I have a customer who has been in her house for a couple of years. The house was rehabbed by the local Community Rehab and she purchased it from them.
Since that time she has been fighting to get stuff corrected.
One of the problems she had was the ceiling in the furnace closet. Or rather the lack of a ceiling. The top of the furnace closet was simply open to the attic. She says that she was told that a framed drywall ceiling was impossible because the furnace needed marginal air. So the “ceiling” is now a foil like material taped around the edges.
The furnace ductwork goes into the attic. The cold air return is just a big vent in the wall of the closet. The door to the closet is fully louvered.
I don’t think I’ve ever even heard of the concept of marginal air. Is this concept legit? And what is it?
Thanks.
Rich Beckman
Another day, another tool.
Edit: correct “possible” to “impossible”. Although it seems everyone understood what I meant!
Edited 12/31/2004 4:42 pm ET by Rich Beckman
Replies
not legit .
poor a$$ work is all thats against code. call a state inspector
U sure she didn't mis-hear ... make-up air ...
or words to that effect ...
like the thing never shoulda been installed in closet because there's not enough intake air flow?
You need to start a list of "guys" ...
for this one ... I'd call Donny ...
my cell has voice dial ... so I'd open it and yell .... "Donny CELL" ....
my HVAC/ plumbing guy ....
he'll know for sure ....
I have a different guy for Allegheny County plumbing ... that's "Mike CELL" ....
what ya need ... I got a guy ...
throw them all your mechanicals work and they'll throw U and your customers good prices .... might even throw ya some carpentry work to boot.
Jeff
Buck Construction
Artistry in Carpentry
Pgh, PA
"U sure she didn't mis-hear ... make-up air ..."That is certainly possible. But I would guess this customer is more likely than most to understand what was said exactly."like the thing never shoulda been installed in closet because there's not enough intake air flow?"The door is fully louvered, top to bottom, and certainly has more clear air flow than the opening the furnace has for bringing in combustion air (not to mention the clear air flow of the 4" duct for combustion gases)."You need to start a list of 'guys' ..."If I have a list of guys, what would I ask about on Breaktime???Rich BeckmanAnother day, another tool.
Generally, some source of "make-up air" is required for a furnace that doesn't have a totally closed combustion system (with its own outside air intake). Also, code generally requires a louvered door on a closet for a combustion appliance (furnace or water heater).
But there's no need for the ceiling of the closet to be open to the attic. It would be sufficient for there to be a relatively small duct (probably 4-6", for a small furnace) from the attic, ending near the floor of the closet. Ideally the duct should end in a U, or end up in a sort of bucket, to help prevent a chimney effect.
Code Check calls out for two vents. One high and one low.http://www.codecheck.com/pg21_22mechanical.html#combustionairLook at figure m8.
That's if the closet is sealed. You just need makeup air if the closet is louvered.
Why doesn't the fully louvered door satisfy the diagram m7??Rich BeckmanAnother day, another tool.
Sorry I was focusing on the path to the ceiling and what I have (which is weatherstripped door and external vents).If the area is big enough and the space one the other side of the door is big enough then the louvered doors should be all that is needed.
Marginal air is what they provide you for respiration purposes on an aireoplane. They heat it, dry, add marginal amounts of various viruses, and diole it out to you at a rate barely sufficient to keep you alive.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
You forgot to mention the petroleum fumes.
I just know I couldn't be any sicker if i had spent the night in that closet sardined up against that furnace
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I'm with the others, she either misheard or her source of info misspoke or her source is plain screwed up.
The furnace needs combustion air (which some call makeup air - others call combustion air the air that goes into the flame and makeup air the air that gets mixed in with the combustion gases in the draft hood.)
Per building codes, the louvered door should provide sufficient air and the closet should have a ceiling.
BUT, the building codes don't always work, and in fact the fine print for venting says you can't rely on the codes (which rely on the venting tables which rely on software*) and the installer/service person is responsible for whether the system actually works!
Per my testing and that of other CO and combustion analysts, louvered doors don't necessarily (rarely according to some) provide sufficient air and the draft is too low.
I have tested several older, natural draft furnaces in closets with louvered doors which did not have sufficient draft with the door closed, and 1 80+ which had that problem.
I have tested many such without that problem - I wouldn't rely on a louvered door myself based on those tests.
