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  1. #14
    Join Date
    Jul 2011
    Location
    St. Louis
    Posts
    121
    Name:  before.jpg
Views: 82
Size:  34.9 KBI don't think the "before" photo linked in correctly. Here it is.
    In an infinite universe, not only are all things possible, all things are necessary

  2. #15
    Join Date
    Nov 2010
    Location
    MN
    Posts
    146
    Never saw one that bad. What was the diagnosis?

  3. #16
    Join Date
    Jan 2013
    Location
    Wisconsin
    Posts
    23
    Wow! Looks like they dug out a snow bank and put some shelving in it!!

  4. #17
    Join Date
    Jul 2012
    Location
    Western KY
    Posts
    1,221
    Wow!!! That's a good one.

  5. #18
    Join Date
    Jul 2011
    Location
    St. Louis
    Posts
    121
    From my understanding, it was an operational issue. The box had consistent icing issues for at least two years. Lots of activity, lots of door openings and too many defrosts causing excessive fogging.
    In a quick service restaurant, you have to live with a lot of door openings but you can do things with the fans and compressor control to prevent this from happening. A proactive defrost algorithm will create more defrosts when required and cut back on them when conditions warrant.
    I am not sure about how many defrosts were on the clock but sometimes service people (or owners who think they are service people) add more and more defrosts to try to cure the problem. That just makes it worse, too much heat and fogging in a freezer and soon you have the Crystal Cave.
    It is pretty, but let it go long enough and you will have to crawl in like and Eskimo!

    BTW- it looks like the freezer in my bachelor apartment, even my oxy torch couldn't touch it!
    In an infinite universe, not only are all things possible, all things are necessary

  6. #19
    Join Date
    Jul 2011
    Location
    St. Louis
    Posts
    121
    BTW-the box cleared simply with the pro-active defrost control. No chisels, or backhoes, were used. Time between the two photos is 5 weeks.
    In an infinite universe, not only are all things possible, all things are necessary

  7. #20
    Join Date
    Sep 2002
    Location
    Virginia
    Posts
    3,179
    Are you saying just by setting the defrost cycles different , it all cleared by itself ?

  8. #21
    Join Date
    Jul 2012
    Location
    Western KY
    Posts
    1,221
    Quote Originally Posted by BDOLIN View Post
    BTW-the box cleared simply with the pro-active defrost control. No chisels, or backhoes, were used. Time between the two photos is 5 weeks.
    Calling BS on that one. Sorry no offense but that cave was not caused by a lack of proactive defrost control. There are millions of freezers out there with no proactive defrost that do not freeze up like that.

  9. #22
    Join Date
    Jul 2011
    Location
    St. Louis
    Posts
    121
    The controller set up its own defrosts, it was not timeclock based. The controller looks at evap efficiency and triggers a defrost when the evap loses 10% of its capacity. With the fan and compressor control, almost all that ice was sublimated, going from ice to vapor, and being used to chill the room. The controller also terminates defrost with a sensor placed in the fins of the coil, where the ice is. This assures a complete defrost without overheating, steaming or adding extra heat to the room.
    Initial defrosts on the timeclock were 36 in 5 days, by the second week it was down to 11 in 5 days, I don't have current data but I suspect it is on the order of 3-5 in 5 days.
    In an infinite universe, not only are all things possible, all things are necessary

  10. #23
    Join Date
    Jul 2011
    Location
    St. Louis
    Posts
    121
    Quote Originally Posted by Tommy knocker View Post
    Calling BS on that one. Sorry no offense but that cave was not caused by a lack of proactive defrost control. There are millions of freezers out there with no proactive defrost that do not freeze up like that.
    You are absolutely correct, this is an extreme case and was 2 years in the making. If just a little frost is left on the coil during each defrost, over time the coil can bunker up with ice. The impulse is to add more and longer defrosts, in fact, this unit had been up to 33 in 5 days
    Name:  TH graphs.jpg
Views: 37
Size:  64.4 KB
    In addition, if a lot of ice is on the coil and the defrost termination is too high and the melting ice hits the heaters and hot spots of the coil, the steam or fog created will freeze elsewhere in the room. Improper fan delays exacerbate the problem, too. Without proper attention and the occasional full cleanout, this can happen. I am sure you have seen incomplete defrosts, some serious enough to grab fan blades and some simple enough to create small icicles on the ceiling.
    This was not caused by a lack of proactive defrost, it was cured with a proactive defrost control.
    In an infinite universe, not only are all things possible, all things are necessary

  11. #24
    Join Date
    Jul 2012
    Location
    Western KY
    Posts
    1,221
    Quote Originally Posted by BDOLIN View Post
    You are absolutely correct, this is an extreme case and was 2 years in the making. If just a little frost is left on the coil during each defrost, over time the coil can bunker up with ice. The impulse is to add more and longer defrosts, in fact, this unit had been up to 33 in 5 days
    Name:  TH graphs.jpg
Views: 37
Size:  64.4 KB
    In addition, if a lot of ice is on the coil and the defrost termination is too high and the melting ice hits the heaters and hot spots of the coil, the steam or fog created will freeze elsewhere in the room. Improper fan delays exacerbate the problem, too. Without proper attention and the occasional full cleanout, this can happen. I am sure you have seen incomplete defrosts, some serious enough to grab fan blades and some simple enough to create small icicles on the ceiling.
    This was not caused by a lack of proactive defrost, it was cured with a proactive defrost control.
    Sweet. So it wasn't a standard defrost system that caused your cave it was a defective defrost system that was neglected and abused over an extended time. Makes more sense now. That proactive set up seems incredible. Haven't seen them around here myself but defiantly worth a look.

  12. #25
    Join Date
    Jan 2013
    Location
    Wisconsin
    Posts
    23
    Yea the proactive defrost system is incredible, and really energy efficient.

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