Advice on Hussmann low temp island [Archive] - Refrigeration-Engineer.com forums

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coldkeeper1

27-09-2008, 12:53 AM

Dear fellows:

I´m having some problems maintaining the right product temperature in a new Hussmann ISF low temperature island. It´s used for frozen packaged fish steaks. Most of the time, the fish is rock-solid frozen, but I´ve noticed that from time to time the upper layer of the packages softens a bit. Merchandise is kept below the load line marked in the case.
The island manual calls for two defrost periods a day, but I had to add two additional periods in order to clear all the ice. I´m currently defrosting four times a day (every six hours), with a fail safe adjustment of 30 minutes, and a pressure setting of 550 KPa for the defrost termination pressure control (R-22).
According to my data logger, during defrost the product level temperature rises up to 2 deg C, and the island needs almost two hours (from the defrost initiation) to recover back to the usual -12 deg C.
Do all of these things sound normal to you or am I doing something wrong ?
One particular thing you might find interesting: for defrosting the evaporator coil, the equipment uses a heater which is not embedded in the coil but rather located in the air duct. That means that in order for the defrost to occur, the evaporator fan must be kept running during the defrost period as to move the heated air over the evaporator. I guess that some of this heated air, specially when the ice is mostly thawed, flows accross the fish in the load section.

nike123

27-09-2008, 07:04 AM

What is the evaporator superheat oh that island?

chillin out

27-09-2008, 11:11 AM

to recover back to the usual -12 deg C.
This seems a bit warm for a freezer.
Frozen food storage should be at -18 or below.

Chillin:):)

coolhibby1875

27-09-2008, 09:20 PM

im a bit worried that you stated that the thing is new and on r22.
why are you still using r22 on new instalations?

Porkington

28-09-2008, 10:32 AM

Cause he's 13, from Columbia and they couldn't give a toss about certain regulations?

Gary

28-09-2008, 02:13 PM

His age is irrelevant to the problem. The type of refrigerant in the system is irrelevant to the problem. Columbia's lack of concern for European regulations is totally irrelevant.

What matters here is the subcooling and superheat measurements.

coolhibby1875

29-09-2008, 07:15 PM

what about the lack of concern for the enviroment i ask by the way i was not having a go i am just suprised that a new instalation was still using r22 however while we are at it though maybe our cousins over the pond should wake up to global warming bet you drive a big gas guzzler to boot

Gary

29-09-2008, 08:45 PM

Let's not get our scams confused. As far as I know, R22 is part of the ozone depletion scam, not the global warming scam.

BTW, I drive a big ass gas guzzling motorcycle.

coldkeeper1

01-10-2008, 06:28 AM

Sorry fellows but I wasn´t online for a few days and couldn´t provide some follow-up comments.
First of all, I´m not 13 years old, I´m 23. I guess I misstyped my year of birth when I first registered for this forum: 1995 instead of 1985. Sorry.
Secondly, Colombia as well as the majority of the countries in this planet still belongs to the underdeveloped or in-the-way-of-developing bracket of nations. We well know the international concerns regarding the use of R-22, but we just cannot slash its use from one night to the following morning. It needs to be a stepped procedure, something that is taking place rigth now, as I´m sure it happened in the more developed countries such as the US and Europe at one time. Even the Montreal Protocol aknowledges this fact, and provides different timelines for developed and underdeveloped nations, when dealing with CFCs and HCFCs retirement. Currently, R-12 is not yet banned but increasingly unavailable in our countries, but R-22 is still the main battlehorse refrigerant in comfort a/c and medium-to-low temp refrigeration. Any banning of its use would bring even more hardship to our struggle when trying to become a developed nation.

coldkeeper1

01-10-2008, 06:33 AM

And about my problem with the island, the store where it´s operating closes on mondays and tuesdays so that it won´t be until tomorrow where I can get an update on the current SH and SC readings. I´ll keep you informed.

smilies

01-10-2008, 08:08 AM

Superheat is VERY important on these cases.
Also, make sure the HVAC system is not washing out the case airflow.
Ambient should be 75<meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 11"><meta name="Originator" content="Microsoft Word 11"><link rel="File-List" href="file:///C:%5CUsers%5CGERARD%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"><style>  </style><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 11"><meta name="Originator" content="Microsoft Word 11"><link rel="File-List" href="file:///C:%5CUsers%5CGERARD%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"><style>  </style>˚F and 55<meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 11"><meta name="Originator" content="Microsoft Word 11"><link rel="File-List" href="file:///C:%5CUsers%5CGERARD%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"><style>  </style>%RH or less.

