heavy frost in ice cream cooler

[garrettw]

I'm a student and our refrigeration instructor retired, so I'm turning to you for answers. At my grocery store the ice cream section of the frozen case produces alot of frost. However the other sections do not, even though they aren't seperated and are all the same temp.

At first I thought it was because the fans didn't shut off during defrost which would blow the water droplets out freezing them. But if that were the case shouldn't the entire case be doing this and not just the ice cream section. Any input?

[Freezeking2000]

I hate the section with the round containers!

[icemeister]

It's the round containers.

[270wsm]

Whats the connection between round containers and frost buildup?

[stat]

Check and see if the fan delay is working in that section.

[dirtyboy103us]

time for defrost should be at nite and check fans off during defrost and only one in 24 hrs. next defrost deferential setting, terminating on temp not time and last txv clean and adjusted

this case i assume is a set of glass drs.on a rack
its picking up high humidity during the day when they fill it or lots of customers are standing there looking for product with door wide open

some of it you can be prevented with proper settings on the equipment not all... with loading techniques and shopping patterns defrost in the middle of the nite
also store humidity can effect this

a little research on the manufacturer's case and condenser/rack settings would go along way to preventing this

[razorback]

Also make sure all the doors close tight and the gaskets are in good shape.

[icemeister]

Originally posted by ace12
Whats the connection between round containers and frost buildup?

We had a rather good discussion about this two years ago:
http://hvac-talk.com/vbb/showthread.php?threadid=54681

[stooge]

more than likely you'll find the one of the doors hanging open... check, than adjust or replace torch rod..
hopefully it will be that easy.. maybe not

[icecuber911]

Originally posted by garrettw
I'm a student and our refrigeration instructor retired, so I'm turning to you for answers. At my grocery store the ice cream section of the frozen case produces alot of frost. However the other sections do not, even though they aren't seperated and are all the same temp.

At first I thought it was because the fans didn't shut off during defrost which would blow the water droplets out freezing them. But if that were the case shouldn't the entire case be doing this and not just the ice cream section. Any input?

I have noticed that if you have two circuts side by side with different defrost times then you will have warm air going into the case that isnt defrosting. I istalled a couple dividers for giggles to see if it helped. So far both circuts look good as for frost.

[garrettw]

Thanks guys, you helped get the wheels turning. I appreciate it.

[mccool]

Lots of good suggestions, the 1 defrost at nite as suggested by "dirtyboy" is important I find. Interesting to note that older models of glass doors had 2 defrosts a day recommended but the norm is now 1 a day at night (eg.2 am)
The fans, lights, frame and anti-sweat heaters should all be shutting off during defrost and any required drain pan heaters should be coming on. Many older cases will have the klixon's and/or wiring bastardized for a # of reasons. Store did not like the lights shutting off during defrost, case was refurbished and/or wired incorrectly, drain pan heaters do not match original amps or proper mounting plate, etc. etc..

You should obtain the manufacturers specs. and check that required control functions and settings are being met during refrig. and defrost.

Is this electric, hot gas or kool gas defrost? Old, new or refurbished ? Wire or solid shelf? Solid or slotted/holed back wall panel?

Many things to look at in this scenario. Start with basics, like 1.infiltration (door gaskets, unsealed holes on installation) 2.txv superheat setting 3.case temp. setpoint(-12ºF) 4.proper operation of klixons and relays
5. 1 defrost at night. # order can be reversed but all should be checked.
After that you are in Macgyver? country, (lots of prime time on your own time) Good Luck!

[cooker]

I also agree. There are several possibilities. The case manufactor info. is a big time saver. With this issue being isolated to to one compartment I would really lean torward product not being rotated, air infilitration, defrost termination failing, or TXV issue. Pay attention also to the frost on the coil. No fans on with a wet coil grasshopper. Good luck. When all else fails use C-4.

[hitachijb]

through away the old junk