Is it OK to vent to the attic?

curioushiker

curioushiker

Active Member
I will be running 4 1000w MH/HPS under large adjust-a-wings in a 20'x8'x7.5' room. Fresh air will be provided via a 12" max fan. My only pratical option for exhaust is venting to the attic. For those that have vented to the attic have you seen any side affects from doing so, like mold in the attic etc etc.
I tried attaching the ducting to the gable vent but it makes WAYYY to much noise.
Any help is mucha appreciated.
 
Supgee3

Supgee3

Well-Known Member
The only problem I can see is that after a heavy snowfall..... two hours later your house will be the only one with no snow on the roof...
 
Shrubs First

Shrubs First

Well-Known Member
thats fine, thats what most people do anyways.... either that or vent it in to house ventilation and it heats your house!
 
Alaric

Alaric

Well-Known Member
Hey bro,

Lot's of problem with mildew and smell when I did that.

Policy now-----install an attic ventalator and run about an 8" duct to it.

Also---put an inline ozone generator in duct.

A~~
 
1mikej

1mikej

Well-Known Member
i vent into my attic. i live in Florida and i was what they call super heating my attic. temps were 150f +. i bought a attic fan from home depot, not a whole house fan. this fan mounts over the vent on the attic wall. temps dropped to match outside temp and my living area dropped 5 degrees. and i vent my portables into attic. i would suggest taking temp readings in your attic during the hottest part of the day in the summer before you vent lights to make sure you dont already have a temp issue that you did not know about and check after you vent lights into attic. if temps are normal your good, if it gets hot vent attic with fan. mine was 100 bucks. also i ran the vent from my light as close as i could to the attic fan, i used a 25ft ac insulated ducting each box is 35 bucks at home depot. i hope my rambling on my set up helps.
 
curioushiker

curioushiker

Active Member
1mikej said:
i vent into my attic. i live in Florida and i was what they call super heating my attic. temps were 150f +. i bought a attic fan from home depot, not a whole house fan. this fan mounts over the vent on the attic wall. temps dropped to match outside temp and my living area dropped 5 degrees. and i vent my portables into attic. i would suggest taking temp readings in your attic during the hottest part of the day in the summer before you vent lights to make sure you dont already have a temp issue that you did not know about and check after you vent lights into attic. if temps are normal your good, if it gets hot vent attic with fan. mine was 100 bucks. also i ran the vent from my light as close as i could to the attic fan, i used a 25ft ac insulated ducting each box is 35 bucks at home depot. i hope my rambling on my set up helps.
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The fan that I am running is rated at 1709cfm. That is well over the recomended air exchange.
I know I will lose cfm's for bends in the ducting but I should still be well over the target cfm's.
I know the attic gets hotter than hell in the summer but I think with the CFM's that I will be pushing through the attic it shouldnt be a problem right?
 
curioushiker

curioushiker

Active Member
Alaric said:
Hey bro,

Lot's of problem with mildew and smell when I did that.

Policy now-----install an attic ventalator and run about an 8" duct to it.

Also---put an inline ozone generator in duct.

A~~
Click to expand...
Where your odor problems mold or the dank smell?
I tried venting right to the gable vent but it was way too loud to get away with that. I was told by a guy at the local grow shop that he ran his exhaust to the attic but stopped the end of the duct about Ten feet from the gable vent. He then made a tunnel with heavy plastic. The idea was that the fan would then blow through the tunnel allowing the air to expand in the tunnel. When it would finally exit the vent it was quiet. The tunnel not only allowed the air to expand and slow but it kept the humidity in the tunnel as well.
This sounds like a great idea but I dont want to go through the extra work if I dont need to.
 
curioushiker

curioushiker

Active Member
Supgee3 said:
The only problem I can see is that after a heavy snowfall..... two hours later your house will be the only one with no snow on the roof...
Click to expand...
It doesnt snow in Newport but it does get cold. Ice on the roofs and all. I have thought about this one....No way around it when in veg.
 
1mikej

1mikej

Well-Known Member
venting into attic is not a problem in its self. if your living area is not getting warmer and your ac is not running more don't worry about anything. but if it is the problem is the already hot attic getting hotter from the lights heats the rest of your living area and running up your ac bill. when you pump air into a room you pressurise it. the hot air actually gets pushed through seems into you living area. sound not but true its on the govt web site for insulating your house correctly. 2 solutions. 1 a exhaust fan for attic the pulls air out of attic and pushes it outside. 2 run the ducting from light in the attic to the soffit vent.
 
