MANAGING HUMIDITY IN COLD STORE INSTALLATIONS COTES.COM MANAGING HUMIDITY IN COLD STORE INSTALLATIONS COTES.COM HUMIDITY – THE INVISIBLE PART OF THE CONTROL EQUATIONS DIFFICULTIES GET DEALT WITH Cooling goods for low-temperature storage can often lead to big problems with unwanted ice and condensation – all caused by humidity. Humidity is is an invisible parameter that can ratch up operating costs and punch big holes in customer satisfaction. Cotes adsorption dehumidifier solutions enable you to tackle the fundamental reasons why ice and condensation even arise – giving you full control over conditions, lower operating costs and greater customer satisfaction. COTES.COM CONTENTS 07 TARGETING SYMPTOMS OR ROOT CAUSES? 08 Do you have a humidity problem? 13 PRACTICAL ISSUES COMMON IN COLD STORE SET-UPS 14 Where ice and condensation form 16 A plethora of practical problems 18 Have you got problems with ice and condensation? 23 NO TWO COLD STORE SET-UPS ARE THE SAME 24 Your challenges are unique 26 What needs to be considered? 28 Different conditions – different solutions 30 Different refrigeration and freezing set-ups 33 HOW TO TACKLE ICE AND CONDENSATION 34 Defrosting makes a difference 38 The dehumidification approach 39 How it works 40 What does it cost? 41 What really happens? 42 How it’s installed 47 Recommended action 49 HOW COTES CAN HELP 50 Cotes recommends 54 Prevention is better than cure 56 Effective humidity management brings down your operating costs 57 The benefits add up 58 Cotes All-round 59 Cotes Flexible 61 EXPERTS IN MANAGING HUMIDITY TARGETING SYMPTOMS OR ROOT CAUSES? DIFFICULTIES GET DEALT WITH SYMPTOMS OR CAUSES? Cooling goods for low-temperature storage can often The problem is that this is only dealing with the lead to problems because humidity present in the air symptoms – not the root causes. Patching not makes ice and condensation form – resulting in loads preventing. of bothersome practical difficulties and revenue- nibbling costs. Cotes adsorption dehumidifier solutions enable you to tackle the basic physics of why ice and Most companies that operate refrigerated or freezer condensation even arise – giving you full control storage facilities have learned to tackle the normal over conditions, big savings because you don’t day-to-day ice and condensation problems, or need to spend money on costly preventive have invested in ways to keep them to a minimum. measures, and satisfied customers because goods Efficiency, customer satisfaction and profit margins don’t get spoilt or get their packaging damaged depend on it. while stored in your facility. The sums add up – big time. 7 DO YOU HAVE A HUMIDITY PROBLEM? HUMIDITY CAN’T BE SEEN THESE PROBLEMS It can be difficult to know how much humidity is Nevertheless, humidity – and in particular the tangible actually present inside your cold store set-up. The results of uncontrolled humidity – can have big USUALLY NEED DEALING moisture is in the air, and you can’t actually see effects on a wide range of your operating costs. The humidity – just the tell-tale signs that it’s there. problem is that the links between cause and effect WITH BECAUSE: aren’t always obvious. > They give rise to additional costs that burden your BUT THE SYMPTOMS CAN budgets and affect profit margins THE TELL-TALE SYMPTOMS ARE THINGS LIKE: > They represent damage to stored goods and their packaging – which is bad for business and soon means dissatisfied customers > They give rise to work environment issues and conditions that are dangerous for anyone working Ice forming on fixtures and Water and ice accumulating Ice and ice pickles forming in or passing through the facility equipment, and blocking and causing problems on cold surfaces evaporators > They represent lack of control over operating conditions, thus affecting quality assurance and good practice in cold store management. Stored goods getting wet Mist forming in the air and damaged 8 9 ICE BUILD-UP IN A FROZEN GOODS HOW BIG IS THE PROBLEM? STORAGE FACILITY 100 Ice and condensation will always form to some The deciding factor usually lies in the balance -18°C 80 Φ=90% degree in any refrigerated or freezer storage facility between cost and benefit. When ice and condensation – you can’t escape the basic laws of physics. start making a significant impact on your operating costs, customer retention statistics or work safety 60 Ice build-up in a frozen goods Φ=50% The question is whether there is an acceptable record, it’s probably time to do something about it. storage facility as a result of level? At what point you should you actually 40 different air conditions. ] (1 litre = 0.2 kg) take any measures needed to limit or control any /h L 2 [ =30% undesirable levels of humidity that give rise to such Moisture entry is through a 6m 20 Φ ice and condensation? When does an irritant and a opening with doors that open ICE bugbear become an unacceptable cost? for 10 seconds, 10 times an hour 0 (on average). 