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  1. #1
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,486

    A/C condensers for refrigeration?

    I've seen pictures of A/C condensers used for refrigeration systems? Does it work? Do they hold up?


    I ask because I have a supermarket customer that took me over to their warehouse today to look at a 15x15 walk in freezer thats been down for a few years. It had a leaking vibration isolator and a busted rod in the compressor. Also its r-502.


    They want it converted into a cooler, but don't want to spend a bunch of money because they just spent a ton on fixing up the refrigeration at the supermarket, and theres still alot of work to do there. I will have a whole bunch of gently used residential condensers from upcoming changeouts. If I hooked one of them up to this thing, change the TXV to R-22, and hook up the controls, eliminate defrost heaters etc, would this be a reliable system?

    The condenser is inside the warehouse where the temp is 60 in the winter and 80 max in the summer, so head pressure control should not be an issue.

  2. #2
    Join Date
    Jun 2006
    Location
    Omaha, Nebraska
    Posts
    861
    Lol, you must be in my neighborhood!

    Somehow it seems to work but I avoid those stores so I can't tell you how well they hold up. I would think the compressor would be operating outside of the design envelope so it might have a short lifespan. You'll probably need an off-cycle equalizing TXV for starting, and maybe a hard start kit, too if it's not a scroll.

  3. #3
    Join Date
    Jun 2005
    Location
    Las Vegas NV
    Posts
    1,152
    craig1

    I assume you meant a complete condensing unit, not just the condenser.

    If the A/C unit you have is a R-22 recip (not a scroll) then it will work at the lower SST's. In fact both Copeland and Tecumseh refrigeration H22 units thru 6 HP have a high temp 0 to +45 SST compressors that are also used in A/C units.

    The condenser will be large enough because there is more heat of rejection at higher SST's.

    What you don't have is a receiver, starting components (oem components, not a solid state start kit), heavy dutier pressure controls, heavy dutier fan motor, the room to mount anything extra and the overall design durability that a typical reefer unit has. You probably will lose the UL rating as well.

    So it will work, chincy and cheap as it is.

    Like any system, it needs to be matched to the reefer box load and the evaporator. List the existing evap that you have and we'll match it up. The rule is to add 15% to the freezer evaps listed btuh capacity to determine the capacity for a cooler (+20 SST)

  4. #4
    Join Date
    Dec 2006
    Location
    Middle Tennessee
    Posts
    11,347

    *

    Quote Originally Posted by craig1 View Post
    but don't want to spend a bunch of money
    when i hear this from a customer;

    i give the highest price possible, then give them my take it or leave it attitude



    .

  5. #5
    Join Date
    Sep 2002
    Posts
    12,712

    I used heat pumps

    Matched the HP, installed a check valve around the TXV, and opened power to the RV valve coil for the defrost. Defrosts the evaps in no time. <g>

    I did add a home-made two-way receiver to the liquid line though.

    Oh; and dual accumulators on each unit but I think they were over-kill.

    Worked real slick. Four 5 HP units. It's been running for years now.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

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