FEATURE
INCORPORATING COLD CHAIN even 20 degree weather for that matter , but a -20 ° C inside requirement . On the latter , that is a 40 degree differential . Ultimately thermal radiation will be pressing onto the building and you want to keep that out – obviously , the longer you can keep that out the more efficient your system runs . With 30 % less ‘ power ’ to keep out that thermal radiation you will definitely have your hands full with scenarios that could play out in a number of ways .
With insulated panels there is also a structural component to consider . The actual structural element in lighter or less dense insulation material means less strength as well .
Incomplete or inaccurate information equals bad choices which has a direct impact on the overall industry .
“ This speaks directly to integrity as a business because at the end of the day it ’ s short-changing the customer because generally , they will have no clue – they rely on the expertise of the suppliers because it looks and feels like the right thing and they won ’ t even realise it when they are overpaying on their electricity bill per month . They also won ’ t understand why , but ultimately this eats away at their bottom line . In some cases , it can sink a business . Over a year you could be overspending on your budget by 10 to 20 % – these are big figures . A 10-year figure would reveal double expenditure , and so on ,” adds Zwick .
Above the insulation density , there are also so many different grades of steel , you have your regular galvanised steel and alu-zinc material that has a component of aluminium which offers corrosion protection . A new material now has some magnesium which is even more corrosive protective . The different components you put into the steel base give it different properties and qualities . These mixed materials get used in coastal applications where certain minimum ratios are recommended that don ’ t allow the panels to corrode . Naturally , the better the quality of steel , the higher the cost will be .
“ What prospective cold store investors need to take into account , and for those hard negotiators , is that the unfortunate reality that happens in the industry is that supply companies quote to get the job and then they start looking at how they can make money . Skimping on insulation quality ( because generally no one is the wiser ) and when done cleverly , the building will stand . It may not stand for 30 or 40 years , but long enough to reach the guarantee period ,” says Zwick .
He continues , “ Any supplier should supply what they promise to their clients but further the best application for the job . This is often confused where you get told to ‘ give the customer what they want ’, but the reality is that what the customer wants is not going to work . They don ’ t really know because they don ’ t have the expertise . Someone packing fruit knows all about nectarines or peaches and plums , but a cold room is just a cold room to them . What they need is a cold room that is efficient and that will have a life and not fall apart after a couple of years . We all need to do our part to make cold rooms economically efficient , electrically efficient – and structural integrity is not even a question .”
Doors , seals and panel joints are very important elements in any cold store . Doors are particularly important as they are one of the major human-interface factors that can be neglected .
Cold room requirements are also many , for example , will you be storing fruit or vegetables that will be coming from a refrigerated truck or after you have harvested at 35 degrees out from the field where produce needs to be cooled down very quickly in order to give a sufficient shelf life .
Timing is thus also an important factor because if you need to get produce to zero degrees within 5 hours or 10 hours , this makes a difference on the specs of your system . What now happens however is that some companies are selling a cold room to a client for R50 000 when they actually need a cold room that will cost R75 000 . The client then takes the R50 000 option but lands up spending an additional R35 000 to continually fix and maintain it , so these costs far outweigh what they should have been supplied from the start . Too often the industry exploits the users ’ lack of knowledge and trust .
“ Vapour barriers are another essential for any cold store . You have to make sure your cold room or store doesn ’ t have any moisture in it because moisture and frozen temperatures create havoc – moisture creates ice , and this creates expansion
and contraction , ice build-up blocks up the fins in your coils and because of its own insulation barrier , stops components from working , or you have a battle to reach required temperatures so economy literally goes out the door , not to mention time wasted ,” adds Zwick .
For the purpose of managing moisture , many companies have started deploying de-humidifiers in their cold rooms and
32 www . coldlinkafrica . co . za COLD LINK AFRICA • March / April 2021