Results 1 to 6 of 6
  1. #1

    Over/under conversion to side by side question.

    I have a 20 year old Goettel 4 ton packaged unit I am replacing. I am thinking of going with the Lennox 15CHPXA-48-230 which is another 4 ton packaged unit. One of the reason for this device is the MERV 16 pleated filter that removes over 95% of particles down to 0.3 microns. Wife and kids have asthma and allergies I am hoping the filter helps with both. The other packaged units I looked at do not have the whole house type filter.

    The contractor will not install the 4 ton unit with out replacing the over/under and riser duct work with a side by side setup. He says a 4 ton unit is to big for the 90 degree elbow and will create to much back pressure causing premature compressor failure. So far I do not have a problem until he said the rigid riser would be replaced with flex duct. This is only a 3 to 4 foot run straight up to the roof unit. Is this something to be concered about or really no problem since the run is so short?

    Thanks for all of the great info here.
    Doug

  2. #2
    Join Date
    Sep 2002
    Location
    Boise Idaho
    Posts
    1,032
    converting from over under to side by side is always better then making a 1/2 crossover box. Are you in arizona or vegas? The couple feet of flex should be no prob if installed properly, and this def is a winter job. Any possibility of converting to a gas package unit over the heat pump?

    matt

  3. #3
    Join Date
    Feb 2007
    Location
    Las Vegas,NV
    Posts
    747
    I think it's good that the contractor wants to reconfigure your setup to side by side without a single changeover box. IMO that is the best way to do a professional changeout on your type of setup. Some of the older over/under units had a tiny elbow with the supply and return all crammed into one piece, and then along comes someone and shoves a big --- replacement unit up to it! I'm sure Matt being from Vegas has seen plenty of those!

  4. #4
    Thanks guys

    I'm in arizona and wanted to get this done before a failure in 110 degree heat. Gas is not an option only electric. I have 1 more cotracting coming out this afternoon and then a decision to make.

    Doug

  5. #5
    Join Date
    Feb 2007
    Location
    Las Vegas,NV
    Posts
    747
    IMO I would stick with a heat pump. I purposely took out my gas unit to have a heat pump, everyone thought I was nuts, but I have to say my house is much more comfortable from longer run times and the heat is not so hot and dry.

  6. #6
    Join Date
    Jul 2007
    Location
    Phoenix, AZ
    Posts
    206
    It sounds like the return air riser may be to small? Plus the 20 year old riser may have 20 years worth of dust and dirt in it. The flex duct would work fine.
    Just make sure the flex duct is sized right and the return air filter grille is the right size. Also some of the old 4 ton Goettl units were heavy duty. Meaning they had 48,000 to 54,000 btus of cooling. Check to see how many btu`s of cooling the new 4 ton unit has. Sometimes the new units come up short on btus of cooling. Then you have to up size the unit.

    If return duct is ok and right size then you could get rid of metal elbow on the roof and go with a down shot sheet metal fitting on the roof. Which means the supply air and return air leaves from underneath the new package equipment. The new equipment is now set up for this down flow which works great for the over and under duct work you have on the roof. Then there is no duct work to be changed in the attic.
    Hope this helps.
    mark

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