Results 1 to 9 of 9
  1. #1
    I'm in the process of choosing a company for my furnace and ductwork install. I live in SoCal, if that makes any difference. My one request I have of each representative is that I get to see an example of a residential installation that there company has done.

    I just got back from my first one, and I am very glad I took a look! This was the sister in law of the sales rep. She had at least one flex duct run that had popped of the plenum. The flex had very little to grip to on the takeoff, as it was just a crimped ended takeoff - no bump for the flex tie to wrap around. Another used an uninsulated metal elbow... and it appeared to be rusty for some reason.

    I know from my readings here that installation counts MORE than the actual equipment used. In this case there was something obvious I could point to.

    Next time I go up to look at an installation, I'll be able to see the furnace, the plenum box, the duct connected to the plenum, and maybe some short duct runs. Is there anything I can look for to help me identify a good install from a bad one?

    Thanks for any advice you can share!

  2. #2
    Don't the use real metal duct work in California?

    You wnt a good job than go with 26ga round runs off a square trunk.

    That blast flex duct has aomuch restiction in cmparison it's a wonder the y even work.

    I'm a shhet metal purist though, so I am sure the oppsoing point of view will make it self known.

  3. #3
    Around here, it's hard to find a home that has been run with solid duct.

  4. #4
    Join Date
    Oct 2005
    Posts
    88

    An opinion from the outside looking in

    I'm not sure how easy it is to judge an installer without watching the work done. The end result might look neat and shiny, but ... how did the installer choose that size furnace? Manual J? Rule of thumb? Is it even remotely the right size for the house? (Friend of mine had at least 2 contractors come in and insist on proposing a 100k furnace for a 30k house "because that's what the old one is, and you wouldn't want to go smaller.") Does the pretty looking vent conform in size and length to the venting tables? Is the temp rise and static pressure in range? Did the installer do the required operational tests and measurements on startup? (Have I ever seen a contractor do more than half of them? No, but some at least do that much ... I once watched a contractor hired by my landlord install a water heater, light it, and call it done without noticing the regulator was set for nat and an LP orifice was in the burner ... no, it was brand new equipment, probably rolled out of the factory on a Friday. I noticed something wrong when it took > 2 hrs to heat the tank. Glad it hadn't been mixed up the other way, it would have been a flamethrower.)

    Looking after the fact, you can only sort of see whether the work seems to have been done in the classic "neat and workmanlike manner" - and that does tell you something, but not nearly enough about how much thinking the installer put in while doing the work.

  5. #5
    xxpaulcpxx:

    I'm in Southern Cal too, and getting a new system. I've done a lot of research and have gotten several bids. I'd be happy to share with you my info about specific companies.

    The rules here don't permit posting my email address; can you suggest a way for us to compare notes?

    Thanks.

    Jacquelynn

  6. #6

    Wink

    My member ID here at aol dot com is where you will find me

    I've got HVAC Calc and I think it mentioned a 1 ton unit for my 1700sq house (no AC). The duct sizes they were mentioning matched what the calc figured. I'm getting a two stage variable speed unit, don't know which brand yet.

    The cheap quote speced an Amana AMV80905CXA, the expensive one speced a Carrier 58cvx09116. I don't know about the specific size, but it looks like the correct units for my needs.

    I do intend on watching the work as it is done, and what you mentioned are good things to look for. I was hoping there might be other obvious thing to look for other than a duct popped off the plenum!

  7. #7
    Join Date
    Jun 2005
    Location
    SW Wisconsin
    Posts
    5,031
    First, your home should be energy conservation audited and improvements made, "before any equipment system sizing."

    Then, reduce equipmenmt sizing as much as possible.
    There is always proper sizing and sealing of the duct system.
    Ask them to show you how they use Manual D to size the duct system.

    Here is some rough outline charting to provide a rouigh guide for duct and return air filter box grille(s) sizing.

    http://www.udarrell.com/proper_cfm_b...g_systems.html

  8. #8
    Thanks for the links. One thing I'm having trouble with is figuring out how much CFM and the tonnage of the system - no AC BTW. One has me at 4 tons the other at 5 tons. HVAC Calc said 1 ton... but let me pick the CFM, as if I had any idea what that should be!

    Maybe I'll get a better idea reading some of your links.

  9. #9
    Join Date
    Sep 2003
    Posts
    1,311
    Post the loads from Manual J and that will give a basis for the CFM.

    In addition to the others, here's one thing to look for: All of the runs (laterals) the same size; If they did/do that then they aren't doing Manual D.

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