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  1. #1
    Join Date
    Jul 2008
    Posts
    4

    Need Advice- Oversized System & Bad Installation

    I would greatly appreciate any advice from the forum on this. I bought a 2,800 sq ft house that was gutted, remodeled, and had an addition that doubled the house size (single story ranch). All new sheet rock, ceilings, insulation, windows, siding, plumbing, electrical, roof, and HVAC system. The builder used an HVAC contractor that never did a Manual J calc, and installed two 3-ton Goodman 16 Seer heat pump split systems with the condensers right next to the master bedroom window. I've been in the house for four months, now in middle of the hot South Carolina summer. I hired a third party, qualified HVAC contractor to give me a detailed report of the many installation deficiencies (too ugly and numerous to list) and he told me that the system is way oversized for the house.

    I bought HVAC-Calc and ran the Manual J calcs myself with great care. As an engineer and competent software user, I am confident that the software is giving me accurate results. Using this, HVAC-Calc specifies a 2.5 ton system for the Living Space zone, and a 1.5 ton system for the Bedroom zone (with conservative inputs for the infiltration, insulation, shading, windows, etc). The contractor installed a 3 ton system for the Living Space zone and another 3 ton system for the Bedroom zone. The BR zone system is double what it needs to be.

    I'm aware of the problems with having an oversized system, but the sad fact is that it is so common for HVAC contractors to oversize systems - how much of a case do I need to show negligence in order to force my builder to correct the problem and replace the system with the right sized units? When I told my builder and another Goodman contractor about the problems their first response was "it should be the right size units according to your home's square footage and using a rule of 1 ton per 500 sq ft."

    I would appreciate any helpful advice. Thanks in advance!

  2. #2
    Join Date
    Jul 2008
    Location
    Kansas
    Posts
    61
    Quote Originally Posted by rb282 View Post
    When I told my builder and another Goodman contractor about the problems their first response was "it should be the right size units according to your home's square footage and using a rule of 1 ton per 500 sq ft."
    Dun dun dun.

    I shudder when I think of what other problems and spotty construction practices are scattered around your house. Seems to me "remodeled" more often than not usually means "we covered up everything bad with lots of paint and thick knock-down texture."

    I'm not really familiar with how you go back after builders for this kind of thing. But was there ever an agreement or contact outlining what you were getting? That would be a place to start. Otherwise, if you just bought the place "as-is" I doubt there is much you can do. Sounds like you've found one decent contractor though. Good luck. =\

  3. #3
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,449
    Get what you can out of the builder. After you exhaust that, Adding a whole house dehumidifier will control the indoor humidity regardless the size of the a/c. I have done that many times. All a/cs end-up over-sized during low/no cooling load. If you getting adequate fresh air during the low cooling conditions, all homes end up humid after a week. Adding 50-90 lbs./day of supplemental dehumidification keeps the entire home <50%RH. Most homes need 50-75 cfm of fresh air to purge indoor pollutants. During the winter the stack effect added to wind provides this fresh air. During the summer no stack effect and winds are intermitant. Regards TB
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

  4. #4
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,112
    Take some humudity readings and record them.
    Then have your lawyer send the builder a letter with a copy of the load calc, and your humidity readings.
    Your lawyer will know how to word it.
    You'll get a better response then.
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    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  5. #5

    Lawyers are a lot more expensive than HVAC guys

    My rule is never sue anyone if its less than $10,000.
    I've eaten some bad stuff from contractors, but I'm convinced
    that's the smart thing to do.

    I'm sure you can have a smaller unit put in your bedroom
    area for a lot less than $10,000.

    I think you have a particularly hard case to make that the unit
    is oversized. Now if it was dangerous that might be another
    story. I've had dangerous.

    If this is the only issue you have I'd suggest forget sueing.

    However if you just discovered the whole house is built on
    quicksand and is going to subside its another story.

    Don't feed the lawyers!

    If you are really mad at the contractor you could threaten him
    with some bad publicity. I've had some success with this route.

  6. #6
    I think Teddy Bear nailed this issue. The biggest problem from oversizing results in high humidity leading to mold and other health related issues. Take the $10,000 lawyer money and get a good contractor to install a whole house dehumidifier and feed yourself instead of the lawyer.

