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View Full Version : Please Help!! Question about Heat removal from a "Sealed" room



loopup2u
01-14-2011, 08:04 PM
OK, so I have this small area that I am turning into a grow room, the total area of the room will be around 250 cubic feet. The area that will be usable for the grow will be closer to 165 Cubic feet. The room will be completely sealed for the benefit of Co2 Enrichment via pressurized tank/regulator. As far as heat producing devices we are only talking about 1000 watt HPS, and probably 600 watts T5. A guess would place that pretty close to 5,000 BTU's when they are all on.

What are my best options for keeping things cool?

I noticed that all portable A/C units have a venting tube to cool the device. (Venting Atmosphere from the room is what I am trying to avoid)

How viable is running a portable evaporative cooler in combination to a dehumidifier? (Take into consideration where I live, year round has a relative
humidity of 50%-65%)

I saw there are those small split system A/C, but the ones I have seen start around $1,200. And that would strain my budget a little too much.


Any Ideas? Advice?



Thank you

keylime
01-14-2011, 08:39 PM
Well, I've been in the HVAC business for 10 yrs and can tell you what I would do. Assuming you have an outside wall, I would install a "window shaker" air conditioner that vents to the outside. 8,000 to 10,000 BTU is what I would prolly put in there. I would also get a dehumidifier that I could run if I didn't need too much cooling, although just running the dehumidifier will also keep the temperatures down somewhat... because its basically a partial air conditioner if you like.

keylime

loopup2u
01-14-2011, 09:41 PM
Keylime,

Thank you for your reply. Unfortunately, the room is in the garage up against a concrete filled cinder block retaining wall that has earth on the other side of it.

keylime
01-14-2011, 09:56 PM
Keylime,

Thank you for your reply. Unfortunately, the room is in the garage up against a concrete filled cinder block retaining wall that has earth on the other side of it.

Well then, my second choice would be one of those mobile air conditioners with the exhaust hose....as long as it can be vented out of the area... even up thru the ceiling if necessary.

keylime

loopup2u
01-14-2011, 10:58 PM
OK, then here is my question to you, do those Portable units with the exhaust hose, pull air from the room to exhaust the heat from the unit?

My concern is that it would vent the Co2 out. Another concern is that it would vent smells if it does indeed pull air out of the room.

keylime
01-15-2011, 12:14 AM
Well those are legitimate concerns.... but nothing is perfect. You could set up the exhaust and dump it thru a filter first. There is no way to get around the CO2 loss, its prolly minimal. The only answer I would have is have timers running so that when one is running the other is not.

keylime

loopup2u
01-15-2011, 01:01 AM
It looks like that is probably what I will end up doing. Just to repose the question. Do you think a portable evaporative cooler could give me the cooling I would need if it was run in tandem with a dehumidifier?

keylime
01-15-2011, 02:47 AM
It looks like that is probably what I will end up doing. Just to repose the question. Do you think a portable evaporative cooler could give me the cooling I would need if it was run in tandem with a dehumidifier?

An air conditioner works by removing moisture from the air. When you have a dehumidifier working at the same time as the A/C, it is helping the A/C do some of its work.... and it won't have to work as hard to do its job.'


keylime

WashougalWonder
01-15-2011, 02:10 PM
An air conditioner works by removing moisture from the air. When you have a dehumidifier working at the same time as the A/C, it is helping the A/C do some of its work.... and it won't have to work as hard to do its job.'


keylime

Well for an HVAC, I wonder how you come up with it works by removing the moisture. To the best of my knowledge the frost is a byproduct of the evaporator freezing the moisture in the air passing over it. The actual cooling is done by the refrigerant in the device trapping it in the refrigerant and exchanging temps by ambient air passing over the condenser an evaporator. Are you licensed HVAC?

You seem to have a thing for humidifers too....They do fine.

Now, I would just vent with fan to outside the grow room. Turn off fan during c02 dispersion,which I think is a real waste of money for the bother involoved.

GaGrown
01-15-2011, 03:46 PM
Being an HVAC, Master sheetmetal mechanic. I have seen 1st hand that an air conditioner in a window will raise humidity. Hot and cold air meeting you get condensation on the walls and anything metal or plastic.Making the risk higher to aquire an airborne mold or mildew. The best senario would be to use only the dehumidifier and draw air into your room with a passive vent with a backdraft damper.You keep your sealed room aspect. Use a scrubber and a dehumidifier.

keylime
01-15-2011, 11:09 PM
Being an HVAC, Master sheetmetal mechanic. I have seen 1st hand that an air conditioner in a window will raise humidity. Hot and cold air meeting you get condensation on the walls and anything metal or plastic.Making the risk higher to aquire an airborne mold or mildew. The best senario would be to use only the dehumidifier and draw air into your room with a passive vent with a backdraft damper.You keep your sealed room aspect. Use a scrubber and a dehumidifier.
I copied the following from:
How air conditioners work (http://www.essortment.com/all/airconditioners_rutx.htm)
There are three main kinds of air conditioning systems. Summer air conditioning will clean, cool, and get rid of moisture from the air. Winter air conditioning will clean, heat, and add moisture to the air. Year-round air conditioning will clean and control the temperature and the amount of moisture in the air throughout the year.

