Category Archives: Refrigeration

Refrigerated Storage Tips

The mysterious world of refrigeration.

One thing that is certain through years of experience I can safely say, refrigeration whilst it’s a prescribed mechanical science (you would think it would be the same recipe/method/result all the time) Nothing could be further than the truth!

There is no shortage of work for good refrigeration technicians, systems are Always playing up somewhere, somehow for good reasons or sometimes no reasons, there are so many factors that are involved for the reasons why systems fail, both from the manufactures side and customers side.

Aside from ensuring you have your condensers cleaned at least monthly, in some extreme cases this may need to be fortnightly, and you don’t muck around with the thermostat settings on the unit too much there is little else you can do to help the unit work properly OR, is there?

Tip 1.

In 90% of cases your refrigerated unit or coolroom will NOT be even in temperature.

Tip 2.

Its all about Air Flow, In around the unit and for the exterior of the refrigeration motor.

  1. If you walk into your coolroom with a laser temperature reader (I’m not a fan of these they are too inaccurate in use) but its quick enough and simple enough to prove the point. Take a reading from each corner of the room, top and bottom (8 in total) plus directly under the fans and slightly to the back of them and then directly opposite the fans on the next available shelf.

What were your findings?

Depending upon on the point of the refrigeration cycle and the recent room usage I bet you found quite large variations of temperatures.

Did you find your Hot Spots?

That’s right, hot or warm spots nearly every room has them often on the same side as the fan location can be high or low. You may find for example this area could sit perhaps around the 5-6 degree mark whereas the rest of the room is 2-3degrees..

When you are sorting out your coolroom, this ‘warm spot’ is where you want to store your Fruit and vegetable for example, not your Oysters or chicken! Sounds too simple and ridiculous to be true, well it is, and I have seen it oh so many times, where the lettuce is almost frozen and the raw chicken isn’t even cold!

Now the Coolroom and Refrigeration mechanic reading this will fume and say ‘that doesn’t happen in my rooms’, great if that’s true, but in the real world it happens in 90% of cases. There can be many factors such as incorrectly sized fans, or condensers icing up which will lead to reduced air flow in the room. Or no coolroom curtain strips at the door which could be letting in too much warm air into a section of the room.

typical warm spot in a coolroom

As a Hospitality professional It’s your LEGAL responsibility to get to know your coolroom and its hot spots, it’s not acceptable when your in court explaining why 100 people that had the chicken are all sick because you didn’t know that part of the coolroom wasn’t cold!

We did a recent site survey for a large food importer to set up an www.i-temp.com.au temperature monitoring system. The coolrooms were massive, you could drive forklifts in them! What we found was that we needed to place many sensors in the room to get all the variable temperatures to be able to claim an ‘average temperature’ across the room. These were million dollar facilities and there was very little variance in the room, but there was some.

One of the reasons why the above example had little variance is because the operator had spaced and packed the room correctly.

This part is essential DO NOT OVERLOAD your coolroom and or refrigerator.

Take a walk into your local big supermarket, take a look at the refrigerated deli shelves or meat sections, note how they are loaded. Nice and even, never overloaded or just packed to the rafters in every little space is filled.

Nice neat lines evenly spaced between and from the front, not too much product on top of each other. They are ensuring that there is even airflow around the product the refrigerated air can move and pass through the layers. The difference between stacking and sorting the shelves like this IS the difference between the system being able to hold the foods at correct temperature or not.

Correct loading for commercial refrigeration

IF you were to load all that product higher/deeper and no gaps between I can guarantee it WILL NOT be at correct temperature.

Now your big name supermarket holds/stores/sells MILLIONS of dollars of food in each store, they cannot afford the risk of loosing product due to incorrect storage temperatures, or the risk of food poisoning. Their refrigeration costs are also one of the biggest expenses they have, they cannot afford to have systems working overtime either consuming excess power, in a business with very slim margins it makes a massive difference to their bottom line.

