matt151617

I have a large vent (approximately one square yard) at the very top of the basement stairs. There is a closet on the other side of the vent. The closet is very cold and I feel like this vent is the cause. Does anyone know why this vent is here, and can I drywall over it? The basement is not finished and not heated, although it looks like it was heated at one time.

Mingledtrash

Its likely a return air vent for your basement hvac. find out where your hvac units are located and see if they have return air pulling throught the walls or closet.

Some times you get shoddy/lazy people doing stupid stuff with return air.
Here is one example How not to install a return air.
https://www.nachi.org/forum/f20/not-...urn-air-60822/

matt151617

I don't have air conditioning and the heating system is baseboard hot water, so it can't be that. Maybe the idea is to give an extra air source for the boiler burner? The closet is maybe 5'x3' so I can't imagine it'd provide much air.

Mingledtrash

If there is one in the other side of this wall yes. They usually require one at the bottom and one at the top for gas water heaters and such. I can tell its old just by the design/style of the vent. if it is for a water heater or boiler you might need to add more venting you need one down low too.

supers05

Is the area that you're standing in while taking that picture cold also? You sure that is the only vent to that closet? Do you know or see evidence that there was a gas hot water tank or something similar in there?

I'm asking because, my first thought is that there may be fresh air vent in that room, communicating to outside.

Short of that, I can't imagine that the closet would be noticeable colder then the floor around it, if the top of the stairs isn't very cold.

Cheers!

matt151617

Where I'm standing is the kitchen- just inside of that door (on the steps), it is cold. But it's an unfinished, unheated concrete basement so that's to be expected.

The house was all electric when I bought it 5 years ago, except for the boiler which was heating oil. The hot water was made off of a coil on the boiler. I don't see anything that indicates there was ever a hot water heater in there, or any other vents on the outside walls, but the closet is carpeted and drywalled so who knows. The house was built in 1952, so a lot could have changed since then.

I guess the only real solution here is to cover the vent with plastic and see if that makes it any warmer. If not then I probably have to tear out the drywall and see what is behind it.

Mingledtrash

Another possibility is that you dont have enough airflow in the basement. you are required to have a certain amount of window and or air handling equipment to move fresh air into your basement for breathing.

Do you have HVAC in the basement?

Chances are that when the house was built in 1952 they did not have a HVAC unit to move air through the house and you probably dont have enough openable windows in the basement.

supers05

So? The OP already stated that it was an unconditioned space, and doesn't use it. Clearly that means that there little to no hvac air flow, and he's fine with that. Closets are usually not considered habitable either.

Where's that excerpt from anyways, you didn't cite the source. Since we all live in different jurisdictions, this matters, as it probably does not apply to many of us.

Cheers!

SeniorSitizen

No idea what the vent is for but in a heated structure for cold air to enter there must be a way for warm air to exit. Place a smoke stick at the vent to determine which way the air is flowing.

matt151617

I have plenty of windows in the basement, but never open them. It pretty much stays the same temperature year round.

Great idea on using smoke to see where the air flow is going.

Mingledtrash

Lol the concept of this code snippet applies to everyone as we all tend to need to breath.

Anyway its from the international code. sorry i didnt cite it. International code is adopted in all fifty states in the u.s. OP profile says new york. new york could possibly be stricter.(would prob if anything require more ventilation.)

The closet may not be habitable, but i would bet that the vent was to get air to flow out of the basement, which is probably habitable, into the closet and out whatever vent or return air is on the other side, or was there in the past.

the house is old as sh!t so, there is a possibility none of us will ever know what the vent was for or if it was connected to some other vent in the past. the vent cover it's self is old as sh!t you can tell by the style. they dont make em like that anymore.

So the purpose of me posting the code was to try and provide some context to why the vent may or may not be needed there and also to help determine if it can be removed.

Again my apologies for not citing properly.

IRC Link to code post in previous post.
http://publicecodes.cyberregs.com/ic...?bu2=undefined