Ventilation question

Hi
I wonder if anyone can advise me (again!) there's one thing that troubles me about ventilation.

If I am to keep my grow room at around 78 degrees and I am intaking air from outside to cool the room, what happens when it's more than 78 degrees outside? Surely if the outside air is warmer than the temperature I desire then it wont cool it down?

Would I be better off taking air from a room inside, although what concerns me about this is this air will be much more humid.

Any thoughts gratefully welcome

If this is a problem that will occur quite often where you live i would look at investing in a small shitty portable a/c. I use one over summer and its perfect for keeping the temp down. Other options are like you said pulling air from another room or even from under the house if possible.

get a dehumidifier then to make the room less humid or buy a fan with a cooler built in.

Will a dehumidifier help lower the temp then?

I have one of those already so thats not a problem to use

Thanks

Hey GreenGro,
I dont know where you live, but it is usually more humid outside than inside, no? Anyway, if need be, get a dehumidifier, although this will not change the temp, it'll solve one of your problems.
Peace

GreenGro said:

Hi
I wonder if anyone can advise me (again!) there's one thing that troubles me about ventilation.

If I am to keep my grow room at around 78 degrees and I am intaking air from outside to cool the room, what happens when it's more than 78 degrees outside? Surely if the outside air is warmer than the temperature I desire then it wont cool it down?

Would I be better off taking air from a room inside, although what concerns me about this is this air will be much more humid.

Any thoughts gratefully welcome

Click to expand...

The single most important thing you can do is put an exhaust fan in the light hood.

I have seen the post several times and it was the last thing I did and the only thing that worked to get my temp down.

hear is what I did
grow room size 3' x 4' x 7'
400 w MH bulb
exhaust the grow room 6" 294cfm fan through 4" duct to outside ( couldn't get 6" )
exhaust the light hood 3" computer case fan
feed fresh air from ajoining room 6" 294 cfm fan

abient room temp 72 deg f
grow room temp 78 deg f

If I had one of those heat buster hoods both temps would be the same or 1 deg differance

I had all my fans in place except the light hood one and my grow room temp was 90 - 95 deg f all the time. I gave up and was taking down my grow room then some one post exhaust the light hood. 3" computer fan problem fixed

This is my strategy (i have a similar situation to yours).

Just run your light cycle at night, starting at 7pm. In the beggining, you have the lights on until between 11am and 1pm depending on your veg cycle (16-18 hours). Then once you go into budding, the cycle ends at 7am (12/12).

This way, you are not using lots of power during peek hours (daytime), and during the day when the outside air is warm, you don't have the hot lights on also. Then at night when your lights are generating lots of heat, you have cool air coming in from outside to cool the area down (an oscillating fan is a must, imho).

I'm not that experienced, but it's working well for me. My room temp is 74f and humidity 50% at night with the lights on. During the day, my room temp is 71f with 60% humidity.

Edit: When the hot summer months roll around, i may still need to get a small a/c for really hot days but so far, so good.

videoman40 said:

Hey GreenGro,
I dont know where you live, but it is usually more humid outside than inside, no? Anyway, if need be, get a dehumidifier, although this will not change the temp, it'll solve one of your problems.
Peace

Click to expand...

I don't know for sure but I just assumed that the relative humidity would be higher inside what with baths, showers, washing things etc. than it would be outside.