If you have problems with your staff overloading refrigerated cabinets/rooms you could do a lot worse than take them through the supermarket to look and see how they do it.

What about smaller refrigerated cabinets?

The effect can be even worse! Most systems have one fan area usually from the top of the cabinet or just the one side. If the unit is overloaded the far end of the cabinet be it bottom or the far end does not get cold enough, the air just can’t get down that end. Classically I have seen this happen in Ice cream and Gelato shops where they have often a 1 door vertical freezer for all their back up stock. The unit gets packed tight from top to bottom and side to side with tubs of product, packed tight.

Then the customer is complaining that the ice cream in the bottom of the freezer isn’t freezing properly and they are losing product. Its not the freezer it’s the user!

HOW Is the cold air that is blown from the top fan going to get to the bottom if there is no way for it to pass through all the product? Its not going to happen.

Once the freezer stock is reduced and the tubs are evenly spaced out of shelves with gaps between them to allow air to pass the through and circulate through the cabinet the problems is solved, product on the bottom is staying frozen.

Refrigerated Air MUST be able to circulate around the cabinet or room evenly.

Foodservice refrigeration loading

Now that we have seen that overloading is a problem, do you know that ‘underloading’ also can be?! What you say, can’t win, overload/underload.If you have a room or a cabinet that is empty the refrigeration system is just working all the time keeping air cool, sounds fine what the problem? Nothing really its just working its backside of wasting power! If you loaded your cabinet room up, lets say 60/70% capacity your refrigeration system will have to work less and save you hundreds and thousands of dollars in power!

How is that so? Thermal Mass the product (take a Coke fridge for example) once cold will keep its own cold in the mass of the product for a certain time frame.

For example, if you turned the coke fridge off, the cans of coke won’t be warm within say 15 minutes they, might go say from 1.5c to 5c but not warm. The thermal mass will take some time for it to warm up. But if that coke fridge was empty and we turned it off it would be a lot warmer in there than the same time, the air warm ups quickly, there is no MASS. The same happens with food products also, the bigger and heavier the slower they warm up as they have more cold mass. Think an icy cold cut of beef say a large top side or blade roast, its going to take some time for that big piece of meat to warm up.

So keep your cabinets and rooms at least 65% loaded your refrigeration systems wont have to work as hard.

Refrigerated beverage cabinet well stocked

2.

Air flow ‘around the system’, and the conditions of that air. This is the other airflow part, the air ‘around the refrigeration motor’ be it a self contained cabinet or a coolroom.  How well the air can be pulled in and expelled out of the refrigeration.

In its most simplistic form refrigeration works by extraction of air and changing the state of that air into the next stage. The method is to ‘pull air’ into the system and exchange that air into cold air into the cabinet or room. During this process the excess Hotter air that is pulled from the air that has been taken it is expelled out of the system, leaving just cold air to go into our cabinet/room.

How refrigeration works

Now the air that is ‘expelled’ during this process has to go somewhere, and it does. You will feel the hot air blowing back off a refrigeration (or Air Conditioning system) it might be off to the side, front.

The key with this air is we need to it to go away! We don’t want the refrigeration system to be sucking this HOT air back into to the system, we want it to suck cooler fresh air. And this is where so many of the breakdowns and problems occur, its known as ‘recirculating’ where the refrigeration system is breathing back in its own hot air and it then struggles to cope as it can’t pull down all this hot air.

Air flow again, you need to work out a way to get rid of this hot air if its being recirculated.

We see the above example often with vertical ref/frz cabinets where the ceiling height is low and the cabinet has a top mounted motor. There is just nowhere for the excess hot air to go and they start to recirculate their own air.

In the above example you could a) install a simple extract fan (like a bathroom fan) into the ceiling on intermittent timer to extract the hot air. Vents in the ceiling and or rear walls can help, but its pretty hopefully to assume the hot air will find a way out.
Having the room fully Air Conditioned (running 24/7) can help in the above example also.

