Advantages Of Using Hydrocarbon, Green, Refrigerants In Laboratory Coolers / Freezers

Currently used refrigerants in laboratory freezers and/or coolers are mostly of the fluorocarbon type. These refrigerants do contribute, when emitted to the atmosphere, to the greenhouse effect. Therefore, these chemical refrigerants are included in the Kyoto Protocol that is linked to the United Nations Framework Convention on Climate Change. It is clear that there is pressure on the use or emission of these refrigerants, which means that limitations can be expected in future. This may pose problems for existing freezers at the end of life or during servicing. As an alternative it is possible to apply hydrocarbon refrigerants, which are generally excellent refrigerants with favourable properties and contribute very little to global warming. If well designed, in many cases an energy saving can be expected which reduces the environmental impact further, by reducing the CO2

emission related to the electricity generation needed to drive the product. The drawback however, is that hydrocarbon refrigerants are flammable and adequate measures are needed to design safe products. Experience in other application areas, such as domestic and commercial refrigeration, has shown that this is well feasible.

INTRODUCTION

Laboratory freezers and/or coolers generally apply a vapour compression technique to generate a cold environment for storage of various goods. The basic circuit behind this cooling process always contains a compressor, condenser and evaporator (see Figure 1). In this circuit heat is released from the condenser to the ambient and heat is absorbed by the evaporator, which is typically placed inside the cabinet to be cooled. The compressor is needed to circulate a refrigerant and to raise the refrigerant pressure from the evaporator to the condenser level.