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  1. #1
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    Nov 2018
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    Replacing heat pump - Querstions to ask when getting quote?

    Moved in one year ago into our Roanoke, VA condo and want to replace the heat pump installed by previous condo owner. Current heat pump (SEER=14, HSPF=8) does good job of cooling but is quite anemic for heating. (Unit has been checked and per contractors, is working properly.)

    Am I correct that the contractor should conduct a Manual J HVAC calculation to determine the required SEER, HSPF, etc in order to determine the system to recommend?
    What other questions should I ask of the contractor when they quote a replacement unit?

    Thank you.

  2. #2
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    His are you sizing the equipment
    How are you sizing the duct work

  3. #3
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    Nov 2018
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    Thread Starter
    I should add that we will use the existing duct work. No new duct work will be installed.

  4. #4
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    SW FL
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    What is the REALisitic process?

    A specification MUST be Developed for Your selection of equipment AND SERVICES

    Specification will be based on ACCA Manual J ROOM-BY-ROOM CALC, S, & D.

    BLOWER DOOR TEST is required.


    https://www.acca.org/communities/com...e-0ae579bfe24a

    EXISTING Total Air flow rate AND ESP must be determined to evaluate
    whether the existing duct work would be sufficient.

    That's the only method to request and receive quotes that are directly comparable.
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  5. #5
    Join Date
    Jan 2014
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    Ask them to make sure they quote a AHRI matched system. If your system model says 14 SEER, does not mean it's automatically a 14 SEER rated system. The indoor selection determines the SEER, EER, HSPF, if you got the SEER and HSPF from a AHRI number then that's a different story.

    Ask them what's the labor warranty will be. Manufacturers have extended labor warranties for up to 12 years if that interest you.

    Make sure system gets registered.

    Does your system have a electric heater element? If so how will they size the heater element?

    Manual J gives the load calculation, does not include the SEER or HSPF, you should have an idea of what SEER you want instead of them picking one for you.

    You interested in a single stage or a 2 stage, you want a basic uncomplicated system, or a more complicated system?

    Why is your existing system anemic in heat mode?

    Doesn't 2nd stage electric come on when the HP can't handle the load as OD temperature drops? Does any part of your electric heat come on during defrost mode?

    Ask them if the existing lineset ( if reusing ) is sized correctly for the new system. Can't really do anything about the lineset if in a outside wall thou..

    Do you have any particular brands in mind, if not ask the bidding Contractors what type of defrost system the models they bid have, either a time/temperature or a demand defrost.

    Ask if they plan on elevating the OD unit off the pad ( if being installed on a pad ) to help the water drain away from the OD unit better while in defrost mode.

    Ask them if they will be doing a complete commissioning report on your system, some things to check is static pressure, defrost operation, amprege draw of motors and compressor. Electric heat operation, superheat/sub-cooling etc.etc. they should leave a copy with you.
    Last edited by Bazooka Joey; 01-14-2019 at 12:00 AM.

  6. #6
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    Nov 2018
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    Thread Starter
    (1) Existing system, anemic heat? WHen the temp at the return duct is 67 degrees, outside temp is 40 degrees, temp out of ceiling ducts is from 82-84 degrees.

    (2) How can I know what SEER I want? Isn't that determined by the cooling load required?

  7. #7
    Join Date
    Jan 2014
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    Quote Originally Posted by David138 View Post
    (1) Existing system, anemic heat? When the temp at the return duct is 67 degrees, outside temp is 40 degrees, temp out of ceiling ducts is from 82-84 degrees.

    (2) How can I know what SEER I want? Isn't that determined by the cooling load required?
    I suppose if it's a mismatched system to start with, or was not charged correctly, ( can't go by reading refrigerant pressures only to determine a correct charge ) or your moving to much air across the indoor coil, or if ductwork and AH are in a cold enviorment and your return duct is possibly leaking and pulling in surrounding air, need to keep the OD coil free of any snow also, that may be part of your problem.

    Cooling load calculation gives you the BTU needed, the SEER is what you decide on to purchase, higher the SEER the more energy efficient it typically is, meaning it uses less electricity than a lower SEER system. Reason for asking what type of SEER rated system you want.

    Ask them for the AHRI number that they bid if you want to find the SEER, EER, HSPF, total Cooling BTU. Go to this site

    Check at this site https://www.ahridirectory.org/

    14 SEER systems are the minimum standard across the US for a split HP system. Are you looking for a energy efficient variable speed blower or a energy efficiency multi speed blower motor, or the less efficient PSC motor? ( which I believe they will be discontinued in the somewhat near future, from what I read here )

    Your state or local utility company may have rebates if the equipment meets a minimum threshold.
    Last edited by Bazooka Joey; 01-14-2019 at 09:04 PM.

  8. #8
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    Aug 2002
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    You still will want the contractor to evaluate the current capabilities of the existing ductwork based off static pressure readings and inspect it for proper sealing and insulation values. If the ductwork is in the attic, if it not sealed or insulated correctly it will cause comfort and energy issues.

    Many system deficiencies can be attributed to poorly designed, sealed, or insulated ducts.

    Also with a heat pump, inverter style heat pumps provide better heating output than traditional style units.

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