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    MARTY21209's Avatar
    MARTY21209 Posts: 1, Reputation: 1
    New Member

    Aug 5, 2008, 03:49 PM
    Is my HVAC system installed professionally?
    HVAC installation.

    I recently purchased a house and subsequently did major construction to it. I have a number of questions regarding the installation of the entire HVAC system.

    The house is approximately 2800 square feet, and originally had 2 units. Each one is 24k BTU 13 sear. The air handlers for the units and the duct work were in the attic of the house. The registers were in the ceiling. Due to the construction that I had done, the system was removed from the ceiling and new air handlers and duct work was installed in the crawl space under the home. New registers were cut into the floor and the old intakes were removed and new intakes were created. The old 2 ton 13 sear units were kept, and are located outside.

    I do not know how originally the units were divided to handle the house, however, my contractor put the living space of the house on one unit (Unit #1) and the bedrooms on the second unit (Unit #2).

    A few weeks ago I noticed that cold air was not coming out of Unit #2. I thought that there may be an issue with the filter. So I went into the crawl space to change the filter. I was surprised. There was no filter on either of my air handlers. Furthermore, there was no place to put a filter. It looks like the units were missing the filter module. This finding became a red flag and led me to conduct my own layman inspection and I found a number of things that I am unsure if they are correct and acceptable or not.

    Please share your thoughts with me and tell me if what I found is unacceptable workmanship and the contractor should remedy the situation at no charge, whether this is completely acceptable, or whether it is OK workmanship, but not necessarily top quality.

    Thank you in advance.

    1) I saw that my air handlers do not have any air filters. Is this professional? Should the contractor install them at no charge? Should he now have to clean the coils due to the operation without a filter?
    2) The crawl space was the coolest place in the house . Due to Unit #1, there is significant air leakage into the crawl space.
    a. The silver tape used to secure the flex duct work and the insulation on the aluminum ducts is coming off in many places. . Is this professional? Should the contractor fix them at no charge?
    b. The insulation around the silver duct work gets blown out, very puffy, when the unit is turned on. It appears that when the aluminum ducts were connected that they were not sealed very well. Is this professional? Should the contractor remove and reseal the ducts at no charge?
    3) The flex duct work (on Unit #1) has a number of places where there are 90 degree turns. Is there an acceptable number of 90 degree turns allowed in ductwork installation? I have two flex lines that each one has a 90 degree turn, after two prior 90 degree turns in the trunk line. To me, the registers on these line do feel kind of weak.
    4) Is there a maximum length for flex lines. I have a few that run close to 24 feet.
    5) Is there a recommended number of supply ducts for a 2 ton system?
    a. Unit #1 has 8 supply ducts. Each one is 10 x 4. (according to my measurement). Should this unit have more or less supply ducts?
    b. Unit #2 has 4 supply ducts. Each one is 10 x 4 (according to my measurements). Should this unit have more ducts. If so, is it a nice thing to have or a requirement?
    6) Is it possible or even probable that since Unit #2 is no longer giving off cold air, that the limited amount of supply ducts caused the compressor to overwork and break?
    7) The kitchen is fairly large (16 x 20 feet) with an island in the middle. The flex duct that comes into the kitchen enters through the floor under the island. It shoots the air directly into the cabinetry and cools off all my pots and pans. Ultimately, air exists through a grill that was cut into the bottom of the cabinet like a toe kick. There is nothing directing the air towards this vent, but ultimately air does exit. My contract told me at the time, with conviction, that this is they way its done.
    8) Is one supply enough for a 320 sqr foot kitchen with a total of 10 linier feet of open wall into the dining room and family room? We originally asked for two vents and the contractor said it was not necessary.
    9) Unit #1 has 8 supplies (8 x 10) which is a total of 640 sqr inches of supply. The intakes however are located all centrally in the living room. There are 4 intakes, I measured them to be 6 x 14. Two are close to the ceiling and two are close to the ground. This is a total of 336 sqr inches for intake. Is this the correct sizing for the number of registers I have. Also, does it matter that half of the supplies are near the floor? (I have radiator heating so this is an exclusively AC system). Is anything wrong here? How does one calculate the sqr inch for needed for supplies?
    10) The intakes for unit #1 are located on the wall that is boxed around the underside of a staircase leading upstairs. This means that the intakes open into a huge cavity the size of under a staircase. Is this acceptable practice?
    11) Unit #2 has 4 supplies which is 320 sqr inches. Yet it has three returns of 6 x 14 centrally located which is a total of 252 sqr inches. Is this a correct ratio?
    12) Two of the intakes for unit #2 open into a cavity in the ceiling which is exposed to old insulation resembling shredded cardboard. I would think that since the old insulation is not sealed off from the intake suction, than its being sucked right into the air handlers, and causing dirt to develop on the coils as well as in the duct work. Should the contractor seal off the insulation from the intake path? Should he be required to clean the coils because of this and also the ductwork as well. (I have noticed a little dirt in the ductwork).

    Once again, thank you in advance for answering my questions.
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert

    Aug 5, 2008, 04:24 PM
    Your best bet is to call a different professional company for a ON SITE survey of all the problems. I say this because there are way to many irregularities and all we can do here is guess at the problems. For example you actually need velocity reading to really know what the duct work is doing. Has the system been professionally balanced? Did they install dampers in the duct?

    These are just tip of the ice burg question and the way to get a proper answer is with a engineer. All else is guess work.

    I am sure you had a building and electrical inspection by the Building department in your area. Call them and see what the plans showed for your system. Sounds like the contractor has a bit of correction work to do. Good luck.

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