So as well as allowing sufficient clean air for your refrigeration system to breath in, it has to be able to expel the air also. This is a big one.

Here are some other helpful tips below, and some more refrigeration facts and guides can be found here, https://www.airah.org.au/Content_Files/Special-Technical-Groups/Cool-rooms-SME-owners-and-operators.pdf

  1. Store Meats on the Lowest Shelves

Always store your meat on the lowest shelves of your appliance. Keeping your meat on the low shelves makes clean up easier if you have a spill, but more importantly this practice prevents potentially dangerous cross contamination. If any other food touches any juices or marinade from the meat, you must promptly throw those things away. If you store meat on the higher shelves, they are much more likely to drip down and contaminate the rest of your food, which can ultimately spread harmful bacteria to your customers.

  1. Leave Space Between Items

The cold air in your commercial fridge and freezer needs to be able to circulate. Although the impulse is to pack things in as well as you can to use every bit of the space efficiently, your fridge needs about three to six inches of space between the walls and the food products to get the best refrigeration. The circulation of air in your fridge prevents hot spots and uneven cooling and freezing.

  1. Keep Food Off the Fridge Floor

In order to prevent water or other contaminants from seeping into your food, it is important that you store all food off of the floor, including while in the refrigerator. While this is a health code requirement, not every person in your kitchen may be aware of the specific codes that will get your restaurant in trouble. In the heat of a rush of customers, it’s also easy to forget this rule. Having adequate shelving will prevent this problem. Make sure all your staff understands that this rule prevents food contamination and pest infestation in your commercial fridge. A note on the door is often enough to remind them.

  1. Store Delicate Produce Away From Fans

The fans in a commercial kitchen refrigeration and freezing units are extremely strong in order to encourage circulation, but this air flow can actually damage some of your foods. Berries and fresh greens are vulnerable to damage from these fans. In the freezer, storing food close to the fans increases its potential to get freezer burn. While you may need to fully utilize the space in your freezer, make sure to watch the labels and use the items closest to the fans quickly.

  1. FIFO; or First In, First Out

Product shelf-life and use-by dates are important for maintaining the quality of your foods. Make sure that you utilize the first-in, first-out (commonly abbreviated as FIFO) principle when organizing your storage units. When stocking, place newer items in the back of your fridge and freezer. If date codes are small, write the dates in bigger numbers on the box before you store it, and be sure to place the items so the dates are apparent. Make it easy for employees to see which products need to be used. Always use open items before opening anything new. This is an efficient method that will end up saving you a lot of money.

  1. Label Everything

Label the shelves. This may seem unnecessary, but mistakes can happen, so it’s good to have a reminder. Labeling lets someone else who isn’t as familiar with your system come in and find things easily, which can be helpful when you have new hires trying to figure out the kitchen. Labeling your shelves makes it apparent when something is out of place or completely out of stock.

Make sure every employee knows that anything that goes into the fridge has a label. This label should include both the day you made or received the product and the use-by date. It is important that you know when prepared foods, such as chicken broth or puddings, were created. Have a rule about unlabelled food, so no one forgets to label items. Make sure you have pens and stickers for easy labelling so this rule doesn’t waste unnecessary time in your kitchen.

 Reasons Why Organization Is Important:

  • High quality food is not cheap. Your storage plan maintains the integrity of everything you purchase so that it can be used and doesn’t go to waste.
  • You avoid those dreaded health code violations by following organization guidelines. Improperly stored food is one reason your restaurant might be fined or even shut down.
  • Utilizing your space effectively increases quality of the food.
  • Organization in your commercial kitchen creates a smooth operation. When your staff isn’t wasting time looking around for a specific food in an unorganized refrigerator, they can get back on the line quicker.
  • Disorganization in your fridge and freezer makes these units work harder, which means you’ll need to call for repairs more often when your food isn’t cooling appropriately.
  • There is less need for cleanup when shelves are organized. Food will have a place and things won’t be thrown in wherever it fits.
  • Clean up is easier when shelves are organized.
  • Ordering and restocking is easier when everything has a place. You can quickly see items that you need and won’t be looking for more cases in another place.

