Ideas needed for cooling grow room. Pics of setup

Hi all,
Got a question about cooling a grow room. I am certain that between the temps and the humidity that I am getting, my plants are suffering. I need any ideas on how to get the temps into a range that I can use and get the humidity up at the same time. I am hoping to find an inexpensive way of making this happen!
The room is a bathroom off of the master bedroom. Because of the fact that I have the lights on a 20/4 schedule right now, I sometimes have to close the door to the room at night so we don't have several hundred watts of light on while we try to sleep. When I have the door open, with a large fan blowing in cool air, I can maintain about 82 degrees with 35-40% RH. With the door closed, however, the temps jump up to around 90 and the humidity falls a bit. The plants are about to go on to 12/12 but I want the environment to be right for a good harvest. I need any advice about how to get the temps and humidity into the range that it needs to be, please help a beginner out!




This is the fan blowing cooler air into the room. I don't know the CFM, but I can say that it is pushing a lot of air into such a small room.



This is an overview of the actual grow area. The big fan is just out of frame to the left of the pic here.



A little closer in the grow area. Note the fan in the back of the shower enclosure blowing air across the plants and out of the enclosed area. The rags are wet and put in to try and help raise the humidity some in the enclosed area. Also, the door to the shower enclosure is never closed, I think that would make it well over 100 degrees inside....



And finally, a shot of one of my girls... BS 2 (Bag Seed #2) and the temp / RH gauge that I am using.

Again, ANY help or ideas to get these parameters into the best grow zone is greatly appreciated!

Allister said:

Hi all,
Got a question about cooling a grow room. I am certain that between the temps and the humidity that I am getting, my plants are suffering. I need any ideas on how to get the temps into a range that I can use and get the humidity up at the same time. I am hoping to find an inexpensive way of making this happen!
The room is a bathroom off of the master bedroom. Because of the fact that I have the lights on a 20/4 schedule right now, I sometimes have to close the door to the room at night so we don't have several hundred watts of light on while we try to sleep. When I have the door open, with a large fan blowing in cool air, I can maintain about 82 degrees with 35-40% RH. With the door closed, however, the temps jump up to around 90 and the humidity falls a bit. The plants are about to go on to 12/12 but I want the environment to be right for a good harvest. I need any advice about how to get the temps and humidity into the range that it needs to be, please help a beginner out!


View attachment 1433893

This is the fan blowing cooler air into the room. I don't know the CFM, but I can say that it is pushing a lot of air into such a small room.

View attachment 1433894

This is an overview of the actual grow area. The big fan is just out of frame to the left of the pic here.

View attachment 1433895

A little closer in the grow area. Note the fan in the back of the shower enclosure blowing air across the plants and out of the enclosed area. The rags are wet and put in to try and help raise the humidity some in the enclosed area. Also, the door to the shower enclosure is never closed, I think that would make it well over 100 degrees inside....

View attachment 1433897

And finally, a shot of one of my girls... BS 2 (Bag Seed #2) and the temp / RH gauge that I am using.

Again, ANY help or ideas to get these parameters into the best grow zone is greatly appreciated!

Click to expand...

Do you have a the bathroom exhaust fan running all the time?? Does your bathroom even have an exhaust fan???

The only way to cool that room without getting an AC is to aircool the lights and vent that air outside.....If your in a bathroom then you should have easy access to the exhaust vent.......Take the bathroom exhaust fan out then hook up a real inline fan to that exhaust hole and then vent out your room directly out the bathroom exhaust fan.....You might wanna consider getting real lights down the future too....With out proper ventalation you will never have good temps........

Oh and a fan blowing at the door is NOT proper ventalation just to let ya know...

Hey man, I think Foot clan has got a point about the Ventillation. I am pretty new to but what i would say id from your pics your plants leaves are looking pretty droopy, which means they are not liking something. As for getting the humidity up, a cheap method i use in my own grow room is getting a tray, or bucket ( somethnig to catch water) wetting a towel and letting it drip, and evapourate water for several hours untill its dry. if yours is in a shower tray you may not even need a bucket, just wet one or two towels, hook them through a hanger and hook them over the side of your shower glass or something.This should relly help the humidity.

