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  1. #14
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    Oct 2008
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    Quote Originally Posted by NiHaoMike View Post
    More airflow should not cause a problem. The compressor will not be working as hard. Whether the efficiency goes up or down depends on many factors, but it's unlikely to be significant. It will slightly increase the minimum operating temperature, but a low ambient control will fix that.
    The unit needing repair was probably a countertop, glass door "Red Bull" merchandizing cooler, slightly larger than a microwave layed over on its side. A low ambient control probably costs more than the cooler he was trying to fix.

  2. #15
    Join Date
    Jun 2013
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    989

    Super High Efficiency RedBull Cooler ... review

    Quote Originally Posted by ECtofix View Post
    .......costs more than the cooler he was trying to fix.
    Mr E:
    even with an on-off schrader T - threaded limt switch set up?

    'spos any real issues could be solved blocking the condenser-air inlet a skish, if really was too much airflow, eh?
    Last edited by GT1980; 07-19-2013 at 04:49 AM. Reason: most clearly representing the full phrasing for to understand the....
    ... however, much work still needs to be done.
    CLOSED LOOP newer ratings are listed, but in numerical EER's Closed- is posted below OPEN LOOP EER's:

    http://www.energystar.gov/productfin...r=0&lastpage=1

  3. #16
    Join Date
    Mar 2013
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    44
    Quote Originally Posted by NiHaoMike View Post
    More airflow should not cause a problem. The compressor will not be working as hard. Whether the efficiency goes up or down depends on many factors, but it's unlikely to be significant. It will slightly increase the minimum operating temperature, but a low ambient control will fix that.

    Incorrect. there is such thing as TOO much subcooling, which will cause 'floating' head pressure. On the hunch that its an R-12 drop in system, presumely that abomination 134a, it's already stupidly low suction pressure is going to drop even further, and it will boil off prematurely, which WILL inevitably accumulate ice on the evaporator. It will run as if it was low on charge with even 30 more CFM on a self contained system. Half of its 1 foot coil will be useless, and if it does manage to get to setpoint, it will take twice as long with an eventual service call when the evap loses it's own airflow, and the coil is a block.

    However "a low ambient control will fix that" is indeed true. but who's gonna fork out the money to put a fan cycle control on a little merchandiser AFTER the fact? lol just put the right motor on it or a small diameter/pitch'd blade, and save a headache or two.

  4. #17
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,692
    Quote Originally Posted by GT1980 View Post
    Mr E:
    even with an on-off schrader T - threaded limt switch set up?

    'spos any real issues could be solved blocking the condenser-air inlet a skish, if really was too much airflow, eh?
    Probably doesn't have schraeder ports installed.

    Kinda makes it difficult to install a fan cycling switch based on pressure.

  5. #18
    Join Date
    Oct 2009
    Location
    Raleigh, NC
    Posts
    799
    The cooler will run just fine with the new fan.

  6. #19
    Join Date
    Jun 2013
    Location
    Austin, TX
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    641
    Quote Originally Posted by pr0dukt View Post
    Incorrect. there is such thing as TOO much subcooling, which will cause 'floating' head pressure. On the hunch that its an R-12 drop in system, presumely that abomination 134a, it's already stupidly low suction pressure is going to drop even further, and it will boil off prematurely, which WILL inevitably accumulate ice on the evaporator. It will run as if it was low on charge with even 30 more CFM on a self contained system. Half of its 1 foot coil will be useless, and if it does manage to get to setpoint, it will take twice as long with an eventual service call when the evap loses it's own airflow, and the coil is a block.

    However "a low ambient control will fix that" is indeed true. but who's gonna fork out the money to put a fan cycle control on a little merchandiser AFTER the fact? lol just put the right motor on it or a small diameter/pitch'd blade, and save a headache or two.
    That's unlikely to happen unless the unit is already near the bottom of its ambient temperature range. And a "low ambient control" can be as simple as a temperature based fan controller, no need to tap into the refrigerant lines.

  7. #20
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    Jun 2013
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    NORTHERN
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    989

    kinda woulda shoulda

    Quote Originally Posted by jpsmith1cm View Post
    Probably doesn't have schraeder ports installed.