Possible solutions:
Conventional: air vents - 1 sq in free vent space per 1000 BTU half top and half bottom bottom -
Unconventional solution: add a small register (partially opened) in the supply vent in the closet to pressurize the closet. Test with a draft gauge for adequate draft.
______
Venting table and venting table software disclaimers:
Venting table disclaimer:
LEGAL NOTICE: This information is, in part, a result of research performed by Battelle under the sponsorship of the Gas Research Institute (GRI). Neither GRI, members of GRI, nor any person acting on behalf of either:
a.) Makes any warranty or representation, express or implied, with respect to the accuracy, completeness, or usefulness of this information, or that the use of any apparatus, method, or procedures disclosed may not infringe privately owned rights;
or
b.) Assumes any liability with respect to the use of, or for any damages resulting from the any apparatus, method, or procedures disclosed
User precautions for the Vent II software:
"The user should realize that no safety factors have been included in the VENT - II calculation routines for vent capacities. The results will be reasonably accurate for new, well defined vent configurations under transient-cycling or steady - state conditions. However, the field performance of vent systems can be adversely affected by installation peculiarities, outside wind conditions, house tightness, leaky vents, other exhausting appliance, partial blockage of vent pipe, or other conditions. Therefor, appliance vent designer should use good engineering judgment in making allowances for the various perturbations which may occur in the field.
I don't know about yours, but my church isn't a hotel for the holy, it's a hospital for sinners
Sojourners: Christians for Justice and Peace
"Per building codes, the louvered door should provide sufficient air and the closet should have a ceiling."Could you explain the "ceiling" a little more.My house is 2 story on the slab and the lower level construction around the furnace is much like "finsihed basement". The inside of the closet is bare stud with insulation showing.The "ceiling" is bare joist with plywood sub-floor showing, except for two rectangular holes.I thought that there where miss cut for heating vents. But now I am wondering.One is under the linen closet on the 2nd floor and pathched.But the other one is open into the chase where the flue runs through the 2nd floor. I wonder now if instead of a miss cut that was one purpose.There is also a metal ductwork to brin in outside air. The outside wall is about 3ft under ground so that there is a single outside opening at the top and on the inside there is opening at the top and then it drops down and opens about 6" off the floor.
"Closet ceiling" - I suspect this varies from area to area but around here they don't allow openings between living spaces and the attic, presumably for fire spread reasons, EXCEPT they allow a combustion air supply register in the furnace room/closet to the attic!?! (Who said we have to be consistent or make sense?)In your situation it sounds like the holes were mistakes, although most codes require a high and low makeup air source so maybe they were thinking the opening in to the flue chase was the "high supply."Of course, the makeup sources are supposed to open to large volume areas, so if that was the idea it was a swing and a miss assuming the chase is pretty small. I don't know about yours, but my church isn't a hotel for the holy, it's a hospital for sinners
Sojourners: Christians for Justice and Peace
Thanks for all of the responses.I will go ahead and put in a ceiling without any vents and I'll make sure she has a Co detector in the house (I don't think there is one currently).When all the work is done, I will arrange to have the draft tested. Rich BeckmanAnother day, another tool.
I'd recommend including some vent - as I said, I don't like louvered doors (and testing now in cold weather can be "best condition because of higher drafts when it's cold.)And FWIW, as to CO monitors - I gave my views in message http://forums.taunton.com/tp-breaktime/messages?msg=31507.7One change: I am now selling a better low level monitor than the aeromedix unit I mentioned in that old message - the unit I've got sells for as much as $180, I sell it for $125, plus $5 S&HIt reads as low as 5ppm CO, has three stages of alarm and is battery operated so proper placement is easier.It also has the best sensor technology of any consumer CO monitor.I recommend this level of protection for people who are extra sensitive: elderly, infants, pregnant women (I recommend a full medical evaluation for pregnant men {G}) people with immune system issues or heart conditions, or people who want the best protection and safest possible environment.I
Sojourners: Christians for Justice and Peace
Bob,Thanks for the link to that thread. I remembered it and was going to hunt it down."Marginal Air, the official airline of Breaktime"I'm not sure why that is as funny as it is, but I'm laughing.Rich BeckmanAnother day, another tool.
"Marginal Air, the official airline of Breaktime"