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GreenGills



Registered: 10/12/13
Posts: 269
Last seen: 2 years, 8 months
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Grow Room Cooling
#19302603 - 12/20/13 12:05 PM (10 years, 1 month ago) |
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Hello all,
I am new to the Shroomery and want to thank everyone for sharing there experience and wisdom. I started a similar thread elsewhere a few days ago and got nothing so I'm here. I have been looking into cooling options for my grow room that I will be beginning construction on in a few weeks. So I have decided to convert a window AC to a water chiller. I would like to get as many opinions as I can before I commit and see how practical my plan is from someone else point of view. My plan is to have the evaporator from a window AC removed and replaced with a tube in tube coaxial evaporator/condenser coil. I will pump water or coolant through the other tube, thus cooling the water/coolant in my reservoir. At the same time it will pump the water/coolant through an "ICE BOX" or heater core heat exchanger to cool my intake air going into my grow room. I am no expert so sorry if I am not being clear with any of my terms. I have attached a picture of the type of coil and heat exchanger that I plan to use. Any input is appreciated. I am starting a gourmet mushroom business and need effective cooling in the summer. Any advice is appreciated. Thanks in advance.
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Smushroom
Avid Learner

Registered: 02/02/05
Posts: 2,806
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What is the rough size of the grow room?
Are you wanting something outside the grow room cooling intake air specifically or would you have room inside the grow room for a standing unit?
Current room temp?
What temp are you looking to achieve?
How much are you looking to spend?
Would you rather spend less and do more makeshift construction yourself or spend a bit more and get something ready to go?
******
My first thought would be an evaporative cooler. You can get small floor models for $100-200 that can cool a 100-200 sq ft room 10-15 degrees. They would also help to keep the humidity up and several models come with a built in HEPA filter that would help clean the air as well.
My only concern is how well it would work in an already cool-ish and humid environment. I don't think it would be an issue though.
If your grow room is over 200 sq ft you would have to probably get multiple or spring for an industrial model that would be pricey.
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GreenGills



Registered: 10/12/13
Posts: 269
Last seen: 2 years, 8 months
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Re: Grow Room Cooling [Re: Smushroom]
#19302793 - 12/20/13 12:51 PM (10 years, 1 month ago) |
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The grow room is about 12x15 and the unit will be outside of it cooling the intake air only. It gets pretty hot and humid where I am, and it will not take very long for it to over heat the grow room. I wish I could use an evaporative cooler but I don't think it would work too well with the humidity. I could probably get the cost down to 200 or so. I am looking to keep it below 70 degrees in the summer with plenty of air exchange.
The price for an equivalent water chiller (1HP) would be around 1000 or more.
Thanks for the input.
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Smushroom
Avid Learner

Registered: 02/02/05
Posts: 2,806
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I've never disassembled an AC unit so I can't really comment on your idea although it does seem feasible. The only issue I can see with it is efficiency and energy use. Are you planning on still putting it in a window? I feel like bringing in outside air, cooling it, then cooling the water in your coil would be a lot of energy wasted and it might not make the ice box cooler cold enough to cool your intake air. You could also experience condensation problems in your ducting if you are pulling humid air through it and that could lead to possible mold issues.
Have you looked at floor AC units? My friend found an amazing deal for one on craiglists that came from an industrial space that was closing down. Even if it is outside your grow room the room air would be cooler than outside air (assuming your grow room isn't a free standing structure outside). Use that for your design instead of a window unit. Another option would be to put it inside your grow room mounted to the wall. Have the intake on the AC unit connected to outside the room so you would still have plenty of air flow.
I just pulled the chart for evaporative coolers at different temps and humidities and you are right, it wouldn't do enough to get the temps you want at high humidity.
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solarity
mm... my favourite food



