Heating my home with exhaust from cool-tubes. Need some advice...

brews_willis

New Member
I am currently running a new closet setup that runs 2x 600 Watt 8" Cooltubes, the grow is going great however I made the mistake of venting into the attic when I setup the room up a couple months ago. Now it's winter and the temps outside will be below freezing for the next 4-5 months, I'm noticing some frost forming on the inside of roof sheeting and I know I need to change where I'm exhausting. I live in a manufactured home and too me the easiest and possibly the best place for me to exhaust the warm light air would be into the space where the furnace intakes air. My furnace intake is built into a space in the wall of my home, so my idea was to blow the warm air from the light exhaust into the intake space in the wall through the ceiling of the space. I'm planning on using 8" insulated flex duct to run from where I currently exhaust into the attic then down through the ceiling of the intake space (which is sealed from the attic and only draws air from the inside of my home) via a flange. The air would be dumping into the space beside the furnace intake filter and when the furnace is not running the air would be pushed out throughout the homes ducting and through the intake vent on the wall for the furnace. I am using an 8"HO Can fan to push my exhaust, its rated at 766CFM.

Does anyone see a problem with this? I have read other posts where people are heating their homes with their lights, but my situation seems a bit different with the way the furnace intake is built into the houses wall space. All the warm air from the lights will be accessed by the furnace on the intake side, not on output side of furnace, it also does not bypass the furnace air intake filter. Smell is not a concern at this point as I'm using a CANFAN 66 carbon filter which is also rated for my exhaust fans output cfm. Humidity is way higher outside than inside where I live during the winter, of course in the summer I may just vent back into the attic not having to worry about the much colder air on the outside of the roof/attic.

Any thoughts on what I'm planning will be appreciated.
 

Cannasutraorganics

Well-Known Member
I am currently running a new closet setup that runs 2x 600 Watt 8" Cooltubes, the grow is going great however I made the mistake of venting into the attic when I setup the room up a couple months ago. Now it's winter and the temps outside will be below freezing for the next 4-5 months, I'm noticing some frost forming on the inside of roof sheeting and I know I need to change where I'm exhausting. I live in a manufactured home and too me the easiest and possibly the best place for me to exhaust the warm light air would be into the space where the furnace intakes air. My furnace intake is built into a space in the wall of my home, so my idea was to blow the warm air from the light exhaust into the intake space in the wall through the ceiling of the space. I'm planning on using 8" insulated flex duct to run from where I currently exhaust into the attic then down through the ceiling of the intake space (which is sealed from the attic and only draws air from the inside of my home) via a flange. The air would be dumping into the space beside the furnace intake filter and when the furnace is not running the air would be pushed out throughout the homes ducting and through the intake vent on the wall for the furnace. I am using an 8"HO Can fan to push my exhaust, its rated at 766CFM.

Does anyone see a problem with this? I have read other posts where people are heating their homes with their lights, but my situation seems a bit different with the way the furnace intake is built into the houses wall space. All the warm air from the lights will be accessed by the furnace on the intake side, not on output side of furnace, it also does not bypass the furnace air intake filter. Smell is not a concern at this point as I'm using a CANFAN 66 carbon filter which is also rated for my exhaust fans output cfm. Humidity is way higher outside than inside where I live during the winter, of course in the summer I may just vent back into the attic not having to worry about the much colder air on the outside of the roof/attic.

Any thoughts on what I'm planning will be appreciated.
I do something close. But 5 1000 watts. I would change the intake to the inside of the house. Do you have attic space or just under the house?
 

whitebb2727

Well-Known Member
When I run in the basement I block the heat vent. You would be surprised how well it heats a room.

My inlet is close to the floor and outlet up high. I just exchange the air in the room.
If it gets a little warm I crack the window and the cool air settles and goes in to the box.
Good for bringing out colors in flower.
 

THE KONASSURE

Well-Known Member
when your lights are on if your using a gas furnace then the extra o2 may even help its efficiency

Does anyone ever use their heating or hot water boiler to supply co2 to their grow ? I`d think the potential danger of other emissions would put most people off but loads of people running co2 when their boiler is making it for free, lol
 

jijiandfarmgang

Well-Known Member
If it is winter outside the air outside is drier. The reason frost is forming in your attic is because while the air exhausting may have a low rh, but its relative to temp, and the drop in temperature causes the rh to skyrocket. The cold sheeting is below the dewpoint and causes moisture to come out of the air (condensation).

I have a friend that heats his whole home with his lighting ( a lot more than 1200 watts). Think hot grow rooms cold house. A similar issue to your attic. The grow rooms had an acceptable RH but it was humid as hell in his home. His new double pane windows were sweating like crazy and had mold on his window trim. He blamed the issue on organic window stain, and plugged in a box store dehumidifier and acted like problem solved lol.
If he would only turn the heat up in his home.