As For the high temps, crack a window? is there one>? do you have an exhaust fan for the bathroom? whats above you? is it attic?

Laugh.. The bounce sheets on the back of a fan.. I have used that SOO many times. It's SOo gettho but it really does work to a certain extent!

Charcoal filter mate.. Actaully Im working on something myself. I have a 6" inline fan found in the venting section of your local big box store. Cost me abuot $70 for a 200 CFM one. Mount that in the room going outside. Then I added a 6" 90degree elbo & a abuot a 12" piece of 6" pipe. In the 6" pipe I wrapped that in my wifes nylons & filed it with activated charcoal frmo the pet store. It draws all the air out of my box over the charcoal which is a 12" thick layer wrapped in nylons to prevent it from being pulled out.

My plants are only sprouts at this point so I can;t vouch for SURE that this works but I have a very good feeling abuot it.... I grow in a cabinet & vent it directly into my finished basement so smells & cool is an issue for me.

Good luck & search around on here. You will find MULTIPLE fixes for your problem.

Good luck/

FootClan said:

Do you have a the bathroom exhaust fan running all the time?? Does your bathroom even have an exhaust fan???

The only way to cool that room without getting an AC is to aircool the lights and vent that air outside.....If your in a bathroom then you should have easy access to the exhaust vent.......Take the bathroom exhaust fan out then hook up a real inline fan to that exhaust hole and then vent out your room directly out the bathroom exhaust fan.....You might wanna consider getting real lights down the future too....With out proper ventalation you will never have good temps........

Oh and a fan blowing at the door is NOT proper ventalation just to let ya know...

Click to expand...

I actually have been thinking about that. I would have to put a filter on it before I vent it out as we are in a condo with another unit directly above.
I do have an exhaust fan and it has been running non stop for about a month now. It helps a tiny bit but doesn't draw anywhere near enough air to lower the temps by 5-8 degrees alone.
And while I realize that a fan in the door and another in the grow area is not really the best in circulation, it is the best that I have at the moment. I have to admit that I thought between the two fans and all of the air that it is moving, it would have been sufficient for keeping the temps down for a cfl grow...

carl.burnette said:

Laugh.. The bounce sheets on the back of a fan.. I have used that SOO many times. It's SOo gettho but it really does work to a certain extent!

Charcoal filter mate.. Actaully Im working on something myself. I have a 6" inline fan found in the venting section of your local big box store. Cost me abuot $70 for a 20 CFM one. Mount that in the room going outside. Then I added a 6" 90degree elbo & a abuot a 12" piece of 6" pipe. In the 6" pipe I wrapped that in my wifes nylons & filed it with activated charcoal frmo the pet store. It draws all the air out of my box over the charcoal which is a 12" thick layer wrapped in nylons to prevent it from being pulled out.

My plants are only sprouts at this point so I can;t vouch for SURE that this works but I have a very good feeling abuot it.... I grow in a cabinet & vent it directly into my finished basement so smells & cool is an issue for me.

Good luck & search around on here. You will find MULTIPLE fixes for your problem.

Good luck/

Click to expand...

I have actually been doing the research on a DIY filter these last few days... But until I get time off and get it built, I thought I would use the old college days cure and do the bounce! Gotta admit that I am kinda tickled that someone noticed! LOL

What is the ambient temperature of your place? Without AC your grow area will always be ~10 degrees warmer than ambient temp due to the immediate albedo of everything within the lights reach. Other than covering everything in reflective material there is nothing you can do about that. If your appartment/house is around 76 degrees don't worry about it. I had a closet grow in the middle of summer with the temp averaging over 100 and the bud came out great:




Adding simple C02 supplementation is another easy fix for high temps. Doesn't lower the temperature but allows the plants metabolic functions to run more quickly (a function of higher temps) while maintaining homeostasis.

Yeah, we keep it around 70 in here so I anticipated it being a little warmer. I was just worried about stunting the plants growth.. I know that around here in the summer there is weed grown outdoors in hundred degree weather, I was just wanting to make sure that I am giving these girls every chance to be and stay female. Thanks again for the calming words! Adding CO2 is a little more advanced than I am at this point. Plus, with having to keep the door to the room open to even maintain the temps that I have, I think it would be a waste to try to add it.

