INCORPORATING COLD CHAIN |
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It is not clear if this was scientifically proven or just what was mostly available and found to be suitable . However , it was also noted that it is generally accepted that higher storage temperatures , if held relatively stable , can be quite acceptable for extended periods .
Pandell ( 1996 ) published a research paper that concluded that if the storage temperature was increased from 13 ° C to 23 ° C , the ageing process of wine quickened by a factor of between 2 and 8 , depending on the wine . His conclusions indicate that the lower the temperature , the longer wine takes to age , but given steady temperature and acceptable conditions , moderately cool temperatures are acceptable .
Experience in the industry has also found that not only temperature , but also humidity is a concern where wine is aged in barrels . Low humidity causes excessive loss of wine through evaporation , leading to increased costs of barrel handling required for topping up .
In a climate such as South Africa ’ s , where natural conditions will not allow adequate temperature control for barrel storage , some form of mechanical air conditioning needs to be applied to maintain the
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DESIGNING A CONTROLLED ENVIRONMENT
Bosman has gained a reputation for always seeking out the latest and greatest technology — not only in their agricultural practises but also their winemaking . Petrus Bosman is experimenting with an entire range of innovative things , using energyefficient equipment throughout the farm .
As such , he has been keen to try out a new type of barrel they saw in Spain : an alternative to the traditional wooden oak barrel commonly used throughout the world . These 1 500l vessels * are made from plastic and are square shaped , claiming various benefits and cost savings .
To properly conduct this new ‘ experiment ’, he needed a controlled environment in terms of temperature and humidity for the various types of wines he had in these imported new plastic ‘ barrels ’. He contacted Marius Louw of Louwco Cooling Solutions in Wellington , with whom he has had a long-standing relationship , to assist with a cooling solution for this new store . ( The room also houses pallets of bottled wine , ready to be shipped out to various areas .)
There was a room requirement of 20 ° C inside with a minimum humidity of 70 % ( with 34 ° C dry bulb and 19 ° C wet bulb
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COMPARING THE OPTIONS
Seeley International has spent a lot of time and research working on solutions tailor-made for the wine industry . As such , they did a study comparing three cooling options : direct evaporative cooling ; refrigerated air conditioning ; and indirect evaporative cooling .
1 . Direct evaporative cooling Traditionally used in hot dry climates and characterised by :
• Limited temperature control of the space , typically a minimum of 25 ° C to 27 ° C .
• Increased humidity in the conditioned space .
• 100 % outside air is used to cool the space .
• Cooling performance is adversely affected by ambient conditions of high relative humidity ( RH ).
• Modest capital cost of installation .
• Low power requirements .
• Low cost of operation .
2 . Refrigerated air conditioning Applicable for most climates and characterised by :
• Precise temperature and humidity control is possible .
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conditioned space .
• Closed cooling — cools the internal air , and draws little or no outside air .
• Operates in all climates if designed correctly .
• High capital cost .
• High power requirements .
• High operating cost .
3 . Indirect evaporative cooling Very effective in hot climates that are dry and those that are moderately humid and characterised by :
• Much lower temperature of supply than a direct evaporative cooler .
• Good temperature control available .
• No additional moisture added to or removed from the conditioned space .
• 100 % outside air is used to cool the space .
• Usable in moderately humid climates .
• Moderate capital cost .
• Low power requirements .
• Low operating cost .
BOSMAN ’ S ( COST-EFFECTIVE ) SOLUTION
Louw , who previously used Seeley ’ s
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desirable environmental conditions . |
temperatures outdoors ). |
• Removes moisture from the |
products in agricultural applications |
Inside Bosman ’ s new ‘ barrel ’ store . |