Fans??

How often should i vent the dead air out of my growroom?? The room is 800 cubic feet. Should i have a bigger fan than 150cfm?? Thanks for all your post.

what is this, like a bedroom? The most important info that you left out is the piece of equipment that is producing the heat....your light, what do you got for lighting?

creative_mind said:

How often should i vent the dead air out of my growroom?? The room is 800 cubic feet. Should i have a bigger fan than 150cfm?? Thanks for all your post.

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I agree. You must take heat into consideration when venting. How hot does your light get? Are you using an air-cooled hood?

How big is the air intake in your room and where is it?

i have 2 hps 1000 w lights and 6 4' floro tubes

i have an intake 1' from the floor and an exhaust in the ceiling. i dont kno how big of a fan to use for my lights and space tho.

Each fan has a rating that tells you how many cubic feet of air per minute (CFM) it will move. When dealing with above average temperatures you will want your fan to exchange the grow room air 3-5 times in one minute, so for a room that is 40 cubic feet, a fan that is capable of moving 120-200 cfm (cubic feet per minute) is recommended. If you only want to replace depleted levels of co2 and are growing in a closet using fluorescents, one room change per five minutes (divide room size by 5) will be adequate.

Damn, with 2 1k watters, you should be air-cooling them unless you live in a cold climate. I would also recommend bumping the fan up to at least an 8" can fan or the equivalent.

A 90 CFM with a 600 watt light will raise your temperature above the intake by 21°. The 240 CFM fan will raise it 8°. 90 CFM wouldn’t be enough. It’s not the size of the cabinet that you want to take into consideration; it’s the wattage being used.

(600 × 3.2) ÷ 90 = 21.33

(600 × 3.2) ÷ 240 = 8

To find how much the light will warm the room with a different size fan you can just use the formula. Just take the wattage of the light and multiply by 3.2. Then divide the CFM of the fan to find how much the room will warm in Fahrenheit degrees.

For instance:

If the temperature of the intake air is 75° and you’re using a 600 watt light, the temperature would go up 5° if you used a 384 CFM fan. So, the temperature would end up 80°.

(600 × 3.2) ÷ 384 = 5

5° + 75° = 80°


your setup:
2000watt lights x3.2=6400
6400 ÷ 900=7.11


If yr using 2 1000 watt lights, have you considered co2? If not a 900 cfm setup will raise your temps by 7 degrees.
Peace

creative_mind said:

i have 2 hps 1000 w lights and 6 4' floro tubes

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thanks video for all ur help that equation u posted is awsome, always tryin to learn new things about growing.... thanks everyone for all ur posts