Merck Sante, based in the French city of Orleans, manufactures and distributes pharmaceutical products. Their main warehouse is required to operate under the conditions of ‘controlled room temperature’ which for their range of products is less than 25°C.
Eighteen down discharge EcoCooling ECP16000 evaporative coolers were installed feeding high level plenum chambers.
These positively pressurise the warehouse and air is extracted using automatic vents.
The coolers are all linked to a common control panel.
Temperature is monitored at three levels in the warehouse and the coolers controlled accordingly. A humidistat ensures that the internal humidity does not exceed 85%.
All coolers are linked to the fire alarm system for automatic shutdown.
The principle of mean kinetic temperature (MKT) can be applied to pharmaceutical storage using the Arrhenius Equation.
Tk is the MKT, ΔH is the activation energy, R is the universal gas constant, T is the temperature in degrees K (i.e. °C + 273.1), n is the total number of (equal) time periods over which data are collected, and e is the natural log base.
The graph shows that on a 40°C day the ambient MKT is 33°C. The output of an evaporative cooler in these conditions gives a MKT of 25°C which meets the storage criteria for this range of pharmaceutical products.