Page 2 of 3 FirstFirst 123 LastLast
Results 14 to 26 of 35
  1. #14
    Join Date
    Sep 2012
    Posts
    373
    Quote Originally Posted by 54regcab View Post
    45,000 should be plenty, doubt the 2nd stage will ever kick on.
    Does it 'feel' hot when it short cycles?
    Not really, well sometimes. It's kinda hard to explain. There has been some times when I bumped up the temperature a few degrees and the furnace was able to stay on for 7 minutes to allow high stage to kick in. After that it really feels warm.

  2. #15
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,875
    turn the fan to on and see if it evens out the temps
    We really need change now

  3. #16
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,505
    Quote Originally Posted by 545GAlady View Post
    Not really, well sometimes. It's kinda hard to explain. There has been some times when I bumped up the temperature a few degrees and the furnace was able to stay on for 7 minutes to allow high stage to kick in. After that it really feels warm.
    If the house was vacant for an extended period and you wanted a quick warm up the 2nd stage could be useful. For keeping a constant temperature I doubt he 2nd stage would ever be used. Looks like they sized the furnace based on 1st stage capacity with 2nd stage as "reserve/recovery". How much total sqft for the upstairs? Does it feel like it gets hot/cold during normal cycling?

    Cycle time is a comfort vs. efficiency game. Setting the thermostat for longer cycles give larger temperature swings which if excessive result in poor comfort. Shorter cycles reduce efficiency and add wear and tear to the unit. Striking a balance is the key. Oversized equipment will make it difficult, undersized equipment won't keep up on the coldest/hottest days. The idea of 2 stage is size it so that the unit won't be able to keep up on 1st stage once temps start getting close to outdoor design temperature.

  4. #17
    Join Date
    Sep 2012
    Posts
    373
    catmanacman and 54regcab thanks for the input. The furnace that was installed according to Lennox's website is the smallest capacity SL280v it comes in. The upstairs does get warm during normal cycle, but it takes about 10 to 15 minutes for the temp to cool down. The total sq ft is 1400 sq ft.

  5. #18
    Join Date
    Sep 2012
    Posts
    373
    Just in case this helps, here's the model number of the furnace.Name:  002.jpg
Views: 43
Size:  38.7 KB
    I meant to say 43,000 BTU, not 45,000 BTU in one of my previous posts.

  6. #19
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,505
    Low BTU furnaces with variable speed blowers have always been difficult to find. The only manufacturer I know of who makes a furnace under 50K high stage with a variable speed blower is Rheem/Ruud. Would like to see more of them, especially for southern climates. The higher capacity variable speed blowers are great for cooling, but the minimum size heat is large enough for winter. For sizing I think the installer did the best he could within the choices of his lineup. In moderate heating climates I question even installing a gas furnace for the upstairs. Depending on your layout and energy costs a heat pump may have been a better choice. Lower BTU, cooler delivered air. Longer cycles, better comfort.

    However what you have is what you have, you will have to decide how long you want your cycles to be (comfort vs. efficiency) and have the thermostat programmed accordingly.

  7. #20
    Join Date
    Sep 2012
    Posts
    373
    I'm pretty sure that our AC was size properly, but sometimes it short cycles as well. Sometimes the air coming out of the vents is not very cold unlike our main level system which blows out ice cubes.

    The tech who serviced our furnaces said that he does not like Rheem/Ruud that much, but of course that's his own opinion.

    I do wish that we did ask for a quote for a heat pump, because that is what we have for our basement system and our main level system (main level system is dual fuel). We always have our thermostats running on a program.

  8. #21
    Join Date
    Sep 2012
    Posts
    373
    Our local HVAC company is a Lennox and Amana dealer and they are the same ones who installed our new AC unit. We were quoted on the GMVC8 furnace and I know that pricing is not allowed here but all I'm gonna say is that it was the same price as the Lennox, but we went with the Lennox because of quietness.

    I would probably be in it for the efficiency because it won't put much wear and tear on the unit. But then comfort will be the issue.

  9. #22
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,505
    If you would have done DF upstairs I doubt the gas would have ever kicked on. If the gas isn't going to kick on there wouldn't be much point in having the furnace at all. Electric strips would have been fine for the rare times the HP couldn't handle the load.

    Rheem/Ruud is fine by me, it's what I have in my own home (actually is Thermalzone, which is made by Rheem/Ruud). Wanted something better than the builder grade, but didn't want to spend a lot more. For us, spending the extra $$$ for the Lennox/Trane/other top brands wasn't worth it. Price to performance with Thermalzone met our needs. Being in the business I was looking for certain internal construction features, and I could care less about the label on the outside of the box.

    Good choice going for the Lennox over the GMVC8, especially at the same price point. IMHO the Lennox is a much better built unit.

  10. #23
    Join Date
    Sep 2012
    Posts
    373
    Quote Originally Posted by 54regcab View Post
    If you would have done DF upstairs I doubt the gas would have ever kicked on. If the gas isn't going to kick on there wouldn't be much point in having the furnace at all. Electric strips would have been fine for the rare times the HP couldn't handle the load.

    Rheem/Ruud is fine by me, it's what I have in my own home (actually is Thermalzone, which is made by Rheem/Ruud). Wanted something better than the builder grade, but didn't want to spend a lot more. For us, spending the extra $$$ for the Lennox/Trane/other top brands wasn't worth it. Price to performance with Thermalzone met our needs. Being in the business I was looking for certain internal construction features, and I could care less about the label on the outside of the box.

    Good choice going for the Lennox over the GMVC8, especially at the same price point. IMHO the Lennox is a much better built unit.
    Thanks for the info. So obviously going with a heat pump would have been probably a better idea.

    We had Rheem at our old house and the units worked fine as far as I can remember. Of course any brand will work properly as long as it's installed and sized properly.

    I do agree that the Lennox is a better built unit than the Goodman and you can just tell by looking at both units.

    We are having our basement system inspected this upcoming Tuesday and I will ask the tech about the upstairs system and see if a heat pump will be more ideal. Thanks for all of the advice.

  11. #24
    Join Date
    Sep 2012
    Posts
    373
    I was also wondering if the size of the supplies and returns could be the effect. I doubt this would be the cause but I don't really know. Could this be?

  12. #25
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,505
    If ductwork is wrong it can cause all kinds of problems.

  13. #26
    Join Date
    Sep 2012
    Posts
    373
    Quote Originally Posted by 54regcab View Post
    If ductwork is wrong it can cause all kinds of problems.
    There's one supply in each bedroom and they are all 8 inch. Same with the size of the returns in the bedrooms.

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