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  1. #14
    Join Date
    Apr 2004
    Posts
    7,680
    Better look at it when its cooler but I really suspect he stuck a 3 ton unit on 2 tons of ductwork and his lack of airflow which is apparently tolerable in cooling is now comming back to bite him in the butt. I am not sure, without looking but I dont think a 50,000 furnace even has the drive for 3 tons, especially against restricted ductwork.

    Now, I'm betting because of low airflow, he has compensated by overcharging the unit. That might explain the HPS trip in heating. But that can be fixed by adjusting the charge seasonally. Add a little in summer and take a little out in winter. Of course defrost will not work well but hey, the cake and eating it too thing comes to mind. Then again you got gas back up.

  2. #15

    Another Update

    This will probably be amusing to some...

    Another tech visited Friday. Ran some tests, furrowed brow, went straight to the coil and air handler. Wrote down some numbers. Went out to his truck, was on the phone for 15 minutes. Comes back and tells me there's no way this 3-ton heat pump and coil will work correctly with my existing 2-ton furnace. Disconnects the h/p and instructs me not to use it until this is resolved.

    Now I should point out that the installers have been very polite and professional, and they're not trying to blow smoke. They get assigned a job, job says "Install this equipment", they install it. It's not their fault if it's the WRONG equipment. I guess.

    Within an hour I get a call from the service manager. Again, very polite, no BS, "We screwed this up. You now have 2 options: 1) We remove the 3 ton unit and replace it with a 2-ton, as per original; or 2) We upgrade the furnace to a 3-ton, which we will do at our cost for a Lennox furnace plus the labor to install it."

    So now I'm wondering if my ductwork can handle a 3-ton. I don't want whistling ducts or a hurricane blowing through the house. Maybe the correct solution is a 2.5 ton system. I dunno. I still feel strongly that the original 2 ton system was undersized for the house, given the volume of air due to high vaulted ceilings.

    Ideas welcome.

    Oh, and is there any such thing as a special low-restrictor grill for the return, of which I only have 1? This is a downdraft system if it makes any difference, with the return mounted high on one of the ceiling vaults.

    EDIT: And if we're going to start over, I'm almost tempted to just clean out the bank account by going Lennox all the way, rather than a mixed Goodman and something else, be it Lennox or the original Day & Night.

    [Edited by typical homeowner on 07-10-2005 at 08:17 PM]

  3. #16
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,517
    i would say you contractor did right by you and steped up to the plate and admitted thier misstake. they gave you two offers to rectify thier misstake at thier own expense witch is what they should do except labor on the upgraded furnace. labor only to you. sounds like thier being fair to you and very honest. you question the duct and the size of the original system. ok now it is time for you to step up and ask the contractor to resize the duct and have the system done right once and for all. you have the options and either way is is your call. yes it the ductwork was sized right for 2 tons of air 3 tons of air will be louder

  4. #17
    Join Date
    May 2004
    Posts
    12,290
    Originally posted by tinknocker service tech
    i would say you contractor did right by you and steped up to the plate and admitted thier misstake. they gave you two offers to rectify thier misstake at thier own expense witch is what they should do except labor on the upgraded furnace. labor only to you. sounds like thier being fair to you and very honest. you question the duct and the size of the original system. ok now it is time for you to step up and ask the contractor to resize the duct and have the system done right once and for all. you have the options and either way is is your call. yes it the ductwork was sized right for 2 tons of air 3 tons of air will be louder
    Agreed, good note

  5. #18
    I agree. So far they've been very good about it and they're offering to make it right. I'll come back with more info when I get it. Hopefully we'll decide on a course of action Monday.

  6. #19
    Join Date
    Sep 2001
    Location
    Vancouver Canada
    Posts
    996
    See what happens when guys don't check things out completly. Should never have been installed on that furnace. Did your old system ever work correctly? or was it not cool enough right from the start? If at some point in the past it stopped cooling enough then I would say 3 tons is too big for the house. Be interesting to see what the install company has to say about the ductwork.
    "Go big or Go Home"

  7. #20
    The official reason given for this error is the estimator screwed up when he was looking at the old system. He ID'd the old furnace as a 3-ton. It didn't help that the model number was smudged on the label on the furnace. He made some calls and they decided from what they could read of the model number, and the 1/3 horsepower rating on the blower motor, that it had to be 3-ton. Turned out to be wrong.

  8. #21
    Join Date
    Apr 2004
    Posts
    7,680
    I'm still a little bothered by the 2 and 3 ton thing.

    He offered to remove it and install a 2 ton. My question is, what is the load? Is it 2 or 3? If its 3, the 2 ton will not work. If the old 2 ton did, maybe it will. I'd need to see a load calc.

    You could take the furnace for free. Then pay him to upgrade your duct system if you really need the 3 tons. Remember gas furnaces will typicly offer larger motors that just the air handlers but thats to overcome the HX. You might just have some air noise issues.

  9. #22
    I'm more than a little bothered by the 2 ton 3 ton thing too.

    I just talked to the svc mgr again. He's gonna run some numbers for me to change everything to 2.5 ton, including running some additional ductwork to the far end of the house. I dunno, this sounds like what should have been done in the first place.

  10. #23
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,517
    read my first post before this gets out of hand
    yes maybe this should have been done first but as stated they messed up. you questioned this duct work about being sized for three ton. now they are doing the right thing and sizing the duct for three tons of air.if you need 2.5 tons of cooling then you are going to get a three to drive furnace. for it to work properly and queitly the duct will ned to be modified. it does not matter what brand you are getting as far as i am concerned because they are all the same. now as i have said do it right once and for all.
    good luck with your new system it should give many years of good service. i think you found a good contractor

  11. #24
    Join Date
    Jan 2005
    Posts
    340
    Originally posted by typical homeowner
    I dunno, this sounds like what should have been done in the first place.
    What should have been done in the first place is a LOAD CALCULATION. That will tell you what size system you need. 2 T, 2.5 T, 3 T ?? or smaller / larger?

    http://www.proctoreng.com/articles/bigger.html

    Ask your contractor (who I think is standing tall on this one) to run a "Manual J" so that you all don't have to keep on speculating on what size this system should be.

  12. #25
    Join Date
    Nov 2002
    Posts
    230
    And to think, all this money could have been spent on trees and or porch awnings.

  13. #26
    "And to think, all this money could have been spent on trees and or porch awnings."

    The original system was undersized and no longer working correctly. The house sits on a sloped lot, slopes down from the street. It's a single-level house, but the back [west] side is basically at what would be the 2nd floor level due to the slope. The backyard is also shallow, and the house very high, so it would take a few hella-big trees to do any good and they would dominate the yard. Awnings are not wanted (though the windows have sunshades on them in the summer).

    Maybe someone can riddle me this: If I keep the 3-ton heat pump and coil, and install a new high-end 94%-efficiency variable-speed furnace (Lennox G61MPV-090), and if it wants to run at low or medium speed, how is that gonna solve the problem of moving sufficient air across the coil? Seems like it would have to run at high speed to satisfy what the heat pump wants.

    I'm confused.

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