Alaric

Alaric

Well-Known Member
1mikej said:
venting into attic is not a problem in its self. if your living area is not getting warmer and your ac is not running more don't worry about anything. but if it is the problem is the already hot attic getting hotter from the lights heats the rest of your living area and running up your ac bill. when you pump air into a room you pressurise it. the hot air actually gets pushed through seems into you living area. sound not but true its on the govt web site for insulating your house correctly. 2 solutions. 1 a exhaust fan for attic the pulls air out of attic and pushes it outside. 2 run the ducting from light in the attic to the soffit vent.
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Oh---- to have a free supply of cold dry air is a wonderful thing.

The problem with 6x1Ks flowering in places like the sunshine state is heat-----especially running aero----nute temps = room temp if a chiller is added-----more cost and power---damn.

I had both mildew and smell problems before the attic ventalator and ozone were added. I used a 12"x25' duct for mixing the ozone before leaving the roof.

A~~
 
curioushiker

curioushiker

Active Member
I tried venting to the gable already but the 12" fan moves too much air for that vent. My gable vent is roughly 15' high and the air coming out of it moves the grass like a leaf blower. Plus it makes too much noise.
Venting to the soffit vents would be even worse. Believe me when I say I have thought this one through. I think the only real option for me is to buils the "tunnel" and place my ducting at the end of it.
The gable fans that you mentioned are a great idea. I think I will also look into the solar powered roof vents as well.
 
curioushiker

curioushiker

Active Member
Alaric;3442732 I had both mildew and smell problems before the attic ventalator and ozone were added. I used a 12"x25' duct for mixing the ozone before leaving the roof. A~~[/QUOTE said:
Do you have a line on the attic ventilator? Might same me some searchin.
Thanks.
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Alaric

Alaric

Well-Known Member
curioushiker said:
Do you have a line on the attic ventilator? Might same me some searchin.
Thanks.
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The 12" duct runs right up to the ventalator (Lowe's parts) from an insulated HVAC box I had built (same material used for return air in big systems).

The idea was to pull hot air from this 22' x 22' attic with a 6" space between the bottom of the ventalator and the 12" duct-----worked well during the hot summer temps.

Also ran flower lights from 11:30 pm till 11:30 am----enough morning time to service room.

A~~
 
growwwww

growwwww

Well-Known Member
Sorry to say this, but just consider if you are heating up your attic considerably the police use thermo-cams and look at that kinda shit in helicoptors...Just saying...
 
curioushiker

curioushiker

Active Member
growwwww said:
Sorry to say this, but just consider if you are heating up your attic considerably the police use thermo-cams and look at that kinda shit in helicoptors...Just saying...
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I have heard this many times. Where I live it is COMPLETELY LEAGAL to grow for medicinal use as long as one has the proper permit.
Is it not legal where you live?
 
1mikej

1mikej

Well-Known Member
there is nothing suspicious about an attic fan, in fact the govt recommends that you put 1 in you attic to cool it down. put the fan that cools your lights in the coolest spot that still provides sound free comfort and run ducting all the way to lights and run ducting from lights to a soffit vent or gable vent. if you push the air and you do long sweeping bends you wont loose to many cfm. if the fans inlet is not in your grow room you don't need to worry about smells. what i mean is the air that cools your lights should come from your attic or outside and it should return to your attic or outside. i run a 25ft ducting in my attic from a soffit vent to the inlet side of my fan and 25 ft ducting from fan to lights. the length of my house. then from my light another 25ft to my attic fan. i'm pulling air in from the left side of my house pushing it through my lights and out the attic fan on the right side of my house. the air in my grow room never mixes with the air cooling lights so there is no smell or humidity to grow mold. my lengths are long because i wanted no bends other than the ones coming out of ceiling into lights. if you use that big fan to pull the air out of the room where is the air that replaces it coming from? is it filtered? if its coming from the other room where is the air coming from that replaces that air , outside? im trying to make a point . lol. dont vent out your house! i was doing that for a year myself . your fan is huge it will clear you house out in ten minutes and now your ac has to cool and dehumidify all new air.
 
1mikej

1mikej

Well-Known Member
growwwww said:
Sorry to say this, but just consider if you are heating up your attic considerably the police use thermo-cams and look at that kinda shit in helicoptors...Just saying.
they look for multiple hot spots in a room that resemble grow lights. EVERY ONE'S ATTIC IS HOT IN THE SUMMER OR IN THE SOUTH. put a radiant barrier above your lights to defuse the heat so it just looks like a hot room instead of multiple very hot spots in 1 room. radiant barrier in your attics blinds cops.
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