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

Thread: 75k or 90k?

  1. #1
    Join Date
    Aug 2011
    Posts
    12

    75k or 90k?

    Got a couple of guys who are recommending the following.

    - Lennox 95%, 88k BTU
    - Bryant 95%, 80k BTU

    I'm wanted to pick up a Rheem furnace as I like the pricing where I'm looking, however the 95% efficient ones only come in 75k and 90k BTU. Any thoughts on which would be the better to go with?

  2. #2
    Join Date
    Feb 2004
    Location
    chicago suburbs
    Posts
    4,422

    get the right size

    how would we know what size you need?..what size should i get for my house?..what about my neighbor?... his house is nice.
    FILL OUT YOUR PROFILE!!

  3. #3
    Join Date
    Apr 2004
    Location
    MN
    Posts
    1,800
    Have a load calc performed and get the size that will meet the requirements of your house. Thats the best we can do for you.
    A Veteran is a person, who at some point in their life, wrote a blank check payable to the United States of America for payment up to and including their life.
    Gene Castagnetti-Director of the National Memorial Cemetery of the Pacific in Hawaii

  4. #4
    Join Date
    Aug 2011
    Posts
    12
    Sorry if I was not clear enough. The home is a very unique. In total it's about 3600sq ft, with the front and back portions of the home being heated by seperate furnaces. The front portion of the home comes in around 2000sq ft and the load calc is giving a recommendation of 82k. I wanted to go with Rheem however the models stradle the 80k range with only a 75k unit and a 90k.

    Figure I def don't want to overcompensate and feel the 75k would be the way to go.

  5. #5
    Join Date
    Apr 2004
    Location
    MN
    Posts
    1,800
    If the load calc was performed properly, it won't lie. Have your contractors quote you a 2 stage furnace.
    A Veteran is a person, who at some point in their life, wrote a blank check payable to the United States of America for payment up to and including their life.
    Gene Castagnetti-Director of the National Memorial Cemetery of the Pacific in Hawaii

  6. #6
    Join Date
    Feb 2009
    Location
    Portland OR
    Posts
    1,951
    Where do you live to get a 82K BTU heat load on only half the house? I have a feeling those numbers are doctored more than a little bit. I would probably go with the 75K BTU furnace but MAKE SURE THE AIRFLOW MATCHES. People to often size their furnace on their heating load and forget that furnaces have a 3 ton, 4 ton or 5 ton blower and that needs to be sufficient and match up with the air conditioner/heat pump if you have one.
    Check out my YouTube channel - http://www.youtube.com/user/skyheating1 We have customer testimonials, product reviews and more!
    Like us on FACEBOOK if you like our advice here!

  7. #7
    Join Date
    Aug 2011
    Posts
    12
    We live in Minneapolis, so as you could imagine, butt cold. Interestingly enough, the current furnace we'd be replacing is a 31 year old Lennox. Input on that is 3ton & 82,000 and I'm guessing 60% efficiency. From my math that's about 50k output. So I find it interesting that I've been quoted with an 82k and a 88k @ 95% efficiency.

  8. #8
    Join Date
    Feb 2009
    Location
    Portland OR
    Posts
    1,951
    Quote Originally Posted by numb3r View Post
    We live in Minneapolis, so as you could imagine, butt cold. Interestingly enough, the current furnace we'd be replacing is a 31 year old Lennox. Input on that is 3ton & 82,000 and I'm guessing 60% efficiency. From my math that's about 50k output. So I find it interesting that I've been quoted with an 82k and a 88k @ 95% efficiency.
    Me too... if I were to guess and take a shot in the dark I would say you would be fine with a 75K BTU. But this is without any additional knowledge and is a pure guess. Get another quote or use the HVAC-Talk.com contractor locator map.
    Check out my YouTube channel - http://www.youtube.com/user/skyheating1 We have customer testimonials, product reviews and more!
    Like us on FACEBOOK if you like our advice here!

  9. #9
    Join Date
    Aug 2011
    Posts
    12
    Ok, I'll do a bit more snooping and see what I come up with. Will let you know.

  10. #10
    Join Date
    Jan 2008
    Posts
    1,970
    Chances are you are over sizing. But we really don't know. There is only one way to be sure. Have a load calculation done.
    Problem is that many contractors will over size anyway because you're in a cold climate, just to cover their arse.
    "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

  11. #11
    Join Date
    Aug 2011
    Posts
    12
    Correct me if I'm wrong, but going off the size of the current 30 year old furnace (output of around 50k) - if I purchase this Rheem 75kb multistage, I may find out that it would run at low fire the majority of the time. Would you rather have a multistage running at low fire compared to high most of the time?
    Last edited by Dad; 08-31-2011 at 08:38 PM.

  12. #12
    Join Date
    Feb 2004
    Location
    chicago suburbs
    Posts
    4,422
    ur done.
    FILL OUT YOUR PROFILE!!

  13. #13
    Join Date
    Aug 2011
    Posts
    12
    And you've been super helpful Tinner. Thank you so much.

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