Refrigerators for Laboratory Applications

Several different types of laboratory refrigerators
Image courtesy Powers Scientific

Many laboratories have a need for refrigerated space. The requirements for that space vary widely enough to support a very broad range of refrigerated cabinets, providing variants and optional features that meet every need. Refrigerators tend to last for a long time, so it's practical to make a considered decision when procuring one for the lab. Here are some items to include when selecting a new lab refrigerator.

• Materials to be Stored: Certain flammable materials requiring cold storage must be kept in a refrigerator specifically designed and rated for the storage of those materials. Less hazardous materials can be accommodated by a wider variety of choices. 
• Storage Temperature: Determine the most sensitive content for the proposed refrigerator. What are the highest and lowest temperatures providing suitable storage conditions? Lab refrigerators are generally not precision control chambers. Know the requirements of your contents and the capabilities of the refrigerator. Make sure they are compatible.
• Controls and Monitoring: What are your needs for control, display, and monitoring of cabinet temperature? Is a dial thermometer a sufficient temperature indicator, or is a digital display more appropriate? There are many options available. Think about how temperature should be monitored and out of range occurrences handled. Keep in mind that electronic controls will not function during a power failure without a backup power source. Maintaining documentation of chamber temperature under all conditions may require inclusion of battery backup for data logging and alarm devices.
• Cabinet Size: Lab refrigerators are available in sizes ranging from a few cubic feet to units as large as a grocery store display line. Take the time to make a layout of your storage needs, everything that will go in the refrigerator. This will help in determining the best size for your application. 
• Doors: The refrigerator doors are the user interface for the unit. They are what you touch every time the refrigerator is accessed. Make sure the selected doors meet the application needs for interior visibility, security, and ease of access. Also take into account the space where the refrigerator will be installed. Sliding doors do not encroach on the surrounding space, as a hinged door would.
• Heat Rejection: An often overlooked aspect of lab refrigerator operation is where the heat removed from the chamber interior will go. A refrigeration system is a heat transfer machine, taking heat from the chamber air and rejecting it from the condenser. The condenser is usually air cooled, resulting in that heat being released into the space where the refrigerator is installed. There must be an identified path for that rejected heat to be further transferred out of the installation space, otherwise the space will increase in temperature until the refrigeration unit fails. If an assessment of the proposed installation space for the refrigerator fails to identify sufficient ventilation, there are several refrigeration system schemes that can be substituted for the self-contained condenser most often seen on lab refrigerators.
• Accessories: There are more available options and accessories for laboratory refrigerators than could be included here. Users should describe to potential vendors the manner in which the refrigerator will be used. Refrigerators employed as simple cold storage units will have a simple set of requirements. Those used as part of a process may have very special configuration requirements. 
• Transit: Some lab refrigerators are quite large. Of course, you should measure the space where the unit is to be installed, making sure there is a fit. Do not forget to verify that the equipment must pass through all the doors, hallways, elevators, and other spaces that make up the path from delivery point to installation point.

There is much more detail that may be involved in making the best selection. Enlisting the assistance of a laboratory equipment specialist will help speed you through the selection process and create a successful purchase, delivery, and installation plan.