US Iceman

01-10-2008, 02:11 PM

I´ve noticed that from time to time the upper layer of the packages softens a bit.

According to my data logger, during defrost the product level temperature rises up to 2 deg C, and the island needs almost two hours (from the defrost initiation) to recover back to the usual -12 deg C.

It seems you answered your own question here. Without more details available it appears the extra defrost cycles are the problem. I remember reading some specifications on display cases some time ago and believe their design requirements for store ambient conditions were based on something like 50% relative humidity and 72°F (22.2°C) dry bulb temperature.

If the store humidity is higher than this then the evaporators in the display case have to remove the moisture, which contributes to excessive defrosts.

bernard

03-10-2008, 07:56 PM

Hi If you have a heater at the front of the coil then the fans should be on during defrost.Check which probe the defrost terminates on as the stock on top should not be defrosting.When you say island,do you mean more than one cabinet if so ensure they are not all defrosting at same time.If its a single well cabinet then defrost 4 times a day for 30 mins terminating at + 12 for defrost probe in coil and 0 c for air off probe.Trim back to suit.If youv,e had icing issue then make theres no ice blocking air flow at rear of coil.

Regards B

Supertech87

13-03-2009, 04:26 AM

Ive seen this problem in hussmann coffin cases. What i ended up doing was adjusting the pitch on the fan blades chich created a better air curtain and maintainning the top product frozen. try it out

NoNickName

13-03-2009, 09:14 AM

Oh, I first thought it was either British Columbia or District of Columbia. It's COLOMBIA. :-)

joe magee

13-03-2009, 11:59 PM

Check a/c registers make sure air curtain is not being washed out. Make sure during defrost case term temp does not get warmer than floor temp or you could get infiltration. I use 55 degrees for term temp with 30 min fail safe. Two times a day should be ok. Conditions should be 72 ambient and no greater than 55 humidity. make sure the air is not spilling over the case. I had to use fan speed controls to slow the evap fans down on a brand new hussmann low temp island.

joe magee

14-03-2009, 07:58 PM

I have to throw in my two cent's about Gary. Gary's response to the global warming is the norm in this country. most of the techs I work with think it's a scam. It's a proven fact by all involved that it's happening and at a fast rate. I think techs have a responsibility to act. But if companies are using r-22 in equip we don't have much of a choice. Gary's response to check subcooling and superheat on that system show you it's a good thing he's retired.Those that can't, write books and teach.

Gary

15-03-2009, 05:08 AM

I have to throw in my two cent's about Gary. Gary's response to the global warming is the norm in this country. most of the techs I work with think it's a scam. It's a proven fact by all involved that it's happening and at a fast rate.

So what? If we assume that global warming is happening (they wouldn't lie to us would they?), that doesn't prove that (A) mankind caused it... or that (B) mankind can do anything about it.

We are going to spend a gazillion dollars to accomplish absolutely nothing. It will happen or it won't, no matter what we do or don't do.

Like everything political, this is about taking your money and telling you what to do.

Liberals are thieves and dictators, unlike conservatives who are dictators and thieves.

NoNickName

15-03-2009, 08:59 AM

Can we put politics away, please?

750 Valve

15-03-2009, 11:48 PM

Politics don't really have a place here, what does (and probably requires a whole new thread to discuss it) is that the majority of the industry world wide are doing their best to reduce GWP and ODP of installations both through refrigerant types, trade practices and equipment selection (lowering emissions) and here is one of the largest countries in the world with a high quantity of mechanics (and it appears trade teachers and authors) who believe its a load of balony and they should not have to comply. Typical conspiracy theorists, they think everything is a scam.

