Removing frost on a regular basis is important in taking care of your lab fridge or freezer as it will affect uniformity, energy consumption, and possibly product viability long-term. Having the correct voltage and regularly cleaning filters are also crucial to proper operation. In addition, users should avoid storing things on top of the fridge or freezer, otherwise air won’t be able to properly circulate and the unit will overheat.
How does the type of sample being stored influence which type of cold storage unit is ideal?
The type of sample being stored will directly affect the type of freezer required. General purpose freezers with a range of -20°C to -30°C are ideal for enzymes and biochemical reagents. Low temperature freezers in the range of -30°C to -45°C are suitable for biological samples, vaccines, and blood products. Ultra-low temperature freezers in the range of -45°C to -86°C are used for drugs, viruses, bacteria, cell preparations, tissue samples, and long term storage. Knowing your sample type and applications beforehand will help streamline the purchase process.
How will the energy requirements of a ULT affect the overhead costs of the laboratory?
A commonly overlooked factor in the purchase of a ULT is the energy needed to operate it. ULTs must work relentlessly in order to maintain their extremely low temperatures, and in some cases a conventional style ULT can consume up to as much energy as the average American household. Over time, innovations in compressor technology, cabinet design, and insulation have ushered in an era of energy efficient ULTs which can help alleviate the energy draw—and as a result—operation costs.
How do samples which are volatile or explosive affect the type of cold storage required?
For samples and reagents which are considered flammable or hazardous (typically found in Class 1, Division 1, Group C, and Group D environments), an explosion proof freezer should be utilized. These are designed to protect lab workers, the environment, and stored materials. They include a spark-free interior and exterior, manual defrost, plug-free cords, and are CFC/HCFC free to prevent ignition of flammable or volatile materials.