0 5 10 15 20 25 EXTERNAL DRY TEMPERATURE (˚C) CAN YOU REALLY EXAMPLE OF MOISTURE LOAD FROM CONTROL HUMIDITY? DOOR OPENINGS TYPICAL COLD STORE The formation of ice and condensation is pretty However, the basic laws of physics mean that ice DOORWAY FROST ACCUMULATION much inevitable in any refrigerated or freezer storage and condensation can, in fact, be kept from forming facility – and probably has been ever since mankind by controlling and adjusting the conditions present How the air moves when a door is opened ICE CRYSTALS opened the door on industrial refrigeration. in the air. between a warm and a cold room. The layman perception is that it’s a persistent, In many existing set-ups, the only realistic, reliable nagging problem that seems unavoidable. way to do this is by adsorption dehumidification – applied in the appropriate manner. 5 C 80% RH LOADING DOCK WARM INFLOW - 25 C 90% RH WHAT DO HUMIDITY PROBLEMS FREEZER COST YOU? COLD OUTFLOW MIST ICE ON FLOOR What do humidity problems cost you? What will it Cotes experts have solid practical experience with cost to make changes in your cold store set-up, and helping customers determine the exact costs and to introduce humidity management? Will it actually benefits associated with humidity and its control. A door 3 metres high and 2 metres wide is opened The moisture load from such a door (disregarding pay to make any changes/improvements? Please contact us to hear more. 10 times per hour for 10 seconds. The external draughts during opening) is then around 2.5 climate conditions are 8 °C and 80% relative kg/hour. humidity. The conditions inside the cold storage facility are -18 °C and T_dew = -20 °C). A cold storage facility with four such doors will then be exposed to the ingress of 10 kg moisture/hour. 10 11 PRACTICAL ISSUES COMMON IN COLD STORE SET-UPS SOURCES OF HUMIDITY Ice and condensation stem from air laden with undesirable moisture, undergoing a phase change when certain specific conditions arise. The most common sources of such moisture-laden air are: > Points of entry where doors/barriers are open for too long and/or close too slowly > Inappropriately sealed doors/openings in the outer structure > Ineffective sluices and other areas where goods are “in transition” > The goods stored within the facility > People and vehicles present within the facility > Pressure equaliser set-ups. 12 13 WHERE ICE AND CONDENSATION FORM FLOORS WALLS OTHER TECHNICAL STORED GOODS EQUIPMENT CEILINGS AROUND EVAPORATORS UNFORESEEN PLACES 14 15 A PLETHORA OF PRACTICAL PROBLEMS Unwanted ice and condensation can cause a wide range of costly problems in cold store facilities. In consultation with industry experts, Cotes specialists have identified the following as the most serious and the most widespread problems. REDUCED PRODUCT SAFETY ISSUES REDUCED PRODUCT POOR WORKING WASTED MAN-HOURS HIGHER ENERGY QUALITY HANDLING EFFICIENCY ENVIRONMENT AND REDUCED BILLS AND CUSTOMER PRODUCTIVITY SATISFACTION HOWEVER, IN GENERAL THE SITUATION IS AS FOLLOWS: Melting ice or pooled Ice and condensation result in Ice and condensation can result Formation of ice makes it difficult Once formed, ice needs to be Ice and condensation in cold condensation can damage the slippery floors in many small hindrances to to close doors and other openings removed and condensation needs stores need to be removed packaging of goods in the cold b Staff can slip/fall, forklift effective, error-free transport, properly to be dried up before it freezes b Additional energy store facility trucks, pallet movers and other stacking and logistics b Draughts, additional ingress to ice consumption for defrosting b Greater waste, reduced profit equipment can skid and cause b Reduced product handling of moisture-laden air, etc. b Constant need to use of fixtures, fittings and margins and negative effect on accidents and injuries as well efficiency and higher costs manpower for non-productive refrigeration equipment customer relations as damaging goods, equipment Staff experience a cold working purposes and fixtures Ice can form on the barcodes on environment with high levels of Evaporators work inefficiently Undesirable moisture can result in products, packaging and pallets humidity as colder/more uncom- Ice and condensation result when iced up both damage and contamination Humidity in the air can cause b Product IDs/labels falling fortable than an environment with in slower movement and more b Additional energy of goods in the facility mist and reduced visibility off or cannot be read/scanned the same temperatures but low accidents consumption b Health risks, greater waste, b Accidents affecting staff, effectively, resulting in humidity b Lower productivity and higher reduced profit margins and vehicles, goods, equipment and non-productive time and b Lower staff morale, higher manpower costs for treatment/ In some cold stores floors are negative effect on customer fixtures workflow inefficiencies margins absenteeism statistics compensation/insurance, etc.