Organization Pays Off

Do you need more space in your commercial fridge or freezer? Before ordering more units for more space, make sure that the shelves in your current units are organized. Taking the time to do this may be a chore for your staff, and it certainly will take time away from their regular duties, but it will save you money in the long run. If you still need extra help, know that there are plenty of apps for kitchen organization that you should consider using.

Keep track of food waste and track the reasons you are throwing this food away. If it’s quickly going bad in the fridge or freezer, you should invest in better organization for better utilization of product. Don’t let a poorly organized fridge cost you money that should be going elsewhere in your business.

Customize your kitchen to your own individual needs. There are a number of different refrigeration systems that can be installed to keep your food at ideal temperatures before it is cooked and served. Take advantage of different products that work in your commercial kitchen.

Teach your staff the importance of fridge and freezer organization in your kitchen. This is an important foundation to have in your commercial kitchen, so you need to make it a priority. Make sure everyone knows how vital these rules are to your establishment.

If you have a real problem with employees with bad habits, try to influence staff with a reward for doing their work correctly after a week, a month, eight weeks, and so on so that everyone has more reasons to make it a priority in their own performance. You’ll see improvement quicker and create camaraderie within your business when everyone is working toward the same goals.

With so many variables it’s amazing that we can keep food cold at all! And it’s painfully obvious that ‘writing down’ a couple of temperatures per day on piece of paper hardly qualifies as an accurate record of the consistent temperatures  of a storage system over the longer 24/7/365 cycle.

The only way you can accurately obtain and prove such data is with digital technology, interdependently and accurately  recording data 24/7/365 , go to www.i-temp.com.au to learn more.

i-temp temperature monitoring

Monitoring Food Storage Temperatures – Using tech to help the Chef

TEMPERATURE CONTROL RULES Why is Temperature Control important?

Temperature control is important because harmful bacteria are a hazard present in many of the foods handled in catering businesses.

They also tend to multiply rapidly at temperatures above 5c, the higher temperature and longer the time exposed to the temperature the faster the bacteria growth . As bacteria are invisible to the naked eye and cannot be physically removed from food, all we can do is control their numbers.

There are two main ways in which temperature can be used to achieve this:

  1. We can destroy harmful bacteria, or reduce their numbers, by cooking or reheating and
  2. We can control their growth by keeping food hot or cold.

Lets look at cold.

The following practices are recommended to keep food safe. Your refrigerator should operate at an average of 5°C or below. These temperatures would then be the Critical Limits for Refrigerated Storage. Refrigeration of food temperature of 5°C or below is effective in controlling the quick multiplication of most bacteria in perishable food. It is recommended practice to operate refrigerators and chills at 5°C or below. Freezing of food should be done at -18c.

 

Time and temperature.

Just because food storage exceeds 5c for a short period of time does not mean that bacteria instantly grows at a rapid rate, your refrigeration being above temperature for a SHORT period of time is not dangerous.

Scientifically it has been shown that bacteria on high risk foods rapidly increase when the food is above 5c for periods exceeding 2 hrs, at 4hrs the food should be discarded.

The issue arises when refrigeration is cool but not cold! Eg A prep cabinet running at an average of 8-10c instead of below 5c. Whilst the bacteria won’t grow as quickly as if the food was at room temperature it will grow and at a dangerous rate, and this is where most hospitality operations get caught out.

I see so many refrigeration units that constantly run in the 5-10c zone, it’s scary. And to be honest in a hot kitchen environment it’s often difficult for small refrigeration units that have doors constantly being open and closed, especially with ingredient wells in the top to maintain correct temperature.

If you are only checking your refrigeration twice a day then you are assuming or guessing that the other 99% of the day the temperature is correct.