    Kinda makes it difficult to install a fan cycling switch based on pressure.
    true,
    but what if could, was the intent.

    there's always more than the standard out where I live.
    T's for the thought anyways.
    ... however, much work still needs to be done.
    CLOSED LOOP newer ratings are listed, but in numerical EER's Closed- is posted below OPEN LOOP EER's:

    http://www.energystar.gov/productfin...r=0&lastpage=1

  8. #21
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    Jun 2013
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    NORTHERN
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    Quote Originally Posted by NiHaoMike View Post
    That's unlikely to happen unless the unit is already near the bottom of its ambient temperature range. And a "low ambient control" can be as simple as a temperature based fan controller, no need to tap into the refrigerant lines.
    would not the suction still run cooler-sooner, causing other issues, perhaps? -just looks possible, or would that state be too minutia-fied.?
    ... however, much work still needs to be done.
    CLOSED LOOP newer ratings are listed, but in numerical EER's Closed- is posted below OPEN LOOP EER's:

    http://www.energystar.gov/productfin...r=0&lastpage=1

  9. #22
    Thank you to all the helpful members of this forum who posted informative responses. I was greatly discouraged by the initial responses that I got, but I'm glad to see there are some nice folks here.

    It's true I don't want to sink any money into this merchandizer, as I got it for $20 off of Craigslist and it's truly a PoS... putting a Ranco thermostat on it already doubled its value. Since I'm running the cooler at around 55-65 F (beer fermentation temperatures) there hasn't really been any problems with the evap coil icing up.

    Stay cool, y'all.

  10. #23
    Join Date
    Nov 2009
    Location
    Richmond, working under tarps
    Posts
    495
    the slime that will build on that coil will be awe inspiring..

  11. #24
    Join Date
    Apr 2003
    Location
    Maple Grove, MN
    Posts
    1,301
    Quote Originally Posted by pr0dukt View Post
    Lmao. The coil is going to freeze up and he'll be back on here asking why CFM effected what's going on inside the box.
    Did you miss the part where he said he wants to run it around 60? This would tend to cause higher suction pressure, which would be balanced out somewhat by the lower head pressure caused by the faster condenser fan. I would think this would be a good thing. Even if this weren't the case, though, I don't think he would have to worry about it freezing up due to the short run times and warm box temperature.

    To marinosr, using a faster rpm motor to spin a fan blade designed for a lower rpm will require more horsepower. Check the amp draw when you are done. As long as the new motor isn't pulling more amps than what it's listed at, you should be ok.

  12. #25
    Join Date
    Feb 2012
    Location
    NY
    Posts
    128
    Quote Originally Posted by ammoniadog View Post
    Did you miss the part where he said he wants to run it around 60? This would tend to cause higher suction pressure, which would be balanced out somewhat by the lower head pressure caused by the faster condenser fan. I would think this would be a good thing. Even if this weren't the case, though, I don't think he would have to worry about it freezing up due to the short run times and warm box temperature.

    To marinosr, using a faster rpm motor to spin a fan blade designed for a lower rpm will require more horsepower. Check the amp draw when you are done. As long as the new motor isn't pulling more amps than what it's listed at, you should be ok.
    Nice comment, and helpful too. We should give him a break, after all the purpose is to make BEEEEEEEEErrrrrrrr! All sins should be forgiven for those who make beer.

  13. #26
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    Jun 2013
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    Hmm More CFM compared to load compared to 60deg box compared to... another situation refg

    Quote Originally Posted by ammoniadog View Post
    ...wants to run it around 60? This would tend to cause higher suction pressure, which would be balanced out somewhat by the lower head pressure caused by the faster condenser fan. ... a good thing. Even if this weren't the case, though, I don't think he would have to worry...As long as the new motor isn't pulling more amps than what it's listed at, you should be ok.
    significant "OK" , I agree b/c
    (something may be obvious) about the situation AND loading accounted for (in action) , -will determine if the tidal wave of cooling is too-fast enough, for to freeze too much between cycle-off's (and if cycling so, allows sufficient melting-off, if any melting is needed there)

    can always restrict some air thru, by maybe removing any present shroud, too
    ... however, much work still needs to be done.
    CLOSED LOOP newer ratings are listed, but in numerical EER's Closed- is posted below OPEN LOOP EER's:

    http://www.energystar.gov/productfin...r=0&lastpage=1

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