Cold Air Ventilation

[keeger123]

If I use a CO2 unit I don't have to exhaust the room air at all, right?.....Depending on the humidity in the room when it is up and running, you may have to exhaust.

if u dont exhaust, ur room will be so humid and musky that it'll be hard to breathe in there, depending on how big ur grow is... exhaust is a must

 

[stumps]

So you don't think a 1000w will cover a 4x5 area? That sounds reasonable and about right to me, but I have zero experience and am only going by what I have read.

I will be using one 440CFM fan for both lights. Would you consider that to be "very strong"?

As for the outside room staying 40... That is without pulling cold air into it. If it is 10 degrees outside and I have a 440CFM pulling that air in, then it won't be 40 in there for long. Still though, I guess it is best to pull into the garage 1st and then into the grow room... That seems to be the consensus/smart thing to do.

As for a CO2 set up. What would you suggest for that and how much would it end up costing (rough estimate)? I guess I would be able to save a little by not having to set up an exhaust system to help offset whatever the CO2 would cost me.

I was saying a little light with a 4x5 area a 1000w will do 6x6 easy. If you pull the air from outside to your lights then to the outside room you would heat the air before it gets to the inside room keeping it warmer and still get fresh air in. then you could vent from the out side room into the grow room and then back outside.

 

[ForbiddenFruit]

if u dont exhaust, ur room will be so humid and musky that it'll be hard to breathe in there, depending on how big ur grow is... exhaust is a must

OK.. So I think I will do this then:

I will pull air in from outside and have it run through my lights and then send it right on back outside. Have the room sealed and release CO2 whenever the lights are on.

Then, when lights are off I will set it up so that the room is ventilated. Maybe even using a "Y" attachment at the end of the tubing (just past the lights) and setting it so that one fan runs when the lights (and CO2) are on (sending the air out of the room)

AND

setting the other one to pull it into the room when the lights are off (running simultaneously with the exhaust fan). So that fresh air is pulled in and circulated during that dark time.

Make any sense?

 

[ForbiddenFruit]

I was saying a little light with a 4x5 area a 1000w will do 6x6 easy. If you pull the air from outside to your lights then to the outside room you would heat the air before it gets to the inside room keeping it warmer and still get fresh air in. then you could vent from the out side room into the grow room and then back outside.

Understood. Makes sense.

Still, my main concern is the bulbs potentially bursting when that cold air hits them. Obviously it wouldnt suddenly be subfreezing air hitting an already hot lamp (sure to cause problems), since the fan will come on right away when the lights are initially turned on (and not yet hot), but it would still be subfreezing air nonetheless. Which worries me a bit.

 

[stumps]

I've had my 400w with air in the mid teens. But my outer room is much warmer.

 

[stumps]

I've been searching for hps light temp stuff. Didn't find what I wanted. This my sound smart ass but look outside do you have any street lights near by? if so their most likley hps. The hps burns at about 600 deg. I just don't see cold air cooling that enough to hurt the bulb. Just my thoughts can't find much to back it.

 

[mrmadcow]

stumps is right, HPS lights are used all the time outside

 

[ForbiddenFruit]

I've been searching for hps light temp stuff. Didn't find what I wanted. This my sound smart ass but look outside do you have any street lights near by? if so their most likley hps. The hps burns at about 600 deg. I just don't see cold air cooling that enough to hurt the bulb. Just my thoughts can't find much to back it.

No sir... You dont sound like a smart ass at all. Makes sense.

Thanks for ALL of your input.. I appreciate your taking the time to respond.

cheers

btw.. on a side note.. no street lights where i am at. out in the middle of nowhere. just a couple of neighbors.

 

[keeger123]

OK.. So I think I will do this then:

I will pull air in from outside and have it run through my lights and then send it right on back outside. Have the room sealed and release CO2 whenever the lights are on.

Then, when lights are off I will set it up so that the room is ventilated. Maybe even using a "Y" attachment at the end of the tubing (just past the lights) and setting it so that one fan runs when the lights (and CO2) are on (sending the air out of the room)

AND

setting the other one to pull it into the room when the lights are off (running simultaneously with the exhaust fan). So that fresh air is pulled in and circulated during that dark time.

