Ideas on how to lower grow room temps. HELP PLEASE

[O.CBBS]

HELP I have a 4x2 tent with a 315w cmh light 4” exhaust fan (195 cfm) and fans blowing a lot air around in the tent. With lights on tempt are up twards 87 lights off is not a problem being down to 72. The temp in the house is kept at 75. Please help I’ve run outa ideas

 

[Gashuffer]

I'd move your exhaust fan to be above your light. It'll be hotter up there as that light is easily the largest heat generator in your tent.

What other things have you tried?

Do you have enough air coming into the space? (Do the sides suck in when you've got the exhaust fan on?)
Is the exhaust fan on the highest setting? (seems like a silly thing to ask)

 

[Aqua Man]

First where is your thermometer?

 

[O.CBBS]

I'd move your exhaust fan to be above your light. It'll be hotter up there as that light is easily the largest heat generator in your tent.

What other things have you tried?

Do you have enough air coming into the space? (Do the sides suck in when you've got the exhaust fan on?)
Is the exhaust fan on the highest setting? (seems like a silly thing to ask)

I’ll try that out! It’s just felt hotter right where I put it so I was trying to suck that hot air directly out.
I don’t know what else to try, I’ve tried playing with the positive and negative air pressure, different fan set ups, even different rh.

 

[O.CBBS]

First where is your thermometer?

I have it hanging at canopy level almost directly in the center

 

[Aqua Man]

I have it hanging at canopy level almost directly in the center

There is your problem. Move it to canopy level in the shade. A couple inches from the wall is fine. Tape something to the wall to shade it if you have to. Then let us know the temperature.

 

[Aqua Man]

Then the next thing is to buy an IR temp gun and check the canopy leaf temps. This is the actual important part. Leaf temp are not the same as air temps. Without CO2 if you go over 80f leaf temps you may start seeing issues. Different strains will have different tolerance. So not a bad idea to do a bit of research on the strain before ya grow. If you have higher temps pic something that is well suited for it.

 

[O.CBBS]

I'd move your exhaust fan to be above your light. It'll be hotter up there as that light is easily the largest heat generator in your tent.

What other things have you tried?

Do you have enough air coming into the space? (Do the sides suck in when you've got the exhaust fan on?)
Is the exhaust fan on the highest setting? (seems like a silly thing to ask)

I’ll try that out! It’s just felt hotter right where I put it so I was trying to suck that hot air directly out.
I don’t know what else to try, I’ve tried playing with the positive and negative air pressure, different fan set ups,

Then the next thing is to buy an IR temp gun and check the canopy leaf temps. This is the actual important part. Leaf temp are not the same as air temps. Without CO2 if you go over 80f leaf temps you may start seeing issues. Different strains will have different tolerance. So not a bad idea to do a bit of research on the strain before ya grow. If you have higher temps pic something that is well suited for it.

ok will do! Thank you for the info! Ima go get one and see where I’m at. If they are over 80f would something like an exhale bag work for co2 in my setup?

 

[Aqua Man]

I’ll try that out! It’s just felt hotter right where I put it so I was trying to suck that hot air directly out.
I don’t know what else to try, I’ve tried playing with the positive and negative air pressure, different fan set ups,

ok will do! Thank you for the info! Ima go get one and see where I’m at. If they are over 80f would something like an exhale bag work for co2 in my setup?

Nope... But improving airflow and exchange can. You can increase the cooling ability of a leaf by ensuring good VPD which will increase transpiration rates, forced evaporation by increasing airflow through the canopy (not too much or you will windburn them)

Then you can increase air exchange to bring in more cooler air, use added ventilation on the light.

Best thing is to first get accurate air and leaf temps because you may need to do none of those

 

[O.CBBS]

Nope... But improving airflow and exchange can. You can increase the cooling ability of a leaf by ensuring good VPD which will increase transpiration rates, forced evaporation by increasing airflow through the canopy (not too much or you will windburn them)

Then you can increase air exchange to bring in more cooler air, use added ventilation on the light.

Best thing is to first get accurate air and leaf temps because you may need to do none of those

Ok the light just turned on

Nope... But improving airflow and exchange can. You can increase the cooling ability of a leaf by ensuring good VPD which will increase transpiration rates, forced evaporation by increasing airflow through the canopy (not too much or you will windburn them)

Then you can increase air exchange to bring in more cooler air, use added ventilation on the light.

Best thing is to first get accurate air and leaf temps because you may need to do none of those

ok ima give it a day and get exact readings and go from there then! I’ve moved the fan up and moved the hygrometer. Thank you for the advice!

 

[Aqua Man]

Ok the light just turned on

ok ima give it a day and get exact readings and go from there then! I’ve moved the fan up and moved the hygrometer. Thank you for the advice!

Don't need a day. Just got in there after a few hrs and it should be up to Temp

 

[O.CBBS]

Don't need a day. Just got in there after a few hrs and it should be up to Temp

This is all three taken on the top leaves. Guess I don’t need to adjust?

 

[Aqua Man]

This is all three taken on the top leaves. Guess I don’t need to adjust?

75-77f leaf temps ideal for photosynthesis without CO2...

Your golden bro

 

[O.CBBS]

75-77f leaf temps ideal for photosynthesis without CO2...

Your golden bro

Thank you for the help and advice bro!

also check out my Instagram if you want. I’m new to growing so I’m kidding just putting pics out there for fun. Just where I document my grow! @Octoberscollective

 

[One drop]

Passive air intake would help as well .OD .

 

[Aqua Man]

Thank you for the help and advice bro!

also check out my Instagram if you want. I’m new to growing so I’m kidding just putting pics out there for fun. Just where I document my grow! @Octoberscollective

I would if I had instagram but I don't. To old... Lol

 

[O.CBBS]

Passive air intake would help as well .OD .

Do you mean like no negative or positive pressure on the tent?

 

[One drop]

Do you mean like no negative or positive pressure on the tent?

I use a old cleaned nut bottle round one at that cut top n bottom off put black stocking or fine material cover both ends open up the bottom round hole at bottom of tent stick the tube in tighten up the ties around the tube have your exhaust fan running 24/7 do up the tent the exhaust fan sucks fresh cool air in through the tube you made to fit through the tent hole passive air is no archived . Regards OD .

 

[Aqua Man]

I use a old cleaned nut bottle round one at that cut top n bottom off put black stocking or fine material cover both ends open up the bottom round hole at bottom of tent stick the tube in tighten up the ties around the tube have your exhaust fan running 24/7 do up the tent the exhaust fan sucks fresh cool air in through the tube you made to fit through the tent hole passive air is no archived . Regards OD .

Love that little grow hack.

 

[One drop]

Love that little grow hack.

It one of the simplest and easy way to do it , I’m always looking for as my wife calls it Farm Fix . What can I say I’m a cheap ass Irishman .....