigerator water supply valve. Bolts to the line set and then puncture a hole with a needle valve.

I did HVAC/R for 20 years, along with industrial and commercial manufacturing maintenance, so my idea of easy is usually different than other folks with stuff like that.

I don't know jack about growing pot, but an idea I had about the chiller was a commercial drink case or old refrigerator. They both would maintain a temp between 33 to 40 degrees with no problem, and would (the commercial drink case would be bigger of course) hold a keg (metal for the heat transfer). Put one of them by your grow room, fill the keg with water and pipe that bad boy in.
Would be cheaper to run than a window unit, plus you could keep a frosty beverage handy for when you are working on the plants. [edit: You could use the old evaporator or condenser out of a window unit or an old car radiator as the coil. Forgot to throw that in there. Damn meds I have to take for pain, instead of the pot that works better has my brain a little slow) end edit]

I guess my leeriness about modifying a window unit is the lines are fragile, especially as they get older (the copper turns hard, for lack of a better term), the evaporator is not designed for submersion, nor is it designed for the job which increases the energy used and decreases the life span of the unit. Plus the size of the fins on an evaporator are smaller than what would be used on something designed for the job. Throw in the heat from the condenser, the proximity of the electrical to water and it just sends that creepy feeling of impending doom up my spine.

It obviously works well for you, as your stuff looks really good, so it might just be my "tech" nature getting in the way.

I just look forward to the day when we can call the local repair or service company and have them send someone over to fix the lights in the grow room without worrying about the law. Or better yet, call the police and report some dude out in the garden trying to steal a plant.

 

[budlydoright]

Yea, you have to be very careful when you run this way, this is true of all water cooled setups.

don't think a refridgerator or drink cooler is designed to have a continueous heat source injected into them. Your almost sure to run the compressor until it fails.

I'm familiar with the schrader valves and have looked into modding the unit. But my whole design here is about fast, easy and accessable. A chiller is going to wear out no matter what brand. Yes, I'm sure a commercial unit will last 2-4 times as long. but if it doesn't or when it does go down. I need a replacement that day. I need to know I will have the $$ for it as well. I can't have a cooling system down for more than 1 day.

this is how I met all of the my needs and my design criteria. I repurposed an AC with the intention of replacing it every year or two. I got to tell you this SOB works great.

I personally could find no other way other than making a 4000 dollar investment in redundant commercial chillers

 

[stonewallred]

If it works, it ain't broke, so why fix it?
Your stuff looks good, and I am positive you have more experience with growing using that stuff than I ever will have.

I wonder what you and some of the other growers here could do with legal growing? Being what I have seen so far being produced with ingenuity and DIY tech, versus being able to have the best commercial stuff available.

Working in secrecy, without being able to use the perfect equipment and avail yourselves of the support legality would bring, like plumbers and electricians and masons, not to mention the having to work out of odd places and take hiding just as much into consideration as producing a good plant, and still you all produce excellent grows. Makes me wonder sometimes.

Good growing.

 

[budlydoright]

I read this quote somewhere "Smoking Weed isn't addicting, growing it is"

It is so true in my case. If it was legal, I probably would do it the same way. I get so much enjoyment out of building, wiring, plumbing, programming, the works. I either have a complete understanding of everypart of my system or I'm working towards that. The only way for me, is do to all of it myself. It is so completely satisfying sitting on my porch smoking a bowl of killer bud that I grew. I no longer have guilt for spending my hard earned money on a weed either.

Anyone can do it and it can be done almost anywhere. There are guys on this site growing inside their old tower PC cases with incredible results. If your thinking about getting into this hobby, don't be intemidated by elaborate setups. It doesn't have to be that way. read some journals and find someone doing something you can directly relate to. There's a wealth of information here and many helpful people who are willing to share their knowledge.

