Regular Member - bad email address Contact the Admin
I just read an article about both the positive and negative sides of hot gas defrost systems. Regarding the negative aspect: high thermal stress on both the evaporators and pipes due to cyclic wide temperature variations, leading to the creation of high stress points, a possible source of leaks, WHAT SHOULD BE THE AVERAGE LIFESPAN OF THESE EVAPORATORS, before having to discard them ?
Professional Member*
Originally Posted by rackrookie
I've seen coils last 20+ years - I've seen coils buckle in less than 5.
I dunno...........does it make the average 12.5 years?
Think it all depends on length of run, temperature of gas, differential pressure, defrost frequency and duration, store humidity, case design, and on....and on..an on........
Don't think many here would be able to give you an "average" - too many variables.
"The problem is the average person isn’t tuned in to lifelong learning, or going to seminars and so forth. If the information is not on television, and it’s not in the movies they watch, and it’s not in the few books that they buy, they don’t get it" - Jack Canfield
Educational Committee/Professional Member*
mt pretty much summed this one up.
I love the smell of phosgene first thing in the morning:
To apply for professional membership click here
Educational forums are open.
If you would like to submit a link or an article or other related info to the EF. click here
Professional Member
"Most" coils should do alright with hot gas defrost. I have seen more problems or leaks created due to poor piping practices, cracks on liquid line elbows etc., which could have been prevented with proper piping allowing for flex and/or liquid line inadvertently being silfossed to suction(guarenteed to rip suction line wall eventually). 3/8" 90's should be avoided.
Watts New, Ohm My, I been Electrically Commutated. Are U2.
Membership Chair/ARP Committee / Professional Member*
Thermal Shock? Come on now.
The temp goes evenly from 0 to 100 and back - there's no thermal shock in that. The range with electric defrost would be far wider and the heat points way more concentrated.
As something to worry about - this would be right next to Mars attacking.
PHM
--------
When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
Professional Member
I agree. Maybe the medical field should go back to heaters. Not!!!!
It's what you do that defines you.
Professional Member
WHAT SHOULD BE THE AVERAGE LIFESPAN OF THESE EVAPORATORS, before having to discard them ?
In 95%+ of the display cases I have seen, the coil has outlasted the rest of the fixture. Despite our techs wishes our company services many refurbished cases that still have the original coil but may have been reskinned, reinsulated, converted from electric to hot gas, R22 to R507 etc. and still the coil lives.
One of the problems I see is that these cases were not designed for HG and the tendency is for the drain pans to freeze up whilst the coil defrosts fine. Adding a HG drain pan loop and required check valves would help. That or not rerouting the cases from the scrap heap in the first place.
Watts New, Ohm My, I been Electrically Commutated. Are U2.
Posting Permissions
Reply