With a sealed room, it will (or should) be only "summertime" in there while the lights are on.

keylime

GaGrown
01-16-2011, 03:00 PM
I copied the following from:
How air conditioners work (http://www.essortment.com/all/airconditioners_rutx.htm)
There are three main kinds of air conditioning systems. Summer air conditioning will clean, cool, and get rid of moisture from the air. Winter air conditioning will clean, heat, and add moisture to the air. Year-round air conditioning will clean and control the temperature and the amount of moisture in the air throughout the year.

With a sealed room, it will (or should) be only "summertime" in there while the lights are on.

keylime

But,if you use an air conditioner in the winter it won't work that way! It works in an opposite fashion. Esspecially when there is an HID lamp fixture in operation. Just think about it... When you walk outside,in winter and breathe and blow your breath out you create condensation in the air. Same thing happens on a smaller scale but moisture still accumulates.

My room is a sealed room too. Not using co2 at the moment,but it is ready for it to be used..

keylime
01-16-2011, 04:37 PM
You don't need an air conditioner in the winter. Air conditioning will only be used when it gets too warm in the room.

GaGrown
01-16-2011, 04:53 PM
You don't need an air conditioner in the winter. Air conditioning will only be used when it gets too warm in the room.

That would be why you have an exhaust fan and a passive intake vent with a damper. Your not understanding the principal of this. I wish I could show you hands on what would happen. I have seen this with diasterous problems.

I'm saying this cause you said in the quote "year-round air conditioning". Just letting ya know,what I know! :thumbsup: Just trying to be of some help to you as well as others..

Peace! My Brutha!:smokin:

keylime
01-16-2011, 07:57 PM
That would be why you have an exhaust fan and a passive intake vent with a damper. Your not understanding the principal of this. I wish I could show you hands on what would happen. I have seen this with diasterous problems.
I'm saying this cause you said in the quote "year-round air conditioning". Just letting ya know,what I know! :thumbsup: Just trying to be of some help to you as well as others..
Peace! My Brutha!:smokin:

I"m not trying to rub anyone in the wrong way. A sealed room means exactly that. There are no vents ...intake or exhaust. So all you have the the air inside that room (more or less... There is always some heatloss and heatgain) and you want to keep a certain temperature and humidity. The CO2 could come on only if the conditions are perfect.... that is temp is between 73 and 79, humidity is below whatever the dehumidifier is set at. If its too hot in the room, say its 80F, the A/C goes on, and lets say it goes off at 72F. The dehumidifier can run right alongside the A/C and get the humidity out even if the temp is below 72F. IF its above 72F and the humidity is high, then both will run until one shuts off. I suppose there are many ways to skin a cat, but I know for a fact that this will work for a sealed room.

keylime

GaGrown
01-16-2011, 10:27 PM
I"m not trying to rub anyone in the wrong way. A sealed room means exactly that. There are no vents ...intake or exhaust. So all you have the the air inside that room (more or less... There is always some heatloss and heatgain) and you want to keep a certain temperature and humidity. The CO2 could come on only if the conditions are perfect.... that is temp is between 73 and 79, humidity is below whatever the dehumidifier is set at. If its too hot in the room, say its 80F, the A/C goes on, and lets say it goes off at 72F. The dehumidifier can run right alongside the A/C and get the humidity out even if the temp is below 72F. IF its above 72F and the humidity is high, then both will run until one shuts off. I suppose there are many ways to skin a cat, but I know for a fact that this will work for a sealed room.

keylime

kelime,
You ain't rubbin' me no kinda way! This is a discussion amongst adults..

That would work for a sealed room! But alot is overkill.. With the damper being on the intake you won't compromise anything. Air scrubber on when co2 ain't.Damper opens and freshens the air, lowers the temps and humidity.You have to take into consideration that the hood being used is a sealed one. You then cool your lamp for the whole time the lights are on.You add 300 ppm of co2 by using a passive intake,not your co2 supply.scrubber goes off and co2 emits.A humidistat can be used inline on the scrubber,too.. That would make the scrubber come on when the humidity raises.Set it to what ever ya want.Tryin' to keep it all simple.:thumbsup:

Peace! My Brutha!