Maintaining a Laboratory Refrigerator or Freezer

By Aimee O'Driscoll, 13 June 2018

All good things must come to an end, including the life of your laboratory refrigerator or freezer. But obviously you want that to be later rather than sooner. Under certain conditions, such as under heavy load, in a harsh environment, or having been poorly maintained, your refrigerator or freezer might not work as well or last as long as it could otherwise.

Thankfully, there are some steps you can take to ensure it runs efficiently for as long as possible. If your refrigerator or freezer isn’t working properly, a likely cause is the compressor. As such, to increase the useful life of a laboratory refrigerator or freezer, you’ll need to take extra care of that compressor. This means avoiding putting unnecessary additional stress on it.

Some of the major things you can do are:

  1. Avoid opening and closing the door unnecessarily frequently
  2. Maintain an environment that’s cool and not too humid
  3. Keep the machine and surrounding area clean
  4. Replace worn out gaskets when necessary
  5. Remove frost in freezers

Let’s look at these in more detail.

1. Avoid Opening and Closing the Door Frequently

This is a simple tip that many people forget. Every time you open or close the door, you’re letting in warm air (and humidity) and increasing the heat load on the compressor. Additionally, keeping the door open for longer than it needs to be will increase this load.

2. Maintain an Environment That’s Cool and Not Too Humid

A warm environment again has the effect of increasing the heat load on the compressor. What’s more, high humidity (above 50%) can negatively impact the performance of the refrigerator or freezer. When doors are opened, humidity in the air enters and forms condensation. This must be removed, resulting in more work for the machine. In freezers, it might mean the defrost cycle has to be run more regularly.

3. Keep the Machine and Surