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Posted by The Daring Dufas on July 29, 2009, 3:53 pm
The King wrote:
> On Wed, 29 Jul 2009 06:13:58 -0400, The King
>
>> On Tue, 28 Jul 2009 22:16:27 -0500, The Daring Dufas
>>> The King wrote:
>>>> On Tue, 28 Jul 2009 15:53:04 -0500, The Daring Dufas
>>>>>>> /Lars S
>>>>>> You could use NU-22 as a R22 replacement and you can use mineral oil
>>>>>> with it. BTW Stormy is a idiot posing as a hvac tech as his remark
>>>>>> about using a low temp ref shows. R-22 is not typically used in a low
>>>>>> temp applications. It can be used as such but it has special needs
>>>>>> when its used in low temp apps. Your application would be considered
>>>>>> high temp. Its all about evap temps not boiling points like the dumb
>>>>>> ass mormon thinks.
>>>>> Whenever I've used R22 in low temp applications, hell,
>>>>> even in refrigeration medium temp applications I always
>>>>> have to have a defrost system. A lot of the Domino's
>>>>> Pizza stores switched over to R22 in the walk-in coolers
>>>>> some years back and they all have to have defrost systems.
>>>>> I have to rebuild one here soon.
>>>>> TDD
>>>> Most of the time med temp ref is off cycle defrost. I suppose Dominos
>>>> wants 34 or cooler? as a target temp so a clock might be needed. In a
>>>> 36-40F box you shouldnt need anything but off cycle lessen it isnt
>>>> sized or adjusted right.
>>> The R22 walk-in coolers come from the factory with defrost
>>> timers. In order to get the 33-40 box temps, the evap runs
>>> a lot colder and of course the darn door does not stay shut.
>>> I like to set them at 35 because of all the meat products
>>> they stock and of course it helps keep the food temps where
>>> the health dept likes to see them with the door being open
>>> so much. I have one at a store I service that was an R12
>>> system originally, it's now running on 416a and keeps on
>>> running better than most. It has a three phase semi hermetic
>>> compressor, large receiver and pump down control, it's very
>>> reliable because it was installed CORRECTLY. The crap I
>>> see when some (techs?) throw them in is astounding. Oh darn,
>>> there goes my blood pressure.
>>> TDD
>> Evaporator temperatures are the same for the application (low - med -
>> high temp) regardless of what ref is used. R 12 med temp evaps run
>> at the same temperatures as an R 22 med temp evap. No need for a
>> defrost clock just because it has R 22 in it. There may be other
>> reasons for a defrost clock but the type of ref isnt one of them.
>
> I have a few beore I leave so heres my parting thoughts on your
> defrost problem. I use a 6F differential on the control setting. So
> with a 35F box cut out air temp would be 32F and cut in temp would be
> 38F. So at a target avg of 35.. yeah, you might want a defrost
> clock.
>
> I'd bump the temp up a half a degree or so to keep the air temps above
> 32F. That way you maintain a more consistant box temp which is good
> for the product and the consumer.
>
Since I'm not the worlds leading expert on refrigeration/HVAC,
I can only comment on my own personal experience with the various
equipment over the last four decades. I would have to research
the subject to give you any sort of proper and precise explanation.
All I can say is that every R22 walk-in cooler I've ever seen, has
had a defrost system except for the homemade ones that didn't work
until they were equipped with some sort of defrost system. Every
factory built condensing unit for an R22 walk-in cooler including
walk-in freezers has had some sort of defrost system. Passive for
the coolers, active for the freezers. I'm always willing to learn
new things so if you can tell me more and point me to the source,
I have no problem being corrected. When it comes to education, my
ego doesn't get in the way.
TDD
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Posted by The King on July 29, 2009, 7:41 pm
On Wed, 29 Jul 2009 14:53:24 -0500, The Daring Dufas
>The King wrote:
>> On Wed, 29 Jul 2009 06:13:58 -0400, The King
>>
>>> On Tue, 28 Jul 2009 22:16:27 -0500, The Daring Dufas
>>>> The King wrote:
>>>>> On Tue, 28 Jul 2009 15:53:04 -0500, The Daring Dufas
>>>>>>>> /Lars S
>>>>>>> You could use NU-22 as a R22 replacement and you can use mineral oil
>>>>>>> with it. BTW Stormy is a idiot posing as a hvac tech as his remark
>>>>>>> about using a low temp ref shows. R-22 is not typically used in a low
>>>>>>> temp applications. It can be used as such but it has special needs
>>>>>>> when its used in low temp apps. Your application would be considered
>>>>>>> high temp. Its all about evap temps not boiling points like the dumb
>>>>>>> ass mormon thinks.
>>>>>> Whenever I've used R22 in low temp applications, hell,
>>>>>> even in refrigeration medium temp applications I always
>>>>>> have to have a defrost system. A lot of the Domino's
>>>>>> Pizza stores switched over to R22 in the walk-in coolers
>>>>>> some years back and they all have to have defrost systems.
>>>>>> I have to rebuild one here soon.
>>>>>> TDD
>>>>> Most of the time med temp ref is off cycle defrost. I suppose Dominos
>>>>> wants 34 or cooler? as a target temp so a clock might be needed. In a
>>>>> 36-40F box you shouldnt need anything but off cycle lessen it isnt
>>>>> sized or adjusted right.
>>>> The R22 walk-in coolers come from the factory with defrost
>>>> timers. In order to get the 33-40 box temps, the evap runs
>>>> a lot colder and of course the darn door does not stay shut.
>>>> I like to set them at 35 because of all the meat products
>>>> they stock and of course it helps keep the food temps where
>>>> the health dept likes to see them with the door being open
>>>> so much. I have one at a store I service that was an R12
>>>> system originally, it's now running on 416a and keeps on
>>>> running better than most. It has a three phase semi hermetic
>>>> compressor, large receiver and pump down control, it's very
>>>> reliable because it was installed CORRECTLY. The crap I
>>>> see when some (techs?) throw them in is astounding. Oh darn,
>>>> there goes my blood pressure.
>>>> TDD
>>> Evaporator temperatures are the same for the application (low - med -
>>> high temp) regardless of what ref is used. R 12 med temp evaps run
>>> at the same temperatures as an R 22 med temp evap. No need for a
>>> defrost clock just because it has R 22 in it. There may be other
>>> reasons for a defrost clock but the type of ref isnt one of them.
>>
>> I have a few beore I leave so heres my parting thoughts on your
>> defrost problem. I use a 6F differential on the control setting. So
>> with a 35F box cut out air temp would be 32F and cut in temp would be
>> 38F. So at a target avg of 35.. yeah, you might want a defrost
>> clock.
>>
>> I'd bump the temp up a half a degree or so to keep the air temps above
>> 32F. That way you maintain a more consistant box temp which is good
>> for the product and the consumer.
>>
>Since I'm not the worlds leading expert on refrigeration/HVAC,
>I can only comment on my own personal experience with the various
>equipment over the last four decades. I would have to research
>the subject to give you any sort of proper and precise explanation.
>All I can say is that every R22 walk-in cooler I've ever seen, has
>had a defrost system except for the homemade ones that didn't work
>until they were equipped with some sort of defrost system.
Every
>factory built condensing unit for an R22 walk-in cooler including
>walk-in freezers has had some sort of defrost system. Passive for
>the coolers, active for the freezers. I'm always willing to learn
>new things so if you can tell me more and point me to the source,
>I have no problem being corrected. When it comes to education, my
>ego doesn't get in the way.
>TDD
What do you mean when you say "passive for the coolers"?
I agree every ref system needs some sort of defrost. it could be
either electric, hot gas, manual, or off cycle.
What you said was every r22 cooler needs a defrost clock. I don't see
why it would. Most refers are designed to have a 2/3 run time. The
other 1/3 is off. When it is off the space warms and any light
accumulation of frost should melt off before the next start. About
the only time I have seen or had to put a timer in is when the
customer wants the coldest beer in town and wants the coolers to run
30-35F. At those temps there is not enough off time above freezing F
to allow for a natural defrost and a defrost clock is needed.
Why is it an r 22 cooler needs a clock when a r 12 cooler didn't.
Just askin..
The evap temps are the same for each and every ref used for medium
temp work at a 10 delta. The refrigerants pressure/temp relationships
change with the type of refrigerant and they all have different
boiling points and properties. Some temps are cooler at x pressure
and some are warmer. They each have a different capacity per pound
circulated and all that jazz but those factors are why there are
different ratings for compressor duty and the type of refrigerant used
in them.
I hate to type and run but I have to pack the bike now and off to
Sturgis. :)
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Posted by on July 29, 2009, 9:21 pm
On Wed, 29 Jul 2009 19:41:10 -0400, The King
>I hate to type and run but I have to pack the bike now and off to
>Sturgis. :)
Have fun parking next to 150,000 other bikes just like
yours, you rugged individualist, you :-)
--
Click here every day to feed an animal that needs you today !!!
www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo online at www.pmilligan.net/palm/
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Posted by The King on August 8, 2009, 9:48 am
On Wed, 29 Jul 2009 21:21:18 -0400, .p.jm.@see_my_sig_for_address.com
wrote:
>On Wed, 29 Jul 2009 19:41:10 -0400, The King
>>I hate to type and run but I have to pack the bike now and off to
>>Sturgis. :)
> Have fun parking next to 150,000 other bikes just like
>yours, you rugged individualist, you :-)
Its not as bad as it looks on TV. :)
I got back last night around midnight after leaving the Sioux Falls
area at 5:30am. Ran in over eight hundred miles of pouring down rain
and a cross wind that was unbelievable. All in all it was a good
trip and we logged over 3200 miles.
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Posted by on August 8, 2009, 10:29 am
On Sat, 08 Aug 2009 09:48:05 -0400, The King
>On Wed, 29 Jul 2009 21:21:18 -0400, .p.jm.@see_my_sig_for_address.com
>wrote:
>>On Wed, 29 Jul 2009 19:41:10 -0400, The King
>>>I hate to type and run but I have to pack the bike now and off to
>>>Sturgis. :)
>> Have fun parking next to 150,000 other bikes just like
>>yours, you rugged individualist, you :-)
>Its not as bad as it looks on TV. :)
>I got back last night around midnight after leaving the Sioux Falls
>area at 5:30am. Ran in over eight hundred miles of pouring down rain
>and a cross wind that was unbelievable.
Sounds like a big fun ride ! Not ..... :-)
> All in all it was a good
>trip and we logged over 3200 miles.
You missed the hail ? Darn :-)
Was this Sturgis or an Iron Butt ride ???
--
Click here every day to feed an animal that needs you today !!!
www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo online at www.pmilligan.net/palm/
Free 'People finder' program now at www.pmilligan.net/finder.htm
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