The energy efficiency of laboratory refrigerators and incubators can be improved immediately, by installing EC evaporator fan motors and LED door lights instead of the standard (shaded pole) fan motors and T8 or T5 fluorescent lights. For example, replacing 2 F32T8′s and one 9 watt 1550 rpm standard fan motor on a two-door chamber saves about 1.6 kw of power per day. If you are in the market for new equipment, specify these energy saving devices when you ask for a quotation.
Look for chambers with bottom mounted evaporative compressors, instead of top mounted ones. Bottom mounted evaporative compressors are not only quieter, but they use the heat of the compressor to evaporate condensate collected on the refrigeration coils. Top mounted compressors cannot use gravity to bring the collected condensate to them – they have to pump the water up from the refrigeration coils inside the chamber, or use a condensate evaporator on the rear wall to heat the water until it disappears- which wastes energy.
If you plan to keep your chamber temperature setting at 4C (40F) or higher, you will not need an automatic defrost cycle to heat the refrigeration coils to prevent them from icing. The coils will defrost naturally, whenever the compressor turns off. If the refrigerator or refrigerated incubator comes with this feature, request that it be de-activated. Or buy a chamber with no active defrost cycle – why pay for it?
The best advice with regard to energy efficiency in temperature controlled chambers is to keep them filled, while allowing conditioned air to flow around the product, per the manafacturer’s instructions. Creating a large thermal load will improve the temperature uniformity and reduce the number of cooling or heating cycles needed. If your product doesn’t add much thermal mass to the large open space that is a refrigerator or incubator, place half-liter bottles of spring water along the side walls to improve the chamber’s energy performance and to even out temperature variation within the chamber.