  7. #7
    Join Date
    Dec 2007
    Location
    Cedar Grove, Wi-Sheboygan
    Posts
    1,582
    Here's is one suggestion you may want to entertain, Send a nice little letter to the orginal contractor stating your postion and with facts as TB suggested with taking RH readings to back your claim and ask the orginal contractor to give you the numbers of the manual J he used to size your equipment and then compare, if he didn't use manual J but used the "Rule of Thumb" to size your equipment then based on his menthod and your facts and load calc results are apples & organges then you have a case and at that point I would proceed to have him either replace what he installed with the proper size equipment or call another contractor to replace with proper size equipment and then file suit against the orginal contractor. Oh and you should not need to lawyer up if you have your facts and proof that he never properly sized the equipment in a civil matter or small claims.

  8. #8
    Join Date
    Mar 2008
    Location
    Jackson, NJ
    Posts
    176
    Quote Originally Posted by superdave44 View Post
    I think Teddy Bear nailed this issue. The biggest problem from oversizing results in high humidity leading to mold and other health related issues. Take the $10,000 lawyer money and get a good contractor to install a whole house dehumidifier and feed yourself instead of the lawyer.
    Wait, I thought the primary problem from oversizing was wear/tear on the condenser?

    What is considered 'acceptable' humidity during air condition season? Also, humidity tends to rise so downstairs my be differant then upstairs (try running a humidifier in the winter in a house that has cathedral ceilings. Damn thing never turns off, but upstairs is pretty humid)

  9. #9
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,112
    Wear and tear.
    Excessive electric bills.

    A letter from a lawyer doesn't cost much. And can get results.
    Installing a dehumidifier, and saying all is well, is a bandaid.

    Selling dehumidifiers, is fine, but lets fix the real problem first.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  10. #10
    Join Date
    Jul 2008
    Location
    Rydal,Ga
    Posts
    84

    DO NOT pay a lawyer for NOTHING !!!

    Quote Originally Posted by beenthere View Post
    Wear and tear.
    Excessive electric bills.

    A letter from a lawyer doesn't cost much. And can get results.
    Installing a dehumidifier, and saying all is well, is a bandaid.

    Selling dehumidifiers, is fine, but lets fix the real problem first.
    Easy fix... Find out if the HVAC guy has a legitimate state license...

    Go to the SOS or License Board Revocations and Fines Page.... and print off a couple of Cases where HVAC guys misrepresented their license obligation to others consumers. SEND IT TO THAT HVAC GUY !!!!
    Most in our state loose their licenses for a minimum of 2 Years and $10s of $1000s in fines.... For Bad Behavior, Hack Jobs..... & NO MANUAL Js

    Let him sweat $$$$.... He will call you REAL SOON!!! GUARANTEE!!!

  11. #11
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,112
    Thats presumming his state has a HVAC license.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  12. #12
    Join Date
    Jul 2008
    Posts
    4
    Great suggestion, guys - please keep them coming and I will let you know how this works out. I did confirm that the SC building code clearly requires that the equipment "be sized based on building loads calculated IAW Manual J and other approved heating and cooling calculation methodologies." Duct systems have to be fabricated per Manual D, also per the building code. My town inspector gave me a copy of the code and he told me that the town can help force the builder to address the problem. The tricky part is going to be insisting that a different contractor performs the repairs and replaces the oversized unit and ducting. As far as I'm concerned the "three strikes and your out" rule applies with the original contractor who botched the install and two separate f/u visits to correct issues. In the last visit, to correct the problem of the freon lines being run across the attic service walkway, he just bent the line up, putting a big kink in the 3/4" suction line, which was hard too find under the insulation! This is just one of about a dozen examples of this horror story...

  13. #13
    Join Date
    Jun 2008
    Posts
    80
    IMHO and as others have suggested, going the distance on the legal front just won't pay for itself.

    • Stern letter or two from you with the Manual J
    • Letter or two from your lawyer. Tip: have them cut and paste parts of your letters to save money.
    • Better Business Bureau
    • Attorney Generals Office
    • Any state licensing agency

    If all this fails to get results, replace the system and donate the old system to Habitat for Humanity for a tax write off, if you can.

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