Get with the program fellas

joe magee

16-03-2009, 12:41 AM

I agree. I was at a seminar awhile back with a couple hundred techs and the gentleman giving the presentation was explaining a certain procedure and said, I quote- before you test the compressor, you must recover the refrigerant using the big blue sky recovery machine. He was given a standing ovation. He was representing one of the largest manufactures of refrigerant equipment.

Gary

24-03-2009, 03:00 AM

750 Valve

24-03-2009, 09:39 AM

Calling something a conspiracy theory doesn't prove or disprove it. That's just meaningless name calling.

you took a while to respond.... what did you sell a book or something?

msawert

30-03-2009, 10:49 AM

is it just one coil in the bay or all coils in the bay, normaly we run them with 2 defrosts a day at 50 min and a termination of 15 deg c, we have never had to change pitch, is there any ice build up in he back wall? is it at the end off the liquid line and not getting enough refrigerant? humidity dosnt normally effect the performance, over here we run at 95% humidity at 35 deg c for all of summer

nike123

31-03-2009, 02:16 PM

So what? If we assume that global warming is happening (they wouldn't lie to us would they?), that doesn't prove that (A) mankind caused it... or that (B) mankind can do anything about it.

We are going to spend a gazillion dollars to accomplish absolutely nothing. It will happen or it won't, no matter what we do or don't do.

Like everything political, this is about taking your money and telling you what to do.

Liberals are thieves and dictators, unlike conservatives who are dictators and thieves.

Here (http://www.larouchepub.com/eiw/public/2007/2007_20-29/2007-25/pdf/33-37_725.pdf) is something what support your look at things!;)

Keep posting, my friend!

Gary

05-04-2009, 10:06 PM

Here (http://www.larouchepub.com/eiw/public/2007/2007_20-29/2007-25/pdf/33-37_725.pdf) is something what support your look at things!;)

Keep posting, my friend!

Thanks for the link, Nike. I wonder how many here will bother to read it.

Science runs on government grants. If you don't tell the politicians what they want to hear, you don't get the money. Scientists cannot be trusted any more than politicians can be trusted.

And anyone with a conflicting opinion is labelled a crackpot conspiracy theorist by the political propaganda machine (aka the media).

But wait... the media wouldn't lie to us, would they? Well... let's think about this.

The fat cats bribe the politicians... oops, I mean they contribute to political campaigns. Then the taxpayers provide matching funds. (That's right , folks... you double the fat cat's bribe).

And where does the bulk of this money go? It goes to the media for political advertising. I wonder how much money goes to media entities who disagree with politicians? My guess is zero.

Gary

05-04-2009, 10:28 PM

I am amazed at how gullible people are.

My all time favorite scam is the "stick it to the evil corporations" ploy. The media pushes it, the public demands it, and the politicians pass a huge tax on the evil greedy corporations... and then... the corporations pass it along in the price of the products and/or services... and we buy the products and services. Wake up, folks... it's a hidden sales tax... and you are paying for it, not the evil corporations.

750 Valve

06-04-2009, 11:15 AM

Gary you are in the wrong place...

Try here (http://www.politicalforum.com/), here (http://www.abovetopsecret.com/) or maybe even here (http://www.clubconspiracy.com/forum/)

joe magee

07-04-2009, 03:43 AM

I agree, why are we on this topic? I thought the question had something to do with a low temp tub.:)

nike123

07-04-2009, 03:51 AM

Since we did not get any superheat and subcooling reading, only thing what we could do at that problematic tub, is talk about politics until we get these data.;)

750 Valve

07-04-2009, 10:13 AM

Since we did not get any superheat and subcooling reading, only thing what we could do at that problematic tub, is talk about politics until we get these data.;)

nice response nike:D

coolhibby1875

07-04-2009, 05:17 PM

hi folks i put my hands up and say it was me who started this debate (sorry) i was just surprised that in the first post he said it was a new instalation and was put in with r22

Colin G

07-04-2009, 06:21 PM

hi folks i put my hands up and say it was me who started this debate (sorry) i was just surprised that in the first post he said it was a new instalation and was put in with r22

for your punishment you shall be burned on the heath with the witches at dawn!