You're ask for trouble running your bathroom vent with out a filter, best bet is to run a vortex like fan with a carbon scrubber and route it through the exhaust fan vent, Make sure you know where it's venting to, as it could call attention.

Believe me, I know. That is why it is next on the list. Didn't really expect to need it this soon with bagseed. That is also why at least for the moment I am going with the low tech approach and I have the bounce on the back of the fan covering all of the aroma prior to the exhaust fan taking it out.
For just bagseed, I have to say that I am impressed with the smell at least of these plants. But still looking for ways to get the temps where I would like for them to be in the grow area...

It looks to me like you have the plants in the shower stall yes? I think you could probably have better air circulation without wind burning the plants. A couple of things come to mind; if you create a mesh type table/shelfs so the plants were off the floor and have your fan underneath it blowing up (but not directly on a plant). And take the reflectors off the cfl's so you can get them closer in between the plants but also have enough free space for air movement. I'd utilize the bath vent but not the fan. It's loud and can't be tuned to a whisper. Unfortunately, it's probably a 4" vent. If there is a window close I would route my intake and output vents to that. Maybe use the casing of a non-working AC unit so it's stealth from the outside.

what about going to a 18/6 light schedule.. it would be a little cheaper too.. or y not change the light schedule so that the 4hr dark period would corrispond with when u lay down so u get a few hrs to get deep into your sleep before the light comes on. or better yet ( if u prefer a quick/ ghetto solution) go to a home depot, lowes , or wat ever u all have. and buy some plastic sheeting (its like a long as roll of garbage bags not cut into garbage bags) and some dryer hose. sit the hose on the floor and hang the plastic over the door way (duck tape works just fine) if need be i would sit a small fan inside by the hose. but the plastic sheeting... the BLACK plastic sheeting will block all the lightView attachment 1435043View attachment 1435044 it worked for me

Which brings another question to mind to put out there... Would removing the reflectors on these lights bring down the temps? By removing them, would it be degrading the amount of light that I can direct to the plant?

meetjoeblow said:

what about going to a 18/6 light schedule.. it would be a little cheaper too.. or y not change the light schedule so that the 4hr dark period would corrispond with when u lay down so u get a few hrs to get deep into your sleep before the light comes on. or better yet ( if u prefer a quick/ ghetto solution) go to a home depot, lowes , or wat ever u all have. and buy some plastic sheeting (its like a long as roll of garbage bags not cut into garbage bags) and some dryer hose. sit the hose on the floor and hang the plastic over the door way (duck tape works just fine) if need be i would sit a small fan inside by the hose. but the plastic sheeting... the BLACK plastic sheeting will block all the lightView attachment 1435043View attachment 1435044 it worked for me

Click to expand...

I have actually been thinking of something like that. I was going to get a black curtain or something to hang over the door, so that I could leave it open and then run a fan in some ducting so that some cool air could still be getting pulled in there without the blasting light. I might give that a shot in conjunction with the carbon filter that I am looking to build. Just leave it running all night and when needed to scrub the air.

carl.burnette said:

Laugh.. The bounce sheets on the back of a fan.. I have used that SOO many times. It's SOo gettho but it really does work to a certain extent!

Charcoal filter mate.. Actaully Im working on something myself. I have a 6" inline fan found in the venting section of your local big box store. Cost me abuot $70 for a 20 CFM one. Mount that in the room going outside. Then I added a 6" 90degree elbo & a abuot a 12" piece of 6" pipe. In the 6" pipe I wrapped that in my wifes nylons & filed it with activated charcoal frmo the pet store. It draws all the air out of my box over the charcoal which is a 12" thick layer wrapped in nylons to prevent it from being pulled out.

My plants are only sprouts at this point so I can;t vouch for SURE that this works but I have a very good feeling abuot it.... I grow in a cabinet & vent it directly into my finished basement so smells & cool is an issue for me.

Good luck & search around on here. You will find MULTIPLE fixes for your problem.

Good luck/

Click to expand...

