Results 1 to 6 of 6
  1. #1
    Join Date
    Jan 2008
    Location
    Lehighton, Pa.
    Posts
    178

    Vent temp. variances in different rooms

    New home with hp and propane back-up. While in gas mode I measured vent output temps using an infrared gun. Some vents read 110 deg. while others read 95. In addition in room above garage, the vent closest to the main structure as well as furnace reads 108 and the vent furthest away reads 94.

    Are thes variances acceptable, or should they all be somewhat consistant?

  2. #2
    Join Date
    Aug 2012
    Location
    North Dakota
    Posts
    518
    the duct may run through an unconditioned space thus creating a loss of temp. though those stated are fairly large and should be addressed

  3. #3
    Join Date
    May 2008
    Location
    Missouri
    Posts
    3,504
    How does the house heat room to room? What kind of air filter do you have and how long has it been since replaced/cleaned? If you have a 1" pleated (accordian type) filter, throw it away and go back with the plain 1" fiberglass filter as the restrictive pleated will cause heating and cooling problems!!

  4. #4
    Join Date
    Jan 2008
    Location
    Lehighton, Pa.
    Posts
    178
    While the furnace is in a conditioned area, all ductwork is through the attic and down mostly exterior walls.

    The main floor is one zone, and the room above the garage is another. Stat on main floor is set to 72. All rooms are within 1/2 -2 deg. of stat reading. The second zone is set to 68 and that is what the actual temp. is.

    The air filter is the 4 inch pleated carrier filter per mfgs. recommendation. Filter is clean.

  5. #5
    Join Date
    Sep 2009
    Location
    Arnold mo
    Posts
    3,964
    IR gun only measures surface temps, not air. A better way would be to use a temp probe into air stream after furnace has run for several minutes. If all of the rooms are pretty close to same temp, what is your concern?
    An answer without a question is meaningless.
    Information without understanding is useless.
    You can lead a horse to water............
    http://www.mohomeenergyaudits.com

  6. #6
    Join Date
    Aug 2009
    Location
    Prattville, Alabama
    Posts
    2,036
    Also, with IR gun the "emissity" (?) of the material you aim it at matters. I've aimed mine at copper hot water pipe that is painted in some areas. It will read 160 F on the paint, and 1 inch away on bare copper it will read up to 50 F cooler. Plus aiming it at a grille, you are likely reading the surface temp of what is past, or behind, the grille. Such as surface temp of the duct insulation, made of different material with different emissity. It will average the temp reading of all that falls in the "sensed area". Tipsrfine is right, use the proper tool.

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