Registered: 03/31/09
Posts: 1,590
Loc: UK
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Re: Grow Room Cooling [Re: Smushroom]
#19303278 - 12/20/13 02:48 PM (10 years, 1 month ago) |
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I pretty much did exactly what you are talking about but much cheaper and dirtier!
I took a mobile/portable AC unit (the uk does not have window chillers nor does it have chilled water AC systems)and basically dropped the evaporator (ie the bit that gets cold) into a small tank.
I then circulated the water from a large (1000L)insulated tank through the small tank.
I ran this overnight when the cooling load is low and the electricity is cheaper.
The 1T of chilled water was then pumped through pipes to heat exchangers (ie car radiators!) in the grow rooms positioned in front of the air intake.
This was very ugly but cheap and effective. I did a whole write up on fungi forum about it so if that ever re-appears take a look.
In the US you can probably get a chilled water system cheaper than building one. For next summer I am switching out the hacked AC unit to use "Flash coolers" that are designed to cool beer in-line.
-------------------- Commercial exotics farmer for 8 years - now sold up!
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drake89
Mushroom Magnate



Registered: 06/26/11
Posts: 4,168
Loc: TN
Last seen: 4 years, 10 months
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Re: Grow Room Cooling [Re: solarity]
#19303367 - 12/20/13 03:06 PM (10 years, 1 month ago) |
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If you can, why not just switch up species with the seasons? It's way cheaper than fighting the temperatures. As long as your building has a bit of insulation, like R8 or so, you shouldn't get huge temp swings. That said, ground water may be your friend here.
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GreenGills



Registered: 10/12/13
Posts: 269
Last seen: 2 years, 8 months
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Re: Grow Room Cooling [Re: drake89]
#19304433 - 12/20/13 06:38 PM (10 years, 1 month ago) |
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@Smushroom Condensation will definitely be an issue, I will have to figure out something for that. The floor ac is a good idea. It would be easier to exhaust the heat produced.
@solarity I was thinking about keeping the evaporator that is on the ac but was hoping that the coaxial coil would be a little more efficient. Its good to hear that you had some success with something similar. I will be looking into the flash coolers that you mentioned.
@drake We'll see how it goes with the temperatures, but as of now I am trying to stay away from switching species. My grow room is in my basement and will be insulated, so it may not be as extreme as I expect. We are from the same state so temps should be similar.
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Amanita virosa
botanist by day


Registered: 12/04/11
Posts: 2,458
Loc: north kakalacky
Last seen: 6 months, 17 days
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If the room has a window stick the wind.ow unit right in there rather tht all that experimental modification. Otherwise, we use a portable ac. It cycles on a timer to drop tHe temps during the heat of day. I am with drake on seasonal growing. We run tropical oysters all summer. Running kings and poplars in summer is a waste of money. Shiitake and lions mane will run all year long between 40-80 degrees.
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Smushroom
Avid Learner

Registered: 02/02/05
Posts: 2,806
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How is your basement constructed? Are all 4 sides completely underground or have 1-2 exposed or partially exposed?
If all 4 sides of your basement are below ground level I highly doubt you'll have any issues with temps. If some of the sides are exposed and you have the option build the room against a side below ground.
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Amanita virosa
botanist by day


Registered: 12/04/11
Posts: 2,458
Loc: north kakalacky
Last seen: 6 months, 17 days
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Re: Grow Room Cooling [Re: Smushroom]
#19304791 - 12/20/13 07:44 PM (10 years, 1 month ago) |
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Quote:
Smushroom said: How is your basement constructed? Are all 4 sides completely underground or have 1-2 exposed or partially exposed?
If all 4 sides of your basement are below ground level I highly doubt you'll have any issues with temps. If some of the sides are exposed and you have the option build the room against a side below ground.
Depends on how much mush you pack in there and how hot your intake air is. Our basement grow room is back filled on all four sides but fully packed with bags in summer there is no way we can grow kings poplars namekos etc. without ac. The mush generates its own heat for sure.
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GreenGills