- Jiji
 

Diabolical666

Well-Known Member
I wouldnt run hot air into my heater intake area, might stress out your heater. Run the tube threw the wall and exhaust out of a vent. diy
 

brews_willis

New Member
Ok thanks for all the replies so far.
I do something close. But 5 1000 watts. I would change the intake to the inside of the house. Do you have attic space or just under the house?
My grow room is setup with fan inside blowing through the cooltubes and exhausting into attic. So the room is the intake so I guess technically it is in taking from inside my house. I do it this way to create a negative pressure in my grow room an temps are right on par at 75f solid.
 

brews_willis

New Member
Pulling cold wet air through the lights is bad. The idea is to remove the moisture and control the heat.
I'm not pulling cold wet air though my lights. It's just grow room air going through the lights, but it becomes cold and wet once that air is exhausted into the attic, which is what I'm looking to change.
 

brews_willis

New Member
If it is winter outside the air outside is drier. The reason frost is forming in your attic is because while the air exhausting may have a low rh, but its relative to temp, and the drop in temperature causes the rh to skyrocket. The cold sheeting is below the dewpoint and causes moisture to come out of the air (condensation).

I have a friend that heats his whole home with his lighting ( a lot more than 1200 watts). Think hot grow rooms cold house. A similar issue to your attic. The grow rooms had an acceptable RH but it was humid as hell in his home. His new double pane windows were sweating like crazy and had mold on his window trim. He blamed the issue on organic window stain, and plugged in a box store dehumidifier and acted like problem solved lol.
If he would only turn the heat up in his home.

- Jiji
That may be the case in some parts of the world, but we're im at its a pretty solid 70-80% RH outside for the majority of the winter where as in my house it's about 20-30%. But either way the exhaust air shouldn't be going into the attic. I think with the RH numbers I've said above, the mold problem with heating my house with the lights shouldn't really be an issue. If it does become an issue, the house has a main exhaust fan that exhaust the whole place outdoors.
 

brews_willis

New Member
I wouldnt run hot air into my heater intake area, might stress out your heater. Run the tube threw the wall and exhaust out of a vent. diy
I appreciate your reply and it's these types of concerns that I worry about. But coud you elaborate as to how warm air could cause stress on my furnace? I would think it would do the opposite by taking some of the heating load off, but I don't know a whole lot about furnaces other than the basics.
 

brews_willis

New Member
In
That may be the case in some parts of the world, but we're im at its a pretty solid 70-80% RH outside for the majority of the winter where as in my house it's about 20-30%. But either way the exhaust air shouldn't be going into the attic. I think with the RH numbers I've said above, the mold problem with heating my house with the lights shouldn't really be an issue. If it does become an issue, the house has a main exhaust fan that exhaust the whole place outdoors.
in fact it is so dry in my house that it cause me exzyma/psoriasis.
 

Diabolical666

Well-Known Member
Its kinda like blowing hot air on a ballast, its not going to run very efficiant, and will run harder. HVAC is usually placed in a drafty space so it can get cool air intake.
 

brews_willis

New Member
Its kinda like blowing hot air on a ballast, its not going to run very efficiant, and will run harder. HVAC is usually placed in a drafty space so it can get cool air intake.
While I totally understand how a fan blowing on a ballast is a problem because of the heat wicking and how that effects the electronics. I don't see how that would effect a gas furnace. My understanding of gas furnaces is that a thermostat trips the gas valve to ignite the burners and then a fan kicks in to disperse the heat. Whether the air is warm or cold, I don't see how it would effect anything inside of a furnace? Burners will still burn natural gas and the fan will still blow warm air? You aren't wicking heat away from parts like capacitors and diods like you do when blowing air over a ballast? Correct me if I am wrong please. Wouldn't be the first time lol.
 

jijiandfarmgang

Well-Known Member
The RH is higher outside but the absolute humidity is lower.

but yeah, I don't think you will run into humidity problems in your home at all.

- Jiji
 

bamboofarmer

Well-Known Member
I wouldnt run hot air into my heater intake area, might stress out your heater. Run the tube threw the wall and exhaust out of a vent. diy
I don't think the warm air will hurt the furnace, but the humidity of the air could cause some rusting inside of your heat exchanger. I think I would just exhaust through an interior wall as per diabolical666's advice.
 

Cannasutraorganics

Well-Known Member
I just dump into hall near heater intake and run just the fan to circulate the warm air through the house. Could put blower for heater on timer. And if you haven't read recently, the room with lights on should be 83-85.
 
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