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Thread: Want to use my existing central A/C to chill water tanks

  1. #101
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    Mar 2013
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    Quote Originally Posted by dave sulz View Post
    How do you think a compressor hat runs above freezing work below freezing. I hate ***** {ranting deleted}
    Should work great if it's not flooded. And, it has.

    Back up, rethink what you say. It may not be overly efficient or pretty but the OP likes it and it works. Many things were thought of the same way in the way you talk, but are considered standard now.

  2. #102
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    great work!

  3. #103
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    Aug 2016
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    Thread Starter
    Sorry I missed this post! That's interesting!

  4. #104
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    Aug 2016
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    I've really been enjoying the hot weather we've had over the last week! It gave me several days of much anticipated testing and development! It got up to 94 degrees F a couple days ago, and the "Cold-Pacitor" was able to keep the 1st floor at or below 73.2 F during peak pricing (3PM - 8PM) with just a few minutes of assistance at the end from the LG mini split.


  5. Likes HVAC_Marc liked this post.
  6. #105
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    Feb 2010
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    Newnan Ga,
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    Quote Originally Posted by dave sulz View Post
    How do you think a compressor hat runs above freezing work below freezing. I hate nonsense. I'm not smart but recoconize dumbass. Sorry stupid should be told
    Wow you should be outed..you don't belong on this forum...

  7. Likes Gernby, HVAC_Marc liked this post.
  8. #106
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    Aug 2016
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    Thread Starter
    Do any of you guys have any suggestions about how I can derive some sort of "performance index" based on weather parameters, indoor parameters, power usage, and / or electric cost, in order to dial in my system a little quicker? It doesn't have to be elegant, and could even be unit-less. I just need some way to know whether some change to the system causes a positive or negative result.

  9. #107
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    Sep 2002
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    1. No heat change process is 100% efficient - something is always lost in each step of the exchange process.

    2. The nature of an A/C evaporator's design is such that it cannot tolerate any frosting.

    3. So the refrigerant evaporating temperature cannot fall below about 30-32 F.

    4. The approach of the evap is unlikely to be less that 10, and may be greater, so your minimum air 'off-the-evap' temperature is unlikely to ever be less than 42.

    5. Getting the heat out of water without large surface areas is difficult and slow.

    PHM
    ---------



    Quote Originally Posted by Gernby View Post
    Hi, I'm working on an HVAC project, and am trying to figure out the best way to chill some barrels of water. My current plan is to buy an air-to-water heat exchanger (like a car radiator), and install it in an air box next to the air handler in my attic. I would connect that box to the air handler with 2 flex ducts (1 to the return side and the other to the supply side). I would also put a motorized damper in one of those ducts to prevent air flow through the air box during normal operation.

    The damper would be closed almost all the time, but whenever the AC is running AND the thermostat is about to turn the system OFF, I would have a "piggy-back" controller take control of the system. If the temperature of my water tanks is higher than I want, then the controller will keep the AC running while the motorized damper is opened up and water starts pumping through the heat exchanger. While running like this, I believe there will be very little air flowing through the rest of the ducting, since most of the air should be "short circuited" through the heat exchanger.

    I haven't done the math about how large the ducts and heat exchanger need to be, but it seems that as long as I can pump enough heat through the heat exchanger to maintain 15-20F across the evaporator coil, then I should be able to chill the water down near freezing. That might take a large sized exhanger and water pump, but it seems possible.

    Do you guys agree? Am I correct that the air looping over and over between the evaporator coil and exhanger can be super-cooled (at or below freezing), as long as a 15-20F temp drop is maintained across the evaporator?
    PHM
    --------
    Socialism is a zombie. It never dies - even though it is constantly decaying and decomposing.

  10. #108
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    Aug 2016
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    I'm curious if you guys can help me figure out the best way to reconfigure my system for summer. I've had the chiller running inside the house with great results, but now that it's getting so hot, I need to relocate the chiller outside somehow. Does anyone know what about this condensor makes it "indoor", or what it would take to make it an "outdoor" unit? It's not clear whether the indoor designation is due to it needing to stay dry, or if it has to do with ambient temperature.

  11. #109
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    An outdoor unit is protected from water and may have low ambient pressure or fan cycling controls.

  12. #110
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    Quote Originally Posted by HVAC_Marc View Post
    An outdoor unit is protected from water and may have low ambient pressure or fan cycling controls.
    If I kept it dry, and only ran it during the cooler hours, like 10 PM to 10 AM (continuous), do you think there would be much risk?

  13. #111
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    One option I'm considering is to relocate the chiller to my garage, but I would need to improve ventilation in the garage to keep the temperature down.

  14. #112
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    Quote Originally Posted by Gernby View Post
    If I kept it dry, and only ran it during the cooler hours, like 10 PM to 10 AM (continuous), do you think there would be much risk?
    There's lots of risk. Moisture alone can cause things to become energized. Things that arent supposed to be, like your body.

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