Registered: 10/12/13
Posts: 269
Last seen: 2 years, 8 months
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Re: Grow Room Cooling [Re: Smushroom]
#19305865 - 12/21/13 12:29 AM (10 years, 1 month ago) |
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Quote:
Amanita virosa said: If the room has a window stick the wind.ow unit right in there rather tht all that experimental modification. Otherwise, we use a portable ac. It cycles on a timer to drop the temps during the heat of day. I am with drake on seasonal growing. We run tropical oysters all summer. Running kings and poplars in summer is a waste of money. Shiitake and lions mane will run all year long between 40-80 degrees.
Its looking like I should consider some tropical species. Battling the heat of summer may not be worth it.
Quote:
Smushroom said: How is your basement constructed? Are all 4 sides completely underground or have 1-2 exposed or partially exposed?
If all 4 sides of your basement are below ground level I highly doubt you'll have any issues with temps. If some of the sides are exposed and you have the option build the room against a side below ground.
One side is open and has a window. It is the window that I will be using for my intake and exhaust. The grow room is against the below ground side.
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t3chnobily
Strangest


Registered: 02/04/12
Posts: 651
Loc: As Seen In VT
Last seen: 6 years, 9 months
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Check out sparkles threads on C. indica. Loves the heat.
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GreenGills



Registered: 10/12/13
Posts: 269
Last seen: 2 years, 8 months
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Quote:
t3chnobily said: Check out sparkles threads on C. indica. Loves the heat.
Thanks!
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Aleon
The Power of Our Origins



Registered: 05/26/11
Posts: 1,127
Loc: Everywhere
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We use a window AC to keep our FC in the low 60's in the summer.. I wish I could afford a split ac, which would be ideal.
-------------------- Mushroom medicines available at: www.swordandshieldwellness.com
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GreenGills



Registered: 10/12/13
Posts: 269
Last seen: 2 years, 8 months
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Re: Grow Room Cooling [Re: Aleon]
#19306713 - 12/21/13 07:34 AM (10 years, 1 month ago) |
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How hot does it get in the summer where you are?
I do have the option to route my central air to the grow room. Not sure if it would be enough to keep the temps down in the middle of summer though. I will just have to try it and see.
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t3chnobily
Strangest


Registered: 02/04/12
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Most species will do ok as long as you can get them down at night. I had a great flush off of some old blue blocks in august when it dipped into the 50's one night
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Smushroom
Avid Learner

Registered: 02/02/05
Posts: 2,806
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Actually I just thought of a possible solution for you that would probably cost less per day to maintain than a window CS unit. The caveat would be that it would require regular maintenance to keep running.
Basically you would get a very well insultated cooler and create a recirculating system out of it. You would connect that to your ice box heat exchanger like you were talking about doing. The only electricity needed would be to power a decent aquarium/pond pump which would be a fraction of the electric needed for an AC unit.
Now the fun chemistry part. Instead of circulating water you would circulate a dry ice and ethanol mix. That will maintain a temperature of -78c = -108f degrees until all the dry ice sublimates.
Dry ice can be purchased at most ice cream shops, university science departments, and industrial gas suppliers. You can get it for as little as $1/lb. You would just use everclear as the ethanol source. The ethanol would stay in the system and you would only need to replace the dry ice as needed.
That would have absolutely no problem cooling your intake air to a reasonable temperature. Assuming you have a very well insulated cooler and use the shortest lines possible to circulate the mix (and insulted the lines as well) you would get a very high efficiency in terms of heat transfer.
Now the only question would be how much dry ice you would need and how often you would need to add more. A high end cooler can hold regular ice sealed for 8-10 days in the heat. A dry ice mix would be longer (possibly significantly). However you'll be constantly circulating the cooling mix in and out of it so that will definitely take a toll and would require experimentation.
The smallest high end coolers will hold roughly 20lbs of ice and enough ethanol to circulate. Just estimating off the top of my head I think that this setup could possibly last 5-6 days, maybe more if the rest of your basement is cooled below outdoor temp. If you were to put it on a thermostat or timer and not use it 24/7 then I think it coule potentially last longer.
That comes out to about a $150-300 initial investment and it will cost you about $20-25 everytime you fill it up. Assuming that is just every 5 days that is ~$4 a day, electric use would be minimal. That is probably comparable to a window AC's running costs but this should be a lot more efficient.
*********
Sorry for the extremely long post but I had the idea and thought I should explain it in length.
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GreenGills



