Water cooled heat exchangers vs A/C

[Uncle FREEDOM]

Hey guys been busy working on my new room setup, and was wondering about the different ways to cool the room. I have always just used A/C to cool, but have always wondered about heat exchangers and how they work compared to A/C units.

What are the pluses and minuses of heat exchangers vs A/C?

Can on run a water cooled heat exchanger if one is on a well?

Lets hear your opinions!

peace

 

[Mackawber]

you mean an evaporative cooler right? The kind of unit that you can use in a dry arid hot environment. Air passing through a water soaked membrane/filter saturates the air with moisture as it passes through yielding a cooling effect/temperature drop. You can't use an evaporative cooler in a humid environment, so it has to be hot and dry for it to work. It's also limited in what it can do. The other advantage it offers is energy savings---It doesn't use nearly as much electricity as an AC unit would.

When you say "heat exchanger" I think of a air cycle type AC system---like you would find on an airplane, instead of the vapor cycle type AC system we use in our homes and cars.

 

[riverrat]

I’m putting together such a system right now. I’m using a auto ac evaporator that I’ve mounted a fan on, I will mount it in the grow chamber and pump a salt water mixture through it from a 30 gallon tank I have in a chest freezer close by. I have ran some test with the evaporator and can get output air temps from it of 50F. This was using a ice water bath at about 38F as a coolant. Once I get a decent pump and can set up the freezer, the coolant temps I’m pumping will be in the order of -5F so I think the system will work quite well. I’ll post pics soon. I ran outa money and have to wait to next payday to buy the pump I need.

RR

 

[riverrat]

Here is another recent post I made on the subject:

Here is how I’m solving my heat problems. I have 2 HID lights one is a 600 and the other is a 400. I have enclosed them in a box with a sealed glass bottom. I’m using a 6 inch Can-Fan to draw air through the box. With the grow chamber sealed, my temps are running about 88-90 F. My grow is in an attached garage has to be very stealthy. My Can-Fan is up in the attic and far away so I don’t have much fan noise in the garage, but I’m am working on air flow noise. Anyway 90 F is too hot for my liking. ( I want 70 F) and I’m in a rental house so I can’t cut a hole in the outside wall and install an A/C. It would be too noisy to install in a box inside the garage and I’d have to deal with the water condensing from it.
I’m using 6 computer type 4 inch fans rated at 130 CFM each to pull through my filter system and circulate air around the sealed grow chamber. I haven’t added CO2 yet, but that’s next to add after I get a couple of grows done. Anyway, what I’m putting together now is a water cooling system for the grow chamber consisting of a , used auto A/C evaporator coil ($1.00 on EBay),and a used 8 cf. chest freezer off Craigslist ($50.00) . My plan is to put a tank into the chest freezer containing about 15 gal. of a coolant solution, then circulate that 0F or colder solution through the A/C evaporator coil installed in the grow chamber which has air sucking through it from the fans. I have the parts and have run some preliminary test using a ice water bath and have gotten output air temps from the coil down to about 50 F. So I’m pretty sure once I get the freezer plumbed and filled with coolant, the system will work great.
The freezer is very quiet and looks natural in the garage. I haven’t decided on what I’m going to use as a coolant solution yet. I have a source for ethylene glycol but that stuff is toxic and I don’t want it in the freezer where I will also have food. I could use propylene glycol which is non toxic but cost about $25.00 a gal. and I’d need about 10 gal. of the stuff so cost is too high for that. I think I’m going to settle on a salt brine solution which is cheap and effective but will likely corrode up my aluminum evaporator over time. Anyway if you decide to try something like this, make sure you get a evaporator that has the plastic drain housing because water will condense off that evaporator. I drain mine back into the reservoir. Also be very careful cutting holes in the freezer for the piping. Freezers have the cooling coils wrapped around the sides and if you cut into one you will ruin the freezer. I’ll keep you posted on how well it works once I get all the parts installed. I’ll put up some photos of the grow in a few days, I got 2 Blueberries and 2 White Widows about 2 weeks into flower right now and looking forward to my harvest in about 6 weeks. I had to shut my old grow down and move a couple months ago and I’m down to nothing but left over trim to smoke. So you guys know what my weekend project is. I’ll post next week on how it is all working.