 

[Scruffydss]

If you were to use the window AC to cool a res you mentioned using a cooler and some coils ( saw this on another site for coils Stainless Steel Immersion Wort Chillers ... would those coils work for the res? )


any chance of throwing up a diagram of what that would look like? ... also how would you regulate temp of the res water?

is there a way to regulate the amount of water pumped from the chiller to the res to maintain a set temp? ( a thermostat that controls the pump maybe? )

Thanks in advance

 

[budlydoright]

If you were to use the window AC to cool a res you mentioned using a cooler and some coils ( saw this on another site for coils Stainless Steel Immersion Wort Chillers ... would those coils work for the res? )


any chance of throwing up a diagram of what that would look like? ... also how would you regulate temp of the res water?

is there a way to regulate the amount of water pumped from the chiller to the res to maintain a set temp? ( a thermostat that controls the pump maybe? )

Thanks in advance

no diagram. but yes stainless works great. Just run a pump a circuit out of your chiller rez to the stainles coil in your nutrient rez.

You can regulate the temurature with the pump. there are devices made for this in the reef tank industry.

If all your doing is your rez, you probably don't need this much hp.

 

[Scruffydss]

If all your doing is your rez, you probably don't need this much hp.

Thank you for the response. What do you think I would need for HP to regulate the temp for 100G ( buckets incl res ) or thereabouts?

 

[budlydoright]

I really don't know how to calculate this. the AC chiller would work and will just cycle less frequently. Still cheaper than a 1/8 hp.

 

[budlydoright]

UPDATE DIY window AC Chiller new Version

Well after 2 years of pretty continous use, my chiller has started to contaminate the water with corrosion and rust. Replacing it every year or two is still cheaper and more accesible to me than buying a commercial grade chiller.

during it's use I did do a bit of research and purchased a coaxial heat exchanger. I had it soldered into place today and charged it up. I will be testing it tonight. So my new unit made from the original 100 AC now has a water in and out and can sit anywhere and just have water pumped through it.

I'm fortunate enough to have a friend that could do the install and recharge the freon for free, so I;m up to about 165.00 into this chiller!

Will post some pics soon.

 

[budlydoright]

Here's the coil soldered in. It has been handling 2 1k hps.

Notice the improvised vibration isolation

this same unit has chilled water for 18 months, was used as an AC for 12 mos and has now been converted into a proper chiller. not bad for a wal mart special!

 

[budlydoright]

Well, I'm happy to report that the new heat exchanger in my DIY chiller is outperforming the old one by a pretty good margin.

While this project has gone from a simple DIY, to one that requires quite a bit of technical know how. It still illustrates how easy it is to get into water cooling. I would be fine swapping out a new ac every 12 months for 100 bucks. I'm just always looking for ways to improve things incrementaly and just happen to be able to put this together with little effort. I am putting together another unit as a back up and plan on cutting this one in myself.

It will be my first attempt at brazing high pressure lines. I'll try to do a DIY on it as well.

 

[jb1978]

awesome idea where did you get the heat exchanger?

 

[cryodude]

Budly, is that window mounted? and how noisy is it?

 

[budlydoright]

awesome idea where did you get the heat exchanger?

I found the heat exchanger at a salvage yard. They had a few. New unmounted.

Budly, is that window mounted? and how noisy is it?

It was a window airconditioner but it is not window mounted. It's a little noisy but nothing like a fan. It sounds like a loud freezer.

Most of the noise generated by a window AC (the knocking and clicking) is water being flipped into the condensor to evaporate it. With no condensation that noise is eliminated.

I have also added a digital aquarium controller to regulate the tempuratures. I tied the leadts that went to the thermostat on the AC into the relay on the controller. It controls the compressor, while leaving the fan running.

 

[cryodude]

Budly,

That is awesome home cooking man. I may look into something like this. How much power does that critter pull if you don't mind me asking?

 

[budlydoright]

Budly,

That is awesome home cooking man. I may look into something like this. How much power does that critter pull if you don't mind me asking?

It's 4.5 amps. I only run it when the lights are on. Lately the water goes up to 75 when the lights and chiller are off. I run the water 68-78 depending on how warm I'm runnng the box. Usually shoot for 5 degrees colder than the air inside.

It can pull 50 gallons of water down 5-7 degrees in 20 minutes with 2 hot 1k lamps running. It could handle 4k with 100 gallons but it would likely run 90%
of the time. This can scale up quite easily as well. Just get a 1 ton AC unit and a 1ton coil. Same process.

The coil in the unit pictured is straight copper. so it is only good for salt free water. The second one is some fancy nickel linning that claims to be ok in salt water.