OT - garage vent question

check your local building codes

Joe Piotrowski - Chicago Burb's

>

Re: check your local building codes

Eric M - San Jose

>I tried to find something on the city's code website, but couldn't find anything. It wouldn't be permanent, just something I could place in the vents during the winter months and remove during summer.

Re: OT - garage vent question

Robert Hutchins

>What sort of vents are you talking about? Are they in the door? Are they HVAC vents?

Re: OT - garage vent question

Eric M - San Jose

>They are above the concrete foundation, about a foot above the ground. There are 2 of them.

ventallation

Joe Piotrowski - Chicago Burb's

>I am no expert but unheated spaces need to be vented to reduce moisture buildup.

if these are just holes in the wall you should have no problem sealing them.

DO NOT COVER THOSE VENTS!!!

DB

>Those vents are vital to your safety and the proper operation of your GAS FURNANCE, GAS DRYER, GAS WATER HEATER. The vents allow enough air to reach the appliances so the oxygen level does not get to unhealthy levels. They also help keep the carbon monoxide levels down when the appliances are not operating properly.

Don't think so...

Hoa Dinh in Union City

>My garage has 2 vents like that.

I don't know what the vents are for, but they are not for any of the furnace, dryer, or water heater. All of them are in the laundry room, which is separated from the garage by a self-closing fire-graded door (code requirement). The frame of the door has weather strip to seal the door.

I have no plan to cover the vents. In fact, I'm finding a way to install a squirrel cage fan, using one of them as the exhaust. Even though I use shellac or water-borne poly, I'd like to have some ventilation.

-- Hoa

Re: OT - garage vent question

John Veerkamp

>A typical garage door lets in plenty of ventilation for combustion of your appliances. Unless your doors are sealed exceptionally well you can safely cover the vents during the winter. Their primary ppurpose is to provide air circulation to reduce heat and moisture buildup inwarm weather.

John

Re: DO NOT COVER THOSE VENTS!!!

Barry Irby

>As a Home Inspector I think the vents are for combustion air for the appliances and for make up air for the dryer. For years we RELIED on the leaks in our buildings to provide for makeup and combustion air. In tighter buildings and tight or small spaces the vents can be critical and are specified by the Local code. If your dryer and Water heater are in a large open space, enough air will leak in to satify both, but in a smaller tighter space, the dryer can easily suck air backwards down the flue of the water heater (or furnace). The fan on the dryer is much more powerful than the "draft" fo a natural draft device. Better to have them and not need them than to not have them and die. Its called back drafting and can be induced by a fan or even from poor venting practices. I have a friend that calls the down draft ranges "yuppy" killers.

Can't explain why the other garage has them unless there was indecision aobut putting a fired device in the garage or the hosue was remodeled.

Re: OT - garage vent question

Matt Robinette,Mt Juliet Tn

>I am not sure but if it a attached garage it could be for carbon monoxide venting for your cars.

Re: OT - garage vent question

Jesse in New Mexico

>I have two just like that in my garage. The builder said they were required by code for providing air to the gas hot water heater and the boiler for the radiant heat. On the other hand, when I asked the heating contractor, he said there was more than enough air coming in around he garage door for that purpose.

Being so confused (not unusual for me) I did a half-way solution and cut pieces of acrylic a little larger than the vents and put velcro on the walls and the acrylic covers. That way I can put them up if the weather is crazy or open them if I need a little ventilation in the shop.

Re: Hmmmm...

Kirk (KC) Constable

>No offense directed at you personally...but shouldn't a home inspector know the definitive answer to this question?

KC

Re: Hmmmm...

Barry Irby

>OFFENDED? Did you call me SHORT? :)

Kirk, it�s hard to know these things definitively. The post came from San Jose (CA?) and I am in VA. A continent and a world apart. I don�t know what Code his house was built under or how old it is. Until recently there were three regional model Codes like BOCA, SBCCI, and ICBO which have now melded into the International Residential Code. I actually don�t know if every state in the country has adopted any version of any of the codes. In some areas it has been traditional for local communities and counties to adopt whatever they chose as the �local� building Code. In some respects it is good, but there is also an element of the ridiculous. This country is so big and so diverse I wonder if we really need a National Code. CA might think the part on earthquake resistance is really important but here in VA we might wonder. In Florida they have Hurricane standards that might seem a tad over kill in Montana. They actually have an air powered cannon and shoot 2 x 4�s at windows to test them, but you might not want to buy those windows unless you are in tornado or hurricane alley.

In Florida, it�s fundamentally a cooling climate, but back in Montana, they worry more about heating. This has a fundamental effect on the placement of vapor barriers. In the deep south, vinyl wall paper can be a disaster because it cool on the inside and warmth and moisture are approaching from the outside and mold will grow under the wall paper. Probably never happens in Frost Bite Falls.

OTOH, CO is CO. I am 99% sure someone caused the builder to put those vents in that garage because they were assuring enough ventilation to serve the needs of the dryer and the water heater. That would work in Montana and in CA and in VA. I just don�t know if the locally applied Code specifically says �You will put two vents in the foundation wall of the garage� or some more general statement like �there must be X amount of net free vent area for Y btu�s of burner capacity PLUS Z more if there is a positive draft device such as a dryer.�

And example of the Code run amuck over �wording� is our local code for years said �all projecting (exterior) wood trim shall be flashed so as to be leak proof�. This was to keep water from leaking in and around trim and rotting the wall. Then they started making and shipping the high density foam trim. Since it was not WOOD builders stopped flashing above windows and doors. Things rotted. If the code had not specified WOOD and just said �all projecting trim� builders would have had to flash it, but common sense did not prevail. I have seen houses with thousands of dollars worth of damage.

Believe me, there is really nothing I would like better than to have a clear and concise Code that I could thump on like the Bible and say, YOU must do it like this, because this book says so. It�s just that �clear and concise� and �building code� are almost an oxymoron.

A CA home inspector might be able to quote Chapter and verse.

Question: �IF� numbers of people died in Hurricane Katrina from being trapped in their attic, does anyone know if they changed the locally applied Code to REQUIRE roof hatches?

Re: OT - garage vent question

Kneale Brownson in Northern MI

>All those gas burning appliances need air for their combustion processes. While their exhausts are "vented" to the outside, they may still require a fresh air makeup vent such as you describe. That may be their purpose.

The vents are for makeup air, but...

Dale Sherman - Manlius, NY

>...you could probably seal them up for the winter. To do so safely, though, it would be best to test the leakiness of the garage with a blower door. This would help quantify that you have enough leaks after sealing the vents to provide makeup air to your combustion products and the dryer. The national BPI standards say you should have no greater than -2 Pascals negative pressure (in the garage) in the worst case scenario, i.e., the dryer, furnace, and water heater all turned on.

You could place a flag on the switch of the dryer to remind you to open a vent when using the dryer.

You could also do your own test where you plug the vents, turn on the dryer, then turn on each of the combustion appliances and check for spillage at the hood of each appliance. If combustion gases are spilling out rather than drawing up the chimney, you likely need more vents to provide makeup air.

Disclaimer: All of the above is based on the perceived situation and may be inaccurate. An on-site visit and evaluation by a properly accredited professional who can accurately assess your particular situation would be your best recourse. I recommend contacting a BPI-certified contractor in your area.

Dale

Re: OT - garage vent question

DB

>If you are still considering covering up the vents, try using louvers like that are used on dryers. Just make sure that they will open when the air is pulled in from the outside. You are on your own trying to find what I just described.