Page 2 of 2 FirstFirst 12
Results 14 to 22 of 22
  1. #14
    Gas is not available. There are electric baseboard heaters now.

  2. #15
    The downstairs has no returns currently. None of the bathrooms have supply's currently. I may add 2 more supply's not sure yet.

  3. #16
    Join Date
    Aug 2012
    Location
    North Dakota
    Posts
    518
    so theres ele. b.b. and a trunked a\c system ? how about a propane furnace it still will beat all electric $$$$

  4. #17
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,295
    Quote Originally Posted by racinkart2 View Post
    Most HVAC companies recommend a 3 ton heat pump for my house. If I went to a 4 ton unit - does the winter temperature of the balance point lower (any idea on by how much it will lower, 2000sqft house in PA)? I know my AC will short cycle - I do not care about this, I'm looking for the most efficiency in the winter months as heat is on for more months than AC. The unit will be a dual stage Trane XL18I. Are there any other drawbacks of over-sizing a heat pump? Thanks.
    What are your electric bills for the last 24 months?
    Balance point is normally about 32'F (9 HSPF) , Carrier GREENSPEED ( upto 13 HSPF) might be as low as 10'F.
    http://www.docs.hvacpartners.com/idc...825-071-25.pdf
    Last edited by dan sw fl; 08-01-2013 at 01:19 PM.
    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

  5. #18
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,295
    Assuming your heat loss is 45,000 BTU/HR at 5'F (about normal for 2,000 sq feet), the CARRIER GREENSPEED 4-TON Balance Point is 10'F.
    .................................................. .................................................. ...............________ .._________ 3-TON Balance Point is 25'F.
    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

  6. #19
    I just purchased the house so I don't have past electric bills. Sorry.

  7. #20
    Any other comments with 3ton unit versus 4ton unit?
    Thanks everyone.

  8. #21
    At 17 degree's, it looks like I'd get roughly 7500 BTUH more with 4ton versus 3ton unit. In your opinion, which one do you think you'd go with? My thinking process is that in the summer the unit will run at 60% capacity much longer than at 100%, in the winter the unit will run at 100% more often and have to defrost less. I admit, I only know the basics about HVAC. (60% of 4ton is 2.4 ton - which should be sufficient for most days in the summer).

  9. #22
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,295
    Quote Originally Posted by racinkart2 View Post
    All the duct work will be updated to R8. There will be 1 additional return added and 1 supply added for the larger unit. When I look at the AHRI certificates, the 3 ton unit is rated at 22,200BTUH @ 17 degree's F, the 4 ton unit is rated at 29,800BTUH @ 17 degree's F, both for region IV. Do you think the 7600 extra BTU from the 4 ton justifies going with the larger unit?
    Example
    Balance point might be reduced from 27F to 19F.

    Outside
    ___ Heat Loss ________ 4-ton ________ 3-ton
    70 0 xxxxxx________- ________-
    65 2,857 ________- ________-
    60 5,714 ________- ________-
    55 8,571 ________- ________-
    50 11,429 ________- 47,000 ________- 35,000
    45 14,286 ________- 44,167 ________- 32,917
    40 17,143 ________- 41,333 ________- 30,833
    35 20,000 ________- 38,500 ________- 28,750
    30 22,857 ________- 35,667 ________- 26,667
    25 25,714 ________- 32,833 ________- 24,583
    20 28,571 ________- 30,000 ________- 22,500
    15 31,429 ________- 27,167 ________- 20,417
    10 34,286 ________- 24,333 ________- 18,333
    5 37,143 ________- 21,500 ________- 16,250
    0 40,000 ________- ________-
    __ Heat Loss _______ 4-ton __________ 3-ton

    Defrost operation is another story.
    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 2 of 2 FirstFirst 12

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