Registered: 10/12/13
Posts: 269
Last seen: 2 years, 8 months
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Re: Grow Room Cooling [Re: Smushroom]
#19307243 - 12/21/13 10:16 AM (10 years, 1 month ago) |
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Quote:
Smushroom said: Actually I just thought of a possible solution for you that would probably cost less per day to maintain than a window CS unit. The caveat would be that it would require regular maintenance to keep running.
Basically you would get a very well insulated cooler and create a recirculating system out of it. You would connect that to your ice box heat exchanger like you were talking about doing. The only electricity needed would be to power a decent aquarium/pond pump which would be a fraction of the electric needed for an AC unit.
Now the fun chemistry part. Instead of circulating water you would circulate a dry ice and ethanol mix. That will maintain a temperature of -78c = -108f degrees until all the dry ice sublimates.
Dry ice can be purchased at most ice cream shops, university science departments, and industrial gas suppliers. You can get it for as little as $1/lb. You would just use everclear as the ethanol source. The ethanol would stay in the system and you would only need to replace the dry ice as needed.
That would have absolutely no problem cooling your intake air to a reasonable temperature. Assuming you have a very well insulated cooler and use the shortest lines possible to circulate the mix (and insulted the lines as well) you would get a very high efficiency in terms of heat transfer.
Now the only question would be how much dry ice you would need and how often you would need to add more. A high end cooler can hold regular ice sealed for 8-10 days in the heat. A dry ice mix would be longer (possibly significantly). However you'll be constantly circulating the cooling mix in and out of it so that will definitely take a toll and would require experimentation.
The smallest high end coolers will hold roughly 20lbs of ice and enough ethanol to circulate. Just estimating off the top of my head I think that this setup could possibly last 5-6 days, maybe more if the rest of your basement is cooled below outdoor temp. If you were to put it on a thermostat or timer and not use it 24/7 then I think it coule potentially last longer.
That comes out to about a $150-300 initial investment and it will cost you about $20-25 everytime you fill it up. Assuming that is just every 5 days that is ~$4 a day, electric use would be minimal. That is probably comparable to a window AC's running costs but this should be a lot more efficient.
*********
Sorry for the extremely long post but I had the idea and thought I should explain it in length.
Yeah I thought about something similar once before minus the ethanol. I would have to find a cheap supplier of dry ice for it to be economical. Where I am it would cost about $1.10 per day to run a 550 watt ac for the entire 24 hours (assuming correct math). Thanks a lot for all of your feedback! Its seems that I might have to play it be feel and see how the summer treats me.
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Smushroom
Avid Learner

Registered: 02/02/05
Posts: 2,806
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Regular ice wouldn't cool it enough to get temps down. If you mixed dry ice into water it will either evaporate instantly or freeze the water solid depending on how much of each you use.
Having various dry ice powered cooling inside the chamber could work very well but that would add too much CO2 to the room and push out your O2.
I'd recommend getting an infrared thermometer and measuring the surface temp of all 4 walls of your grow room (floor and ceiling too), temp of the substrate, regular basement temp, outdoor temp, and intake air temp. That may give you a better idea of exactly where you have the most room for improvement
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Amanita virosa
botanist by day


Registered: 12/04/11
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Loc: north kakalacky
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Re: Grow Room Cooling [Re: Smushroom]
#19308133 - 12/21/13 01:46 PM (10 years, 1 month ago) |
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Think simple and practical if your goal is to make money. Grow warm weather strains in the dead of summer and use a squirrel cage blower to suck ur central air in there. Build it into a plenum box so you can throw a filter on it. If your goal is not to make money, there are plenty of fancy complicated solutions.
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GreenGills



Registered: 10/12/13
Posts: 269
Last seen: 2 years, 8 months
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That makes a lot of sense to me. I will be purchasing an Aloha starter pack shortly, any particular warm weather strains that perform well? Thanks.
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