RR

 

[Bozo]

I recently built a heat exchanger for my water cooled co2 gen.I used a ford heater core and built a box with 4 inch inlet and outlet .It scrubs 100% of the heat from the exhaust .If you used a radiator from a car and ran large amounts of cold water through it with fan blowwing through it you could do some damage to the heat .cold liquids running through lines in warm room condensate like crazy watch out for drips in electrical equipment

 

[Uncle FREEDOM]

ok when i mean water cooled heat exchanger i am not talking about a evaporative system. I mean a system that acts like radiator for a car.....

like this.....

http://www.progressive-growth.com/proddetail.php?prod=heatexlb


Just looking for info as the pluses and minuses of the coolers vs A/C. (like how much water they use, and if they would be too much strain on a well (i have never had a lack of water, in my well but never pushed it))

Just curious as to how they stack up.

thanks for the replies.

 

[riverrat]

Here are some pics of the evaporator I using. This is from a Sabb I think. You see the cooling water lines running into ther housing.



Here is the back of the evaporator with the fan mounted.



Photo of my shop/growroom. ( more later)



Freezer I'll be using to cool the saltwater coolant.

 

[THCV]

ok when i mean water cooled heat exchanger i am not talking about a evaporative system. I mean a system that acts like radiator for a car.....

like this.....

http://www.progressive-growth.com/proddetail.php?prod=heatexlb


Just looking for info as the pluses and minuses of the coolers vs A/C. (like how much water they use, and if they would be too much strain on a well (i have never had a lack of water, in my well but never pushed it))

Just curious as to how they stack up.

thanks for the replies.

hey freedom-

heat exchangers are for people who have lots of cold water. if you have your own well, it might be ideal. it uses a lot less energy than ACs for the same cooling power, but uses lots of water of course. anyone with cheap, cold water and a decent way to get rid of all that hot water should go for it, IMO. Where I live, electricity is the cheaper and more environmentally sound choice for cooling, but if you look at the videos on urbangrower. com it seems like most canadians use these chillers to great effect.

i have a fantasy of having a well, and using the ice cold, free water to handle chillers, water-cooled lights and water-cooled CO2. But for now, i do it all with AC, fans and electricity and it works.

Note that if your water isn't cool in the summer, it won't work as well. So well water at a year-round 60 degrees is a lot better than the variable seasonal temp of the muni supply--a heat exchanger running on muni water in a heat wave will be useless.

THCV

 

[Uncle FREEDOM]

Hey THCV thanks for the reply....


I guess my concern with the water cooled heat exchangers is that in the winter (when no water is flowing down through the soil) that i might run out of water. I might be paranoid, but it is a concern....

Maybe i will buy a portable a/c too and have it as a back up (would hate to get caught with no cooling!) LOL

Does anyone have any ball park figure as to the real world flow rate of these heat exchangers??

Thanks again boys

peace

 

[Uncle FREEDOM]

New idea popped in my head, what if i laid the pipe in my yard (i have a multi acre property) and constructed a geothermal cooling loop. Could i just hook this up to a pump and a water cooled heat exchanger???

I would do this because:

A to avoid stressing the well
B after grow is done, i can convert my house into geothermal heat/cool (raising the value)

Anyone have experience with this??

 

[Pandemic]

I always called them heat exchangers too. The big radiator looking units with fans that are as big as I am on commercial buildings.... I coulda sworn


Anyway, nothing useful to say just two good links.

Heat exchangers - http://www.heatexchanger.ca/

Underground A/C loop (free a/c) - http://mb-soft.com/solar/saving.html