Help with heat problem - pics

The grow space is a little storage area in my garage under stairs. I can't really ventilate anywhere but out into the garage (surronded by stairs and living space).

There is enough room to turn that metal shelf 90 degrees and fit an a/c unit or evaporative cooling in the back left corner of the space.

I had an idea to seal the space off, run ventilation, and also add cooing inside and I wondered what the best way to do this would be.

My plan is to first frame out the 5' x 3' "doorway" and within the door frame to have two corners frames for a mounted duct intake and exhaust. I'd order the 4" ducting exhaust attachment for the 150 watt hps light and run from the light to the fan to the exhaust mount to more ducting to a carbon filter outside the area.

I would use ducting to run the intake from the door to the back corner of the room near the a/c intake. And as for that cooling; I'm leaning more toward evaporative because my humidity is low and will get lower in the next few months as temps increase. Because I use a stronger fan for the carbon filter, I would leave the intake passive.

Finally, I would use black and white poly to seal the remainng open part of the frame and make the door. It would be secured on one side and tear away with velcro around the rest of the frame. I would also use silicon or something to seal the frame seams.

Please let me know what you think. Is the black and white poly the right material to use? Is this whole thing crazy, lol? It's going to get real hot here pretty soon. but I should be able to control this small space especially since I am willing to spend on cooling.

I'll even take someone's guess on how this will work. I'm about to spend a fair amount of money on ventilation and cooling and I would really appreciate some feedback from one of you who knows a little about this stuff.

Please take a look at my journal too. People are viewing, but I'm not getting any replies. Feel like the nerdy kid on the RIU playground.

Be brutally honest. If it won't work tell me it won't. I even considered ordering an actual hinged door and frame custom for that opening.

I just want to get it right. I would be greatful for a couple of opinions.

Thank you.

XXO, there is no right or wrong way to do things. Some work better than others but nobody is going to say 100%.

It sounds like you are going to vent the hot air from the A/C exhaust through the door. I would say to make sure the fresh air intake is not next to the exhaust or you will be recycling the air.

There are alot of factors such as ambient temperature of the garage, relative humidity and the effect of the house interior temperature and insulation in regards to that wall.

As long as you have fresh air that you can condition to below 90 degrees and preferrably low 70's with RH between 70 - 50% then your ventilation problems are solved.

Yeah man it looks pretty good and sounds like you have a plan! But, like NLK said the hot air exhaust should be higher than the intake (duh) seeing how hot air rises and all oh btw what are the small lights for?

I have run into the same problem in a basement. Very hot in the summer and the heat skyrockets (destroyed my last grow) and in the winter the temperature plummets. I had to cut into my box (luckily i had made it out of drywall so this was very easy) and shove an AC unit in there. I have to build a box around the ass-end of the AC unit and put a scrubber on that now to make sure no smell escapes.

Your plan sounds like it will work. The panda plastic should work nicely as it is designed for this type of use. Though you'll have to watch how you seal it since some of those caulks remain moist - and others harden and crumble. Tape may be better - but your mileage may vary.

you are right on the money regarding humidity - the AC will suck the humidity right out.

So your temp-control plan sounds like a good one (do you also have to worry about cold temperatures)?

If you are growing hydro, hopefully the ac will keep the reservoir temps down enough so you don't have to invest in a chiller -- those things can be pricey!

The only other comment i have is to mention that you aren't giving yourself very much vertical space to grow in ... are you using CFLs? If you are using HIDs, you won't be able to let your plants get very big.

NLX, Dr., and email;
thanks for the feedback. It is much appreciated. I will definitely have the intake at the bottom and the exhaust up top. Also, great heads up about the caulk either crumbling or staying wet. I'll just use more glorious duct tape.

It will take me a little bit to get everything ordered and build it, but I will put up pictures when I'm done. Thanks again guys.