Make any sense?

with 20 plants in the room, it will get really musky within 30 min. i thought the same thing, that u wouldnt have to vent all that much...

this is what ppl do with co2... while the lights are on, they will inject co2 up to 1500ppm for at most 20 min while the exhaust's off, any more co2 is a waste. then the stop injecting and turn the exhaust on. they let exhaust run for 1 or more hours, then repeat the cycle. no co2 during night. the co2 isnt suppost to be injected all day, and the room must be exhausted while lights are on and off. to much co2 will burn plants. not enough ventilation is unhealthy for plants, they would be better off with no co2 and full exhaust in my opinion, that is till u figure out a co2/exhaust schedual or get an environmental controller

 

[keeger123]

I was saying a little light with a 4x5 area a 1000w will do 6x6 easy. If you pull the air from outside to your lights then to the outside room you would heat the air before it gets to the inside room keeping it warmer and still get fresh air in. then you could vent from the out side room into the grow room and then back outside.

have u ever heard of light intensity? sure u could raise up the light, cover a larger area, but ur loosing intensity. thats why movers r better too, u can put the lights right down to the plants and have a greater intensity, lumans/sqft or however u wanna measure it, without worryin about heat, and get the same results as the same light but never moves, having it 2' above the tops so they dont burn. but u can cover huge area

 

[ForbiddenFruit]

with 20 plants in the room, it will get really musky within 30 min. i thought the same thing, that u wouldnt have to vent all that much...

this is what ppl do with co2... while the lights are on, they will inject co2 up to 1500ppm for at most 20 min while the exhaust's off, any more co2 is a waste. then the stop injecting and turn the exhaust on. they let exhaust run for 1 or more hours, then repeat the cycle. no co2 during night. the co2 isnt suppost to be injected all day, and the room must be exhausted while lights are on and off. to much co2 will burn plants. not enough ventilation is unhealthy for plants, they would be better off with no co2 and full exhaust in my opinion, that is till u figure out a co2/exhaust schedual or get an environmental controller

Ahh.. I see. Very helpful post. Thanks!

I think I will skip on the CO2 this 1st time. Then read up on it and maybe give it a go the 2nd time around.

thanks again!

 

[ForbiddenFruit]

have u ever heard of light intensity? sure u could raise up the light, cover a larger area, but ur loosing intensity. thats why movers r better too, u can put the lights right down to the plants and have a greater intensity, lumans/sqft or however u wanna measure it, without worryin about heat, and get the same results as the same light but never moves, having it 2' above the tops so they dont burn. but u can cover huge area

I was thinking about getting this mover:

http://cheaphydroponics.com/store/view-all/intelli-drive-light-rail-3-5-6-rpm-w/-6-39-rail/prod_74.html

Would it be best at 6RPM or 10RPM(same cost either way)?

Also, I think I will get this extension kit as well, so I can run both of my 1000w lights on it:

http://cheaphydroponics.com/store/view-all/add-a-lamp-kit/prod_78.html

It's a straight rail system. 12' long with the extension.

Thinking of doing an aeroponics system, so I could just use fewer tubes and make them extra long in order to accommodate for this light set up. Still trying to figure all of that out though and taking it step by step.

Any thoughts?

thanks a million

 

[dbo24242]

thats right, you can exchange the air once in a while, or run a dehumidifier, and add co2

 

[LoudBlunts]

too much energy lost if you try to cool only your lights.

just pull intake from outside...or from ambient and then dump out the room.


you can be better enery efficient and cooling efficient if you just use that line to cool your grow

 

[dbo24242]

yea, use the garage for a buffer w/ cool air coming in, run the tubes into the attic and exhaust from the attic, you shouldn't need a direct line blowing that much cold air it will get very cold...

 

[stumps]

Don't ya think he will only be able to do that if he heats the outside room. If you pull that cold of air in, that room it won't stay 40 for long.
Thats why I was saying to use the lights to help heat the incoming air. Or am i missing something about heating the room? Ambient temps are very cold. if you run 5 deg air past 2 600 deg lights it should heat it up to at least frezing.

 

[LoudBlunts]

trying to cool lights with a/c is a waste

 

[stumps]

his outside temps are single digits
no ac trying to heat thing up some.

 

[ForbiddenFruit]

I think I will end up pulling air IN from the crawl space and then OUT into the attic. Crawl space being about 4' high and the attic a good 8'. Think I will run it directly through my lamps and then into the room. Bypassing the garage entirely. At least this way the area surrounding my grow room (the garage) will still maintain a moderate temp (in both summer and winter time).

Then, in the summer months, I will just redirect the air from my lights up into the attic, since heat would then be a problem.

Wintertime = Direct through the lights and into the room (to help warm it up).
Summertime = Direct through the lights and up into the attic (to remove that unwanted heat).

 

[stumps]

sounds like that will work. It would be good to get it set up and tested for temp before you add plants. That way you can tweek it before plants. just a thought.