Ventilation in cold shed

toast88

Member
I'm starting my first grow shortly but am concerned about this winter. I've built an insulated room inside a shed dont know how to keep smell down. A carbon filter with exhaust fan would be best but I dont want to have a heater running non stop. Could I just put a carbon filter and fan
inside the room and exhaust into the room. I realise there won't be any negative pressure. Asking for ideas to keep smell down without having a heater run non stop....anybody delt with this dilemma?
 

upnsmoke13

Well-Known Member
I have a two room out building that I use. Grow room (12x9) is insulated,sealed pretty good temperature & humidity controlled. Rest of 12x20 building is not regulated but has two vents. I have one vent with a screen but open, other is exhaust with a 6" fan & charcoal scrubber. Everything outside the building is clean & fresh but crack the front door and things are obvious!
My whole building has negative pressure so smell won't excape but my grow room is being cooled/heated without being exhausted continuously. I heat with a bathroom heater w/thermostat - don't judge me!
 

Roger A. Shrubber

Well-Known Member
if you've insulated the room, it should keep most of the smell in. no reason to run the fan all the time. it's not the smell in the room that's a problem, it's the smell out of the room. most people don't run their exhaust fan when the lights are off, unless they have a humidity issue.
 

JayBio420

Well-Known Member
Hello,

Since we don’t know how cold your winters are, a correct answer is hard to come by. If it’s below freezing, the heat from a large bulb may not be enough to keep a small room warm.

In that case, have a heater setup on a thermostat.

If heats not a problem, keep that warm scrubbed air around your lights in use.
 

toast88

Member
Hello,

Since we don’t know how cold your winters are, a correct answer is hard to come by. If it’s below freezing, the heat from a large bulb may not be enough to keep a small room warm.

In that case, have a heater setup on a thermostat.

If heats not a problem, keep that warm scrubbed air around your lights in use.
Minnesota winter
 

toast88

Member
I’m Canadian. How many minutes can you last outside without a jacket without dying? My city in the winter is less than 10 minutes...
We dont ty as cold as you but this past winter we had a 2 week cold snap that didn't get above 0 and hit -30 f
 

toast88

Member
I have a two room out building that I use. Grow room (12x9) is insulated,sealed pretty good temperature & humidity controlled. Rest of 12x20 building is not regulated but has two vents. I have one vent with a screen but open, other is exhaust with a 6" fan & charcoal scrubber. Everything outside the building is clean & fresh but crack the front door and things are obvious!
My whole building has negative pressure so smell won't excape but my grow room is being cooled/heated without being exhausted continuously. I heat with a bathroom heater w/thermostat - don't judge
Reason I need zero smell is 1 time a year someone comes to check on something in the shed and literally walks rite by the grow rooms door.
 

blowincherrypie

Well-Known Member
Im having a tough time picturing this.. where are you drawing air from?

Do you have advance warning when the person is going to be coming by to check?
 

toast88

Member
Im having a tough time picturing this.. where are you drawing air from?

Do you have advance warning when the person is going to be coming by to check?
The shed is for a generator that backs up a large hog barn I own. The company sends a guy out once a year to start the generator to see that it runs properly. I'd be pulling air from inside the shed as well as exhausting it into shed so during winter the vapor from exhaust would be seen. The room is air tight. The shed isn't so it would still be getting fresh air....I do not have any warning when he shows up basically I get a call saying I need to get into the shed to check generator. So I need the the shed with no smell and be able to not have to run heater all winter to run fan and exhaust....I'll be using leds so I wont get a whole lot of heat from to help out with heating.
 

Lordhooha

Well-Known Member
The shed is for a generator that backs up a large hog barn I own. The company sends a guy out once a year to start the generator to see that it runs properly. I'd be pulling air from inside the shed as well as exhausting it into shed so during winter the vapor from exhaust would be seen. The room is air tight. The shed isn't so it would still be getting fresh air....I do not have any warning when he shows up basically I get a call saying I need to get into the shed to check generator. So I need the the shed with no smell and be able to not have to run heater all winter to run fan and exhaust....I'll be using leds so I wont get a whole lot of heat from to help out with heating.
You may want to rethink where your growing if you don’t want run a heater in your situation. Honestly if the barn isn’t heated you may want to grow where the heat can stay constant.
 

toast88

Member
You may want to rethink where your growing if you don’t want run a heater in your situation. Honestly if the barn isn’t heated you may want to grow where the heat can stay constant.
I dont mind running a heater. I know I'll need it. I just dont want it running 24/7. What I need to find is a thermostat/controller that shuts off the exhaust fan if it gets to cold but has a back up timer built in so even if it is to cold the scrubber/exhaust turns on 5 minutes every so often just to keep the air fresh.
 

Lordhooha

Well-Known Member
I dont mind running a heater. I know I'll need it. I just dont want it running 24/7. What I need to find is a thermostat/controller that shuts off the exhaust fan if it gets to cold but has a back up timer built in so even if it is to cold the scrubber/exhaust turns on 5 minutes every so often just to keep the air fresh.
Dude you live in a stupid cold climate like I do. you are probably going to need that heater during lights on and off for sure. Even with all the insulation the heat will drop off quick your going to stress your plants from a roller coaster ride of hot and cold cycles. Your just going to have to suck it up and run the heater but nothing is for sure until the cold hits. What kind of leds are you running how hot will they get the room now while it’s not cold yet? Might get a better idea knowing that but I’m still going with your going to need that heater. Also what kind of insulation did you use for the shed?
 

blowincherrypie

Well-Known Member
yup what LH said.. plus you probably gotta take into consideration the rh spike when your temps drop.. You might be able to get by without heater during lights on, but on those days where the highs are below zero... idk brother
 

Lordhooha

Well-Known Member
Just to note in my Michigan basement newly built house (2011) maxed out insulation before my geothermal was installed for my house and grow rooms my rooms would drop an needed heat. It’s part of the reason I had a two zone geothermal system installed this way my house is heated one way and the other is to ensure my rooms stay nice an happy for my ladies. Colder climates just are slightly more expensive to do rather than warmer climates. Its just the nature of the beast growing in the north.
 

hotrodharley

Well-Known Member
Another thing, if you're down below freezing with a warm room inside a cold shed is you'll find every air leak! Condensation forms at all entry points, including outlets! Keep things clean or risk mildew/mold.
I live in Interior Alaska . -60F in winter. It is not possible to keep a space like this without ventilation. Molds thrive in sealed areas.
 
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