Ventilation drawing air from furnace

Booga

Active Member
Hello RIU, winter has set in and the hole in my window i was using for passive intake is pulling in too much cold air. when i cover the holes in the window my grow tents seem to suck air from the furnace and it sets off my carbon monoxide alarms. the tents are in the room right next to the furnace room, the furnace room also has the window im venting in and out of. anyone have ideas how i could get my passive intake hole closed safely?
 

Booga

Active Member
its only when i close up the 4" hole im using for intake that the alarm goes off. dont think i can get a hvac guy in here unfortunately. the room the tents are in is surrounded by cement besides one wall that leads into the furnace room. the only other place i could get air from also shares a wall with the furnace area, i dont think it would solve the problem.
 

BigGreenThumb

Active Member
When you exhaust air out of your house, it has to pull the air from somewhere. It looks for the least path of resistance which in your case seems to be the chimney. You have to crack a window somewhere else in the boiler room (preferably) or basement
 

Booga

Active Member
thats what i figured but i was hoping someone had other ideas. its like -30 outside so having the crack in the window makes it very cold in my room
 

BigGreenThumb

Active Member
thats what i figured but i was hoping someone had other ideas. its like -30 outside so having the crack in the window makes it very cold in my room
why don’t you just run your exhaust to another area of the basement? The problem is being caused because you’re pulling the draft back through your chimney once you stop pulling the air from another outside source (in this case the 4” duct you mention). You can just run your passive intake within the room the tent sits in and exhaust to another area
 

Booga

Active Member
if im exhausting into a different room in the basement rather than outside would that help in some way?
 

Hiphophippo

Well-Known Member
Hello RIU, winter has set in and the hole in my window i was using for passive intake is pulling in too much cold air. when i cover the holes in the window my grow tents seem to suck air from the furnace and it sets off my carbon monoxide alarms. the tents are in the room right next to the furnace room, the furnace room also has the window im venting in and out of. anyone have ideas how i could get my passive intake hole closed safely?
Yeah man if your pushing co into your house your draft in your furnace isn’t working properly. Even if you open the ducking up you shouldn’t get co bleeding by your draft inducer or diaphragm valve. also sounds like your room is too air tight I know I know but if your not creating a point of air flow to come in and exit it’ll suck air from whatever gives first that being your heat ducting remember air is like water it’ll take the path of least resistance and if your room is that air tight your going to put stress on whatever it’s stealing it’s pressure from.
 

Booga

Active Member
if i seal the crack (4" hole) in the window i get the co from the furnace. the window is covered in ply wood and has 2 exhaust hoses going out and passive intake holes
 

Hiphophippo

Well-Known Member
So is the furnace draft pipe hooked up into the four inch hole or is it just a open hole that bleeds out furnace fumes openly
 

Hiphophippo

Well-Known Member
And if it’s hooked up your just pulling your furnace exhaust into your grow by having the pipes so close together which is also bad I would seal up my intake hole and draw air from the room not outside and just use the window as strictly exhaust no I take
 

Booga

Active Member
so the window the grow room exhaust blows out and the passive intake come in is about 10 feet away from the furnace closet cover thing. seems like the carbon monoxide is being drawn directly out of the furnace
 

myke

Well-Known Member
Your furnace should have an outside cold air supply all ready. It will go into the cold air return. Assuming natural gas forced air??
 

BigGreenThumb

Active Member
So is the furnace draft pipe hooked up into the four inch hole or is it just a open hole that bleeds out furnace fumes openly

Dude honestly this sounds very sketchy you have a furnace issue brother I would take care of that before dropping any money on your grow
its No issue other than I’ve explained above. If you have no fresh air coming in, the exhaust fan will pull the flue gases back down the furnace and into the tent because it’s the only place besides door and window cracks that air will get in. When you have other sources of fresh air (like the holes in the window that he is plugging up for intake) the furnace can exhaust freely with no backdraft. This could happen from a simple bathroom exhaust fan, let alone a big powerful in-line fan sucking large volumes of air out of the house.
It’s not a furnace issue… the tent exhaust and furnace are dueling for the fresh air. This just means he has a well sealed up and efficient house…
 

thumper60

Well-Known Member
its No issue other than I’ve explained above. If you have no fresh air coming in, the exhaust fan will pull the flue gases back down the furnace and into the tent because it’s the only place besides door and window cracks that air will get in. When you have other sources of fresh air (like the holes in the window that he is plugging up for intake) the furnace can exhaust freely with no backdraft. This could happen from a simple bathroom exhaust fan, let alone a big powerful in-line fan sucking large volumes of air out of the house.
It’s not a furnace issue… the tent exhaust and furnace are dueling for the fresh air. This just means he has a well sealed up and efficient house…
This is the correct answer!!!
 
Top