Aside from correct food safe procedure, ensuring proper refrigeration temperatures can result in improved shelf life of product and general quality of.

Food manufacturers and major suppliers don’t make guesses or assumptions that all their refrigeration temperatures are correct 24/7/365, they use digital technology to ensure it is, and it’s also far more economical to have technology to this and provided accurate records than employ staff to do so.

Using technology to help Chef’s

The ‘IOT’ world (internet of things) has arrived and its now entering the commercial kitchen space. Basically IOT means things that are connected to the internet , and hopefully add value to our lives.

We can now add temperature sensors to all refrigerated storage areas in the kitchen and have those sensors talk to the internet.

We can tell the sensors how often to talk to the internet and when to be alarmed about a set of data. From that we can direct the sensor to do something.

Basically if the sensor see’s that your coolroom is running at a temperature deemed to be too high for too long we can ask it to tell us, in most cases many people, normally via  SMS text and or email to a smart phone/pad or computer.

As long as the customer has access to the internet they can see current and past history of temperatures of their entire site at the push of a button form anywhere in the world!

With this information the kitchen manager/chef/food safety supervisor can make a decision on what needs to be done, could be a simple as shut the coolroom door properly , or check the food and perhaps discard.

The sensors collect  massive amount of data, basically they are checking your refrigeration temperatures 24/7/365 and then they are storing this data for future access or better still to produce a weekly report as evidence that food storage temperatures are at correct temperatures.

The minimum standard in Hospitality is to collect data samples twice a day , in some health food service sectors it maybe every four  hours. If you  have a lot of fridges this can be a very costly exercise, time wise, time=money. Why pay staff do do it (that may or may not do it correctly if at all!) when technology can do it for you?

Not only can technology do the task for a fraction of the costs of human labour it does it ‘independently ‘ , ‘accurately’ and with lots of data and evidence that can actually be called a ‘fair sample’ of evidence. Twice a day is nothing, it’s less than 1% of the day the other 99% is unaccounted for !

For further information on automated temperature monitoring visit www.i-temp.com.au 

Refrigeration Gas Set to change

Refrigeration Gas upcoming changes

As mentioned in previous post from the USA, some dates are starting to surface in the USA with regards to phasing out pretty much all the current refrigerant gasses that are commonly used in industry today, the move forward will be most likely to Hydro Carbon (HC) based gasses.

The first set of dates in the USA  are schedule for as early as March 2017. And whilst this is the USA it should be noted that Europe is on the same path, so its only fair to say that the Australasian market wont be far behind. The simple maths on damage to the ozone and environment by the current gas types compared to the new HC gas types is massively different.

Latest dates that I have seen for the Austyralian Market will see HC standard as of 2018 with an eventual phase out of existing gasses.

Reading between the technical lines, I’m seeing some issues with HC and charge amounts and issues with long distance remote refrigeration systems. The down side to these natural refrigeration gasses is that they are extremely flammable, having said that the amount of gas required in a cabinet is now tiny with HC units, as little a cigerette lighter full!

150gm is the maximum charge amount per cabinet for self contained systems. Where this becomes a problem is on really big refrigeration cabinets open fronted chillers, three door freezers for example they need more gas than this to work properly (achieve correct refrigeration temperatures) . In this example the solution may be to run multiple motors per cabinet which of course will add costs to manufacturer and then retail prices, or it may be a case of using individual cabinets instead of big multi door units.

The other challenge is with Remote and large units , for example Coolrooms. The compressor systems are much larger and require larger amounts of gas, whilst with HC gases the amount of gas required to run a system is massively reduces by at least 50% or more it’s still a large amount of HC Gas, and therefore is deemed a fire risk.

Fire Risk:

These new gasses have one down side, that is they are very flammable! However the amount of gas required to run say a 1 Door cabinet with HC use a tiny, so if an explosion occurred it would be extremely small (think cigarette lighter explosion if you had a naughty teenage/childhood you may recall the size!) so not too much of an issue however there are some recommendations on play to avoid accidental combustion ,  such as no heated burn off condensate trays and not installing near naked flame.

