Lab Freezer Selection and Failure Prevention

Freezers are an integral piece of laboratory equipment, keeping your samples and other laboratory materials at the right temperature in a secure environment. With so much at risk, choosing the right freezer for your laboratory is vital. Furthermore, understanding how to reduce the risk of freezer failure, and what to do if the worst happens, are crucial to ensuring your samples and valuable reagents are protected.

“Instrument discovery questions are critical to the success of any laboratory instrument purchase, and cold storage products are no different,” explains Dean Rainbolt, Technical Applications Manager, Controlled Temperature Technologies at Thermo Fisher Scientific. “Asking a few questions before purchase will ensure that you properly match the correct instrument for the application needed.”

Desired temperature range

When selecting a freezer, the most central of those questions is the desired temperature you need to reach, which is determined by what you are looking to store. Different freezer types offer different temperature ranges, so it is important to understand your freezer usage requirements in order to select the most appropriate model.

General purpose, low temperature freezers usually reach between -20°C to -45°C, and are ideal for storing enzymes, reagents, and numerous cell types, in addition to biological samples and vaccines. Ultra-low temperature freezers have operating temperatures from -45°C to -90°C, and are mainly used for long-term storage, as well as for storing drugs, tissue samples, viruses, and bacteria. Cryogenic freezers offer the lowest temperature ranges—reaching down to -150°C. They are utilized for indefinite storage or the preservation of sample integrity.

Capacity and location

Another important consideration is the size of your freezer—with the right capacity depending on the number of samples you need to store. In addition to being realistic about how much you will regularly store, plan ahead for additional qualified storage space in the event that samples need to be temporarily relocated.

The available footprint in your lab can also have an impact on the size of the freezer you purchase, as well as influencing if you choose an upright or chest configuration. Before you select your final model, make sure its dimensions will fit in your designated space as well as through any doors and entry points.

Do you need any additional or special features?

”Connectivity is a game changer regarding sample safety,” adds Rainbolt, so investigating freezers with a remote monitoring system is a worthwhile consideration. In addition to alerting you to freezer failure at any time of the day or night, comprehensive monitoring systems can also predict failure before it occurs—identifying issues before they become an emergency.

Purchasing a model with an emergency cooling system is also useful to consider; especially if your laboratory is prone to power outages, or your samples are particularly valuable. Other features you may want to consider include automatic defrosting options, easy-to-use system interfaces, and environmentally friendly refrigerants.

What causes freezer failure

Once you have purchased your freezer, ensuring its peak performance is key. There are many reasons why a freezer might fail, but as Damian Kurtz, Customer Support at NuAire, explains “the most common freezer failures occur due to lack of proper maintenance, or bad practices.” One particularly egregious practice is not periodically defrosting your unit, as excessive ice build-up can affect freezer cooling and cause issues with door seals and latches. According to Kurtz, “things like dirty condenser coils, excessive frost on the evaporator coils, or a damaged door gasket, are fully preventable with regular visual checks and a good preventive maintenance plan.”

Other causes of freezer failure are generally the result of people using the “equipment improperly” warns Kurtz. The door being opened too frequently or left open longer than needed can impact operation—so all laboratory staff should be properly trained in freezer usage according to manufacturers’ guidelines.

What to do in the event of failure

If, despite your best efforts, the worst happens, and your freezer stops working—what do you do? First and foremost, do not open the door! As Bettina Grochulla, Product Communication at Eppendorf, explains, the most important thing is to “Keep calm, you have several hours after the first alarm until the temperature inside the freezer is at critical level”—if you keep the door closed.

To troubleshoot a malfunctioning or non-functioning freezer, first, check the power supply and try to re-boot the freezer. If this does not work, then sample relocation will be needed. Laboratories should have a sample evacuation plan already in place explains Grochulla, but if you don’t—take the time to make a plan before starting. “If you are lucky, there is a back-up freezer” in your building designated for samples in the event of failure, Grochulla says hopefully, but for many laboratories where equipment space is at a premium, this is not always possible. In this case, you need to locate available space in other freezers, and you may need to prioritize materials for relocation.

Laboratory freezers keep your most valuable samples safe, so ensuring their peak performance is important. Regular freezer maintenance and proper use can help prevent freezer failure, while having an evacuation strategy in place helps prevent chaos if the worst occurs. The role of remote monitoring systems is also becoming critical—in addition to providing piece of mind, the ability of systems to predict freezer failure before it occurs means that connectivity should now be a central consideration when making a purchase.