Page 1 of 2 12 LastLast
Results 1 to 13 of 18
  1. #1

    60,000 BTU for 2,000 sq ft?

    I have a Carrier Weathermaker 9300TS 58MTA (93% eff.) 60,000 btu input furnace. The house is in MN and is 2,000 sq. ft.

    I recently bought this house. For some reason, the previous owner did not put any vents in the downstairs family room (there is a baseboard electric heater in there instead...wow, is that expensive to run). I am wondering if this furnace is just too small to handle that space or not, because I want to add vents down there.

    I realize there are many factors in sizing a furnace, but on the face of it this furnace seems much too small for this house in this climate. The house was built in the 70s and is not tight.

    So, I'm trying to figure out if it is worth trying to add vents/improve insulation with this furnace or if I really just need a larger furnace. Any advice?

    Thanks

  2. #2
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,331
    Previous owner probably didn't use that room as often as you do.

    Its probably large enough, if you have it zoned.

    If you just get a bigger furnace, then you will need to make lots of alterations to your duct work.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  3. #3
    Join Date
    Dec 2010
    Location
    The Quad-Cities area (midwest).
    Posts
    2,739
    Quote Originally Posted by jjack100 View Post
    I have a Carrier Weathermaker 9300TS 58MTA (93% eff.) 60,000 btu input furnace. The house is in MN and is 2,000 sq. ft.

    I recently bought this house. For some reason, the previous owner did not put any vents in the downstairs family room (there is a baseboard electric heater in there instead...wow, is that expensive to run). I am wondering if this furnace is just too small to handle that space or not, because I want to add vents down there.

    I realize there are many factors in sizing a furnace, but on the face of it this furnace seems much too small for this house in this climate. The house was built in the 70s and is not tight.

    So, I'm trying to figure out if it is worth trying to add vents/improve insulation with this furnace or if I really just need a larger furnace. Any advice?

    Thanks
    I always tell my customers to add the ductwork as needed for the addition or basement and "see" how it goes. Remember that you'll have the back-up heat (elec.) when it really gets cold.

    If a larger furnace is needed, you can do that at a later time or zone as B. T. said. At least let the contractor know your intentions. If room allows, he can run a seperate ductline to manually or auto zoning in the future.

  4. #4
    Join Date
    Sep 2002
    Location
    I don't know
    Posts
    2,905
    60k is not out of line at all.

    If it can't keep up, do everything you can to reduce heat loss.

    A room by room load calc may be required to fix the duct system - adding a couple of vents won't cut it.
    General public's attitude towards our energy predicament: "I reject the reality of finite resource depletion and substitute it with my own; energy is infinite, we just need an alternative storage medium to run the cars on. The economy can grow indefinitely - we just need to "green" everything! Technology is energy! Peak what?"

  5. #5
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,378
    60k is a LOT of heat. Think qty 12 of those 115V plug in heaters..

  6. #6
    Join Date
    Jan 2008
    Posts
    2,060
    Over-sizing gas furnaces never ceases to amaze me.
    I've seen 125K/80% units on 800 sq ft homes.
    I truly enjoy it when I see 40K units keeping customers warm, and comfy.
    And we're in a cold climate.
    After having enjoyed the comfort of a properly sized furnace, I could not imagine the agony of getting blasted by an over sized unit.
    Don't over size if your guy says 60K will do it.
    Get it in writing, and hold him to it if it doesn't work.
    Keep in mind, on the coldest days, it will run constantly to maintain, and may not be able to recover from a set back for hours.
    "Hey Lama, hey, how about a little something, you know, for the effort." And he says, "there won't be any money, but when you die, on your deathbed, you will receive total consciousness." So I got that goin' for me, which is nice. - Carl Spackler

  7. #7
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,378
    Quote Originally Posted by 2old2rock View Post
    Over-sizing gas furnaces never ceases to amaze me.
    I've seen 125K/80% units on 800 sq ft homes.
    I truly enjoy it when I see 40K units keeping customers warm, and comfy.
    And we're in a cold climate.
    After having enjoyed the comfort of a properly sized furnace, I could not imagine the agony of getting blasted by an over sized unit.
    Don't over size if your guy says 60K will do it.
    Get it in writing, and hold him to it if it doesn't work.
    Keep in mind, on the coldest days, it will run constantly to maintain, and may not be able to recover from a set back for hours.
    Come to think of it I've never lived in a house where a gas furnace WASN'T oversized... I guess high BTU furnaces don't cost much more to buy than correctly sized.

  8. #8

    60,000 BTU for 2,000 sq ft

    I have a Carrier Weathermaker 9300TS 58MTA (93% eff.) 60,000 btu input furnace. The house is in MN and is 2,000 sq. ft.
    _________________

    I'm a novice looking the same problem with the exact same 9300TS Carrier furnace in southern MI, considering whether the 60K BTUs will support an addition that will bring total to ~1900 sq. ft.

    These guys sayLinks to direct purchase sites are not permitted.
    45 BTUs per square foot (zone 4=S. MI) 50 BTUs per square foot (zone 5=MN)

    2000 sq ft * 50/sq ft = 100,000 BTU

    Are they just trying to sell a bigger furnace or is 60,000 BTU really enough for 2000 sq ft in MN/MI? From previous posts sounds like you can definitely get by with less -- are these BTU/sq ft recommendations blowing hot air?

    Thanks
    Last edited by beenthere; 07-13-2011 at 09:06 PM. Reason: emoved link to direct purchase site

  9. #9
    Join Date
    Mar 2008
    Location
    Atlanta, GA
    Posts
    149
    You would need to do a heat load calculation to determine what size furnace you would need. Because every house is different, sizing by square footage is a very easy way to get a furnace that is either too big or too small.

  10. #10
    Join Date
    Jun 2009
    Location
    Albuquerque NM
    Posts
    2,485
    Considering the cost of ductwork, it might be worthwhile to compare that with the cost of a minisplit heat pump for that room, if it's a large room. At least it's something to check into.

  11. #11
    Join Date
    Dec 2002
    Location
    Rochester, MN
    Posts
    5,305
    You have enough heat for that home. I have a1968 1,500 sq ft home in MN, and with our cold -20˚ cold snap, it had no issue keeping the house warm.

    Also basement don't need much to keep warm since it's in the ground.

  12. #12
    I would go ahead and add vents down there. If the furnace is undersized then, close the vents. That simple.

  13. #13
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,323

    Hmm REALLY ?

    Quote Originally Posted by johnny_five View Post
    45 BTUs per square foot (zone 4=S. MI) 50 BTUs per square foot (zone 5=MN)

    Are they just trying to sell a bigger furnace or is 60,000 BTU really enough for 2000 sq ft in MN/MI? From previous posts sounds like you can definitely get by with less -- are these BTU/sq ft recommendations blowing hot air?
    That the rule from year 1891.

    .. Two centuries have passed. So divide by 2.
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

Page 1 of 2 12 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