Vent to the outside

CraigMI

Hello.

I recently bought a house with steam heat. The boiler is in the basement. In the attached picture, you can see an insulated duct. At the top it is connected to a vent to the outside and it is open at the bottom. It's about 10 degrees here in Michigan, so cold air is pouring into my basement.

My question is, what is the purpose of this and can i cover it?

Thanks in advance.

Jamie Hall

It's probably there to bring combustion air into the boiler room. How bit is the boiler? How big is the space the boiler is in? And can the boiler draw combustion air from anywhere else in the house easily?

ChrisJ

The purpose of it is likely to bring combustion air to the boiler. Apparently your boiler room is too small and or too tight.

Now the bad news is, it's hard to tell with the insulation in the way but that boiler looks like it may be piped poorly....

Steamhead

It should be possible to put an automatic damper in that duct, with an interlock that won't let the burner start unless the damper is open. Kind of like a stack damper on an atmospheric gas boiler.

That gives me an idea- wire up a standard stack damper to a fan center relay?

AMservices

> @Steamhead said:
> It should be possible to put an automatic damper in that duct, with an interlock that won't let the burner start unless the damper is open. Kind of like a stack damper on an atmospheric gas boiler.
>
> That gives me an idea- wire up a standard stack damper to a fan center relay?

I did that.
The damper motor has an end switch that completes the call for heat aftet damper opens.

Just wanted to show @CraigMI an example

CraigMI

Thanks everyone for your feedback. The room is very small, so I'm sure you all are right.

A couple questions:

1. Is it ok to insulate the room to prevent the cold air from cooling the basement?
2. Could I temporary block the vent and leave the door open to the room?

Jamie Hall

CraigMI said:

Thanks everyone for your feedback. The room is very small, so I'm sure you all are right.

A couple questions:

1. Is it ok to insulate the room to prevent the cold air from cooling the basement?
2. Could I temporary block the vent and leave the door open to the room?

1. Yes
2. Probably not a really good idea...