do you have anything to say in your defense regarding thread misconduct? :rolleyes:

coolhibby1875

07-04-2009, 08:06 PM

guilty as charged !

bowral fridgy

12-04-2009, 07:04 AM

My only experiece with KysorWarren cases utilising defrost element in front of coil is it just doesn't work. Once a section of finned coil become blocked with ice, trying to blow hot air through it is a waste of time - the airflow just diverts through the unblocked sections Hot gas defrost is the only way to go. These open top freezers are only suitable for stores with effective air conditioning maintaining RH below 50% in my opinion.
And stop picking on poor Gary. He's an American after all and probably doesn't know any better. Anyway he's quite right in one respect - the GWP of R22 is only 4300 as opposed to 5000 for HFC 404A (20 yr cycle)
Coolkeeper did you say -12C ? Seems a bit warm for frozen fish but then again it could be more than adequate for the cocaine hidden inside the packages. I mean if you believe the mainstream media thats the only form of produce coming out of Colombia isn't it ?

750 Valve

12-04-2009, 10:42 AM

R404a is a little less than 5000!!! Between 3200 and 3700 depending on what info you read, but we won't mention ODP at all...

joe magee

12-04-2009, 04:44 PM

That's terrible picking on us poor Americans. :p. You are correct, the single deck Kysor Warren cases will ice IF the temp is set too low. Any temp below -20 and you will be deicing in a few months. The problem is ,to keep ice cream cold (high fat content ice cream) you need to run that case at -30f. Discharge air. The solution I found was to put a low wattage heater behind the coil wired in with the front heater. I haven't had an issue since. lousy cases design? Don't have that issue with the hussmann sd cases though.:D

jack smith

18-04-2009, 01:00 PM

was on a course about r22 phaseout and the new leak testin procedures. cant understand how cars are not included in this when each car holds approx 700grams of refrigerant and are prone to leaking. anyone any thoughts on this

750 Valve

19-04-2009, 01:52 PM

well as far as I understand R22 is not used in cars. They used to be on R12, which was phased out and R134a was introduced, this is going to be phased out due to the high taxes on it in EU based on its GWP (1500ish), the alternatives being Co2 transcritical systems or a newly developed alternative that is said to be VERY costly to produce and requires a committment for the major European car manufacturers before it will be put into production. Was talking with a BOC exec about this just the other day

RGAR

16-05-2009, 03:04 PM

Try moving the termination probe to where the ice starts to build, this will make sure the defrost lasts as long as required.

parky630

17-05-2009, 02:03 PM

recover rate is to long on a case of this type, should be less than 10 minutes ..... check valve for crap, sizing, setting and adjust and move along, defrost should always terminate on temp and should be around 15 min. unless you are picking up lots of humidity and building lots of frost on the coil and thats why you added more defrost to compensate, always follow the manufactures design and settings it's their case and they know how they run and now that you have hit all their numbers its on them to tell you why it don't work

sling the store for humidity and look for infiltration from an air vent blowing in the case before you call them
I'm impress for for actually giving a darn about product integrity at your age most guys i know just walk on by

even one box outside of the load limit can effect the operation of this case over a period of time with it picking up of store humidity and the defrost cycle can't catch up so after a few days you have frost build up in the returns blocking air flow and now the case will take longer to recover because your valve is only opening half way because its not picking up the required heat load and your off and building more frost so you add a couple of defrost , i hate tub cases

good luck

Victor537Boston

09-06-2009, 01:47 AM

im sorry i was reading the forum and halfway through lost all interst with some of the post not helping the one asking the question. If you dont have a opinion to help resolve his issue than dont speak any other, thats rude. You insult the poor guy instead of help. I wish I had more experience on the hussman coffin case. I have never had that problem before but wow some of you are jerks. Thats my 3 cents. Good luck cold keeper

Mark

09-06-2009, 08:08 AM

MBdrinker

14-06-2009, 12:48 PM

hay, what is the sst rated at. Run the rack accordinding to it. If all else fales maybe a SORIT will help