What does this mean for refrigerated drawer systems are char grills and cook tops, is yet to be seen.

Larger systems such as Coolrooms etc the fire risk is greater, Refrigersation mechanics and technicians are currently up skilling now in this area, in some states they may require special HC licence to work on HC refrigeration cabinets.

There is suggestion also that business owners will be required to log there refrigeration systems into the Fire Department also, so they have a data base of where big HC units are in case of fire at that location, they are prepared and warned of the possible dangers.

The cost to the manufacturing industry on changing processes , machinery , engineering and training to the new gases is massive , it will be a deal breaker for smaller companies. Larger international companies have been working with these new gasses now for years, investing millions of dollars of technology into making systems work on minimal gas, and also ensuring the fire risk is mitigated, solutions such as no spark, contactors, bushes, wiring have all been put years of R&D.

The Planet is going to be so much better off the moment we can get all registration and Airconditioning Gases to these new natural HC gasses, but there will be a lot of industry pain getting there.

For the end user consumer:

What does this all mean apart from you being kind to the planet?

MASSIVE RUNING COST REDUCTIONS, which saves you money, efficiency is 25-45% better on these new gas refrigeration systems, if you have multiple refrigeration units in your business this can mean Thousands of dollars of saved RUNING costs.

Inexperienced hospitality operators OFTEN OVER LOOK RUNNING COSTS commercial refrigeration is expensive to run and maintain, especially if you have purchased some cheap knock off copy refrigeration made normally in Asia.

Look at the KW rating on your cabinet (that’s even if they provide one) now times that by your KW$ per charge, now compare that cheap fridge you were considering against a quality cabinet with low KW rating, the money you thought you were saving upfront is elimated in most cases within a year! After that you are losing money each year, not to mention warranty out performance issues.

REFRIGERATION IS THE ONE AREA IN A HOPSITALITY OPERATION THAT ONLY FOOL’S SKIMP ON, I don’t think I can make it any clearer than that! It costs a lot to run, costs more when it breaks down and can cost you dearly if it’s not holding temperature properly and you have a food poisoning/safety issue claimed against your business.

The Flip side is that good commercial refrigeration will last many years, 10+ years is not uncommon on quality brands, compared to cooking equipment that’s probably 2-3 times longer for a busy operation.

RELIABILITY , there are thousands of HC systems already out in the international market place so the data is back on the performance and warranty statistics, Warranty issues have been more than halved in many cases with HC cabinets, so this may mean improved warranty terms going forward, which is a great thing for consumers!

Bottom line:

If you are in the process of choosing new refrigeration you should be discussing  HC and natural refrigerants with your supplier/ designer otherwise you could be in for some costly retro fit or replacement costs in the future.

For further information check out these articles, http://fesmag.com/home-highlights/13734-new-refrigeration-rules-set-to-take-effect-in-march-2017

http://www.fesmag.com/departments/green-tip/13143-myths-and-realities-re-new-refrigeration-rules

you could get in touch with the governing body to learn more,  https://www.arctick.org/ but from what I’ve have seen on that website it’s very typically government, lots of words, links and pages  but hard to find anything really concrete…but then again there are so many types and sectors that use refrigerant gasses, our industry is really a small fish in a pond, its a pretty big field to cover so maybe should cut them some slack…these guys probably are a better resource http://www.engas.com.au/about/about-hydrocarbon-refrigerants/ 

Suffice to say, that what is current, will be the past, so where possible select your refrigeration with HC gas now to save the pain and costs in the short to medium term future.

The confusing situation with all the above statements that needs consideration in your designs and selection of the new Natural refrigeration gasses is noted below. A really good resource to get read for detailed information is ‘The Australian Institute of Refrigeration , Airconditioning and heating.

 

Hydro Carbon Refrigeration
Hydro Carbon Refrigeration