Old furnace vent Q's - with pics

[B20EF]

I recently bought a house built in 1973. Furnace is about 10 years old. The basement is colder than it should be. I noticed the vent in the corner of the furnace room. It vents onto side of house about 3 feet from front door and onto driveway. It looks like a dryer vent on the side of my house. The bottom of the stack is not seeled off and just pouring -30 air into my furnace room. The only thing on the bottom of the stack is a bug screen.
The new vent for the furnace now vents up through the roof.

Is this a neccesity for fresh air to the furnace? I was thinking it was the original furnace ventilation no longer to code. I would like to seal it off so cold air isnt coming into my basement anymore.

Thoughts?

http://i232.photobucket.com/albums/ee174/b18c_ek/Stack2.jpg
http://i232.photobucket.com/albums/ee174/b18c_ek/Stack1.jpg

[legendboy]

yes thats your combustion air

i would call atco to come do their free furnace check up and ask them when they are there

[CapnCrunch]

Shouldn't the open pipe be connected directly to the furnace?

[Tomaz]

Originally posted by CapnCrunch
Shouldn't the open pipe be connected directly to the furnace?

That's what I was thinking too...

I would also call atco about that. It seems very unnecessary. If anything, the new furnace will have it's intake and exhaust running in the same area, and connected directly. Again, double check with a pro before sealing that off.

['93 SR-V]

I think it neeeds to be there. My parents replaced their furnace about 5 yrs ago (house built around '86 it think) and when the guys did the furnace they put the same thing in.

[B20EF]

Thanks that makes sense. I'll call enmax and see if they do any free inspections because they are my gas provider. It does seem like it should be connected to the furnace for combustion air, because my basement floor is freezing. The bottom of my hot water tank is actually very cold to the touch because of it.

[blitz]

Mine is setup like that, but only a foot from the grill of the furnace. Installed last year and inspected by the city.

It has a much fancier end though, sort of a U shaped end that points the open section up. That seems to keep a draft out.

[codetrap]

I had an HVAC specialist come by and check out mine, and he agreed that it wasn't necessary, so I plugged mine up and sealed it off. Made the basement WAAAAY warmer. I was also concerned so I put a CO & NG detector in the furnace room to make sure I wasn't going to get bumped off in the middle of a cold night.

However, that being said, my house/furnace is different from yours.

[lauphman]

You can only remove it if you have a new high efficiency furnace which has its own 2 or 3 inch intake and exhaust pipes.

[Ven]

I have one too. Comes in right beside the furnace and dumps -30C air into the basement. Inspection sticker on it. My place is about 7-9 years old.

[mr2mike]

It has to be there. Can't remove it and plugging it IS against code.
Not saying don't block it, but you run some risks and you should know the risks.
CO2 detection is a start.

[cet]

Mine is open as well and has the exit near the furnace. As far as I know it provides fresh combustion air for not only the furnace but the hot water tank as well.

[CapnCrunch]

I have an older furnace and I don't have one of these pipes. Why do some people have them and others don't?

[botox]

Mines like that as well and is about 2ft from the furnace. House was built in 2006.

[eblend]

They make a special cover that goes on the end of those, and it connects to your furnace, so that when the furnace runs it allows air through, but blocks it otherwise. Seem it on DIY network before, can't for the life of me remember the name of the device.

[Porsche_55]

looks like fresh air intake.

[Maxt]

Unless you are will to do a complete retrofit to new appliances that are sealed combustion , get one of these:
http://www.hoyme.com/

And don't for the love of god seal it off, unless you want to be a newspaper headline...

[ianmcc]

+1 for the Hoyme damper. We installed one when we first moved into the hose since the basement got fricken cold due to the wide open cold air intake. Plus it was really simple to install.

[eblend]

Originally posted by Maxt
Unless you are will to do a complete retrofit to new appliances that are sealed combustion , get one of these:
http://www.hoyme.com/

And don't for the love of god seal it off, unless you want to be a newspaper headline...

Thank you, that is the exact thing i was talking about in my post. I knew it sounded something ending with e....howie ect, tried it all in google before giving up haha

[codetrap]

Meh, mine's been sealed off for 2 years now. Still not in the headlines... *sigh*

[B20EF]

Thanks for the tip on the hoyme products. Good to know that vent is supposed to be there. Odd that none of my houses I grew up in had one.

[Maxt]

It used to be classified by loose construction or tight construction. Loose Construction was pretty typical in old buildings, people weren't to worried about energy efficiency, so doors had 1/2" gaps and no sweeps. Windows didn't seal worth a crap so enough air got around for combustion, attics werent sealed, etc etc...
Lots of those old houses have been reno'd and tightened, vapour barriers added, sealed unit windows, and tight doors, then the combustion air problem starts to show. Those kind of upgrades get done typically before the appliances get upgraded.
Sometimes the furnace will draw backward through the hot water tank, the dryer, I have even seen frost built up on a built in vacuum system from back draft. The problem really shows, when the furnace starts to malfunction, you get a cracked exchanger, the combustion goes all to hell and tips more towards CO production than C02
Look at it like this, say your combined appliance input is 200,000 btu/hr, the calorific value of our gas is 1000 btu/cuft, so in one hour of run time you burn 200 cuft of gas, which has a stoich of 10:1 so you need 2000 cu ft of air then add 10% excess air for draft so 2200 cuft for one hour of burn time. Thats a lot of air to suck through cracks...

[CapnCrunch]

Originally posted by Maxt
It used to be classified by loose construction or tight construction. Loose Construction was pretty typical in old buildings, people weren't to worried about energy efficiency, so doors had 1/2" gaps and no sweeps. Windows didn't seal worth a crap so enough air got around for combustion, attics werent sealed, etc etc...
Lots of those old houses have been reno'd and tightened, vapour barriers added, sealed unit windows, and tight doors, then the combustion air problem starts to show. Those kind of upgrades get done typically before the appliances get upgraded.
Sometimes the furnace will draw backward through the hot water tank, the dryer, I have even seen frost built up on a built in vacuum system from back draft. The problem really shows, when the furnace starts to malfunction, you get a cracked exchanger, the combustion goes all to hell and tips more towards CO production than C02
Look at it like this, say your combined appliance input is 200,000 btu/hr, the calorific value of our gas is 1000 btu/cuft, so in one hour of run time you burn 200 cuft of gas, which has a stoich of 10:1 so you need 2000 cu ft of air then add 10% excess air for draft so 2200 cuft for one hour of burn time. Thats a lot of air to suck through cracks...


Ohhhhhh, that makes perfect sense. Thanks.

[codetrap]

So, anyone actually buy that power vent thing? If so, how much and where? I got curious again since I couldn't remember how chilly it got, so I pulled the tape off the vent and now the basement is getting cold again. So, I figure I'll go the safe route and put that vent controller on it instead of the cold air "bucket".