Does the outside vent have a flap? if the flap opens to allow air IN or these is no flap, I would not remove it.
I will assume it has a screen to prevent varmint ingress.
What is this?
- Thread starter Sonic
- Start date
I will assume it has a screen to prevent varmint ingress.
No wood burning stove here. House is 19 years old. I remember asking what this was to the home inspector. He had no clue. Which if it’s a necessary item in this house you’d think a local home inspector would have seen this before. We’ve lived in newer and older homes and never had anything like this anywhere else. Gas furnace does have a dedicated air intake to outside. Return air duct also pulls air from the outside as well. The gas water heater though is just a power vent to exhaust outside. No intake. Idk, maybe I can just shorten this hanging flexible duct leaving it but so it’s smaller.
Previous dude had a hobby solder or glue or paint or whatever bench set up there.
On the bench he had a fan or hood, and hose attached.
Does not explain the insulation, but, hmmmm...
On the bench he had a fan or hood, and hose attached.
Does not explain the insulation, but, hmmmm...
Last edited:
I'd say it was makeup air for furnace/water heater that was installed before the new furnace. Since it appears to be tied off at the bottom, I'd say it's not doing anything at the moment.
It also could be for the Radon system, since they will cause a negative pressure in the house. Since it is open near the floor and that's where Radon is usually encountered, that makes more sense. Reading now about your power vented water heater, that MIGHT also benefit from makeup air.
No reason in the world why it would be insulated though. And of all things, why would it be in that location unless they want cross ventilation.
It also could be for the Radon system, since they will cause a negative pressure in the house. Since it is open near the floor and that's where Radon is usually encountered, that makes more sense. Reading now about your power vented water heater, that MIGHT also benefit from makeup air.
No reason in the world why it would be insulated though. And of all things, why would it be in that location unless they want cross ventilation.
It is exactly what I said it was in an earlier post. I have seen a pail at the bottom to reduce cold air on the floor. You might want to check code before your plug or remove.
Combustion Air Ducts, Part II: Problems and Solutions
By far, the most common problem that occurs with combustion air ducts is that they get blocked. When a combustion air duct is blocked, air needs to leak in to the house through many different undesirable pathways.
structuretech.com
Combustion Air Ducts, Part I: Why Houses Need Them
Homeowners, builders, and insulation contractors spend lots of time trying to seal up every little air leak in to a house, but then the building code requires this big hole that allows cold air to just dump in to the basement. Silly, right?
structuretech.com
- Joined
- Jun 22, 2022
- Messages
- 1,011
My house doesn't have a dedicated make-up air vent. I suspect the indoor air pressure is balanced through the bathroom ceiling vents or the dryer ventIt is exactly what I said it was in an earlier post. I have seen a pail at the bottom to reduce cold air on the floor. You might want to check code before your plug or remove.
Combustion Air Ducts, Part II: Problems and Solutions
By far, the most common problem that occurs with combustion air ducts is that they get blocked. When a combustion air duct is blocked, air needs to leak in to the house through many different undesirable pathways.
Combustion Air Ducts, Part I: Why Houses Need Them
Homeowners, builders, and insulation contractors spend lots of time trying to seal up every little air leak in to a house, but then the building code requires this big hole that allows cold air to just dump in to the basement. Silly, right?
Is it an exhaust fan type set up where that other hose might be an intake for air to flow across the basement. (Just grabbing at straws here)
I am thinking this duct is for air ingress to offset negative indoor pressure and provide combustion air for the GF WH. If the air "sucked in" is below the dew point condensation will form on the outside wall of the pipe so it is insulated.
To you point- The smell of burning rosin in the morning smell's like ... HEATHKIT !
Or an exhaust hose for a portable standalone AC
Good point. That dots the eyes and crosses the t's.
Most houses in the upper midwest have them. Your furnace and gas water heater are drawing air for combustion and with how tight the houses are these are necessary. usually at the bottom you would put an elbow to form a u to prevent a draft.
Similar threads