That might work if he was worried about smell but hes worryed about the heat so ya the carbon filter has nothing to do with heat......

true, but it was still the NEXT problem on the list to check off... so if I can kill two birds with one stone, that would be good too. I am thinking of even getting a really small ac unit like a small window type to put in there. Was thinking I would just put it on the sink in there. That would raise RH, and cool it a bit... I am just trying to save on elec. which is one of the reasons I went with a cfl garden.

Allister said:

Which brings another question to mind to put out there... Would removing the reflectors on these lights bring down the temps? By removing them, would it be degrading the amount of light that I can direct to the plant?

Click to expand...

Yes it would help a little bit with temps but you will loose all your reflection so it dosent really help becasue anything you gain will be lost in lack of light so you will still yield the same really....Also you say you cant exhaust out your bath room vent because your neighbors?? That dosent make sense you bathroom vent isnt connected to your upstairs neighbor ............The vent from a bathroom must exhaust out the roof that means if your in an apartment and you are down stairs the air that your little bathroom fan sucks up gos straright out the the roof theres no way anyone would smell it...How would they smell it?? Its not like the vent leads up into the upstairs apartment or somthing.....If it did that would mean everytime you take a shower there apartment would get blasted with wet humid air from your bathroom .........So you should do what i said take the bathroom fan out of the ceilling then hook an inline fan and some ducting to the vent hole and just use the vent ducking that came with the apartment for your bathroom and just tie into that ..........this is simple and the only thing you can do to solve the problem.......Theres no need to debate here or over think it.....Its very simple you must take your hot old air in your bathroom and move it someplace else outside your apartment.....Which means you gotta get it outside.....Now if your bathroom fan is already running 24/7 like you said then you are already doing what im suggesting the difference is you need a bigger fan and you need to run ducting from the fan right up to your light bulbs so its sucking the heat from the source.....Right now your just sucking in the hot air after it as moved to the ceiling.....You need to extend the reach of the fan by connecting ducting and placing it where the heat is most.....Even after doing this if you dont have a proper hood its still going to be a challange.......U can spend hours and hours trying to figure out a way to lower temps by placing a fan under this or over that and bla bla bla the fact remains that you gotta get a bigger exhaust fan and you gotta redirct it outside......Wether that means using your bathroom fan like i suggested or running it out through a spare bedroom window its gotta be done Period......

Dont think that having 100 degree temps is just fine like that guy stated above thats bullshit bro......If your temps hit a 100 in your bathroom you can beleive all growth as pretty much been stopped or stunted during that period......Just becuase someone says ya its ok my plants came out good.....well maybe his good is different then your good its a reletive term man and any temps over 85 is asking for trouble and is diffenelty not going to yield up to its max potenial......

Also the Co2 thing ya it allows you to have higher temps but You dont even a exhaust system or dedicated fan for lights or even a hood or pretty much anyting you would need to have a proper grow so how in the heck would anyone think you could add Co2?? you couldnt and it would be a hudge waste of time and money....Get the bare bone basics down then move to more advanced things like Co2

Allister said:

true, but it was still the NEXT problem on the list to check off... so if I can kill two birds with one stone, that would be good too. I am thinking of even getting a really small ac unit like a small window type to put in there. Was thinking I would just put it on the sink in there. That would raise RH, and cool it a bit... I am just trying to save on elec. which is one of the reasons I went with a cfl garden.

Click to expand...

I see that and most want to save money but the money saved just equals out to less yield and if you had a real light you would spend more in power but yu would yield alot more in the end so it stills even out really. you want to save money and grow less which means you spend less in the long run or do you want to spend more and yield more and if you yeild more well then you make up the difference in the extra Pg&e........also beware of those DIY filters ya you can make one but will it work that good?? chances are it wont work as good as if you bought a nice one and i know it will work better then some carbin in a panty hose....

Footclan is right.

You must vent your old air OUTSIDE and suck in fresh air (from your apartment will do). You need this constant air exchange so the plants are getting plenty of natural co2, and bring the temperatures down... Its no good just blowing hot, stale air around a little room. Get a decent exaust fan, connect it to where your crappy little bathroom exaust fan is now, via a carbon filter.

If you had a HID light, more of the electricity it chews would convert to more plant growth, while the cfls are less efficient for plants. You have to have them really close too

I see I made a mistake. its a 200 cfm fan. Not 20 cfm.

Sorry.