DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   HVAC (http://www.diychatroom.com/f17/)
-   -   Furance room ventalliation (http://www.diychatroom.com/f17/furance-room-ventalliation-31453/)

n0c7 11-08-2008 08:52 PM

Furance room ventalliation
 
I finished my basement and my furnace room is blocked off. The only access into it is a bi-fold closet door with a 3/4" space at the bottom. Does the furnace room need airflow? It has a fresh air duct from outside. It definitely gets warm in there when the furnace is running. I don't care if its warm or cold in there as no one is ever in there but I don't want to have any negative effects in the HVAC system due to this.

hvac122 11-08-2008 09:57 PM

What you equipment needs is combustion air. The fresh air that you mentioned, does it connect to the ductwork or just dump into this room?

If connected to the ductwork then it is fresh air for you house, which is good, but is not combustion air. Your furnace and water heater need air to burn. If not provided then they could backdraft the flue and put carbon monoxide into your house. There are a few ways to do this. You could dump air into the room from the outside or if there is enough area open in the basement you could install a louvered door or put grilles high and low to get enough air. Codes differ depending on where you live so I would call a hvac expert to size this for you.

You could have a potentialy dangerous situtation here that needs to get repaired right away.

hvaclover 11-08-2008 11:19 PM

Why didn't you just put a louvered bi fold door?

n0c7 11-09-2008 01:48 AM

Quote:

Originally Posted by hvac122 (Post 182134)
What you equipment needs is combustion air. The fresh air that you mentioned, does it connect to the ductwork or just dump into this room?

If connected to the ductwork then it is fresh air for you house, which is good, but is not combustion air. Your furnace and water heater need air to burn. If not provided then they could backdraft the flue and put carbon monoxide into your house. There are a few ways to do this. You could dump air into the room from the outside or if there is enough area open in the basement you could install a louvered door or put grilles high and low to get enough air. Codes differ depending on where you live so I would call a hvac expert to size this for you.

You could have a potentialy dangerous situtation here that needs to get repaired right away.

The air dumps into the furnace room from outside. As far as I can see, there is nothing directly connected to the HVAC from the outside, although their may be an intake connected but I will have to look harder. There is basically a flexible hose that runs to the furnace room that you can smell and feel air from the outside entering. Is this sufficient? Basically the only thing I changed from the home design was instead of having the entire basement wide open to fill with fresh air from outside, I've now confined the space around to furnace room in theory allowing even more fresh air for the furnace and water tank. When I had the city here to inspect I explained my setup and they said it was ok to close it off the way I did as I left the fresh air source inside the furnace room, but I don't trust one persons opinion with safety. I have a carbon monoxide detector that I leave on the floor in the furnace room and it hasn't even registered a reading yet. Is there a better location for it besides the furnace room? Attached is a picture of the furnace room with the air ducting coming in from the outside:

http://i62.photobucket.com/albums/h82/n0c7/DSCN0572.jpg

n0c7 11-09-2008 01:50 AM

Quote:

Originally Posted by hvaclover (Post 182159)
Why didn't you just put a louvered bi fold door?

See my post above, but to sum it up I was told that my setup was fine as long as I left the fresh air within the closed off area. It just seems too warm in the furnace room now is the only issue. Also, a louvered door didn't quite match cosmetically and if need be, I would rather cut one or two grills into the bifold that matches(if it comes to that).

coolmen 11-09-2008 01:10 PM

the setup is installed to solve the lack of cumbstion air problem.seal the air leaks in the mechanical room supply and return.metal tape or mastic paste.insulate the plenum.

Yoyizit 11-09-2008 01:25 PM

scrounged this up
 
a GAS-FIRED water heater making a puffing sound needs more combustion air.

and

A building of "ordinary tightness" needs 50 cu. ft. per each 1000 BTU/hr input, so a furnace of 167,000 BTU/hr needs to be able to draw air from a room at least 33' x 33'.

n0c7 11-09-2008 02:03 PM

Quote:

Originally Posted by Yoyizit (Post 182354)
a GAS-FIRED water heater making a puffing sound needs more combustion air.

and

A building of "ordinary tightness" needs 50 cu. ft. per each 1000 BTU/hr input, so a furnace of 167,000 BTU/hr needs to be able to draw air from a room at least 33' x 33'.

Everything appears to be operating normally, no puff noises. So in the case of an enclosed room, where and how does it draw that air from?

n0c7 11-09-2008 02:19 PM

Also, I went outside and we have two fresh air intakes side by side. I know one of them is in the picture and the other I'm guessing must goto the furnace. There is a pipe that is split between the furnace and hot water tank.

hvac122 11-09-2008 02:25 PM

As long as it is sized right it looks like you have combustion air and should be ok. As said you should seal the ducts at least in the furnace room.

The carbon monoxide detector, I would put in the hall by your bedrooms and also have one in or around the furnace room. Make sure that you buy a good one. Most only read 40PPM or higher and only alarm if you have a constant 40PPM for four hours. You can get flue like symptoms at 9PPM so don't get the cheapest. They only last for 5 years also so replace at that time. The test button only checks the battery.

n0c7 11-09-2008 03:29 PM

Quote:

Originally Posted by hvac122 (Post 182370)
As long as it is sized right it looks like you have combustion air and should be ok. As said you should seal the ducts at least in the furnace room.

The carbon monoxide detector, I would put in the hall by your bedrooms and also have one in or around the furnace room. Make sure that you buy a good one. Most only read 40PPM or higher and only alarm if you have a constant 40PPM for four hours. You can get flue like symptoms at 9PPM so don't get the cheapest. They only last for 5 years also so replace at that time. The test button only checks the battery.

There are no ducts in the furnace room that are open, however I built an office right outside of the furnace room. Basically, you have to enter the office to enter the furnace room. Inside this office is a hot air register(closed because its warm enough with the furnace next to it) and a cold air return in the ceiling. The office also has a 30in door which even further cuts off air to the furnace room.

As for the carbon monoxide detectors, I'm off to buy a couple new ones. Maybe I should place one in the office as this is nearest? I've ready varied opinions for placement. Some say not to have it within 5 ft of any gas appliance and others say ceiling placement is the best. Any opinions on that?

1610 CUB 11-09-2008 04:53 PM

Well, Well we got that furnace all hid away, all out of sight ya know! But wait it has broken down, how will we ever get to it , or Sir you need a new furnace but the walls prevent us from getting to all the fasteners! Sorry its a pet peeve......... j

n0c7 11-09-2008 06:11 PM

Quote:

Originally Posted by 1610 CUB (Post 182408)
Well, Well we got that furnace all hid away, all out of sight ya know! But wait it has broken down, how will we ever get to it , or Sir you need a new furnace but the walls prevent us from getting to all the fasteners! Sorry its a pet peeve......... j

I was smart enough to measure the appliances and door frames ;)

1610 CUB 11-09-2008 06:54 PM

Quote:

Originally Posted by n0c7 (Post 182433)
I was smart enough to measure the appliances and door frames ;)

Can you get to all sides of the duct work? Have you put a wall right behind the furnace?:whistling2:

hvaclover 11-09-2008 07:01 PM

Quote:

Originally Posted by n0c7 (Post 182433)
I was smart enough to measure the appliances and door frames ;)

it sounds like you are referring to moving the appliances only. I think what 1610 cub was referring to is how much room did you leave to service the furnace, or or is the wall butt tight against the front of the furnace.


All times are GMT -5. The time now is 02:04 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved