Page 2 of 3 FirstFirst 123 LastLast
Results 14 to 26 of 28
  1. #14
    Join Date
    Feb 2004
    Location
    Central Kansas
    Posts
    1,145
    The MAV's are only to be piped using two pipe systems, while the newer AAV units are approved for one or two pipe. We've just put in a few recently. Old habits die hard and the theory of not using inside air for combustion that the homeowner paid to heat is instilled in my mind as the only way to go.
    Don't confuse me with facts, my mind is already made up.

  2. #15
    Join Date
    Jun 2005
    Posts
    40

    Clarifiction--Not done yet

    Install is still occuring. HELP!!! please. The unit is a 355AAV so this is approved for the one pipe and air intake method?

    [Edited by acam on 10-31-2005 at 09:24 PM]

  3. #16
    Join Date
    Nov 2004
    Posts
    2,927
    Originally posted by bigbird
    I`m reading the specs on the 355mav & no where in the specs. vent table is there a mention of drawing comb. area from the area around the furnace. All the vent tables call for 2 pipe system.
    I have not looked it up.So lets assume bigbird has his reading glasses on,and isnt playing a halloween prank,and is correct...then you have a code violation that could be handled through the city inspector if need be.

    It would be better to draw combustion air from outdoors.your furnace will thank you.

  4. #17
    Join Date
    Jun 2005
    Posts
    178
    in order to use inside combustion air if it is allowed by the manufacturer is if you have enough sq footage in the furnace room unless the door has louvers but you still have to go up to 3 inch if the run is too long or has too many elbows or both it is usally 15 feet and about 4 elbows before you have to go bigger

  5. #18
    Join Date
    May 2004
    Location
    Rapid City, SD
    Posts
    7,403
    The down sides to not piping in the intake air...
    If there's chemicals in the area, they are sucked into the furnace and burned. This can cause premature heat exchanger wear.

    Also you are sucking air from the house and exhausting it. This is basically is blowing air you paid to heat outside. Also it can cause a slight negitive pressure in the house, which will cause more air to leak through the cracks around windows, doors, outlets etc.

    But if it is indeed only rated for 2 pipes, you'd best use 2 pipes so the warrenty isn't void and it'll pass code.

  6. #19
    Join Date
    Oct 2002
    Location
    Yo.... Here!, I'm right here..
    Posts
    6,236
    I just looked it up on line pages 16 thru 18 on the installation instructions spec the combustion air and area size, or duct size for tight area.

    This furnace Can be installed either way as stated before, but Bryant is pretty specific about combustion air from indoors

    We use the 2 pipe method for all 90%, and a Concentric Vent kit [ one sidewall or roof penetration ]

    been a Bryant dealer 25+yr

  7. #20
    Join Date
    Apr 2001
    Location
    san jose,ca.
    Posts
    5,285
    I not only have my reading glasses on i also have a magnifing glass in from of them,but as usual i`m no help .All i deal with is the 355MAV`S NOT THE AAV`S.I still say two pipe only.

  8. #21
    Join Date
    Oct 2002
    Location
    Yo.... Here!, I'm right here..
    Posts
    6,236
    Ok I'll repeat this furnace 355AAV is designed for either two pipe or 1 pipe and combustion air from inside the house. I wouldn't do it that way but it is in the install manual. I just downloaded them, from hvacpartners. The very first sentence in the manual says One pipe OR Two pipe

    [Edited by pjs on 10-31-2005 at 10:21 PM]

  9. #22
    Join Date
    Apr 2001
    Location
    san jose,ca.
    Posts
    5,285
    PJS,your the man..........Good job answereing his question
    & clarify=ing the difference for me, thanks...

  10. #23
    Join Date
    Jun 2005
    Posts
    40

    Talking Thanks everyone

    I appreciate the excellent responses. I think I'll pass on telling my father-in-law about the install issues. I don't want to get him overly concerned. And I surely don't want to get too piss at me. I plan on getting a real nice fishing boat when the wife get her cut of the inheritance. Wouldn't want to blow it now

  11. #24
    Join Date
    Jun 2005
    Posts
    178
    thats all good pjs but does it tell you how long and how many elbows you can have before going to 3 inch

  12. #25
    Join Date
    Oct 2002
    Location
    Yo.... Here!, I'm right here..
    Posts
    6,236
    Ah ulterior motive I like that, sounds as if he's getting a good job, I'd still use the 2 pipe though with a concentric vent kit. JMO even if it cost extra.

  13. #26
    Join Date
    Apr 2001
    Location
    san jose,ca.
    Posts
    5,285
    I would to, & he would have to look at the vent tables to determine vent size with respect to elevation, 90`s & length.The vent size starts at 1 1/2",2"2 1/2" & 3 ".....

Page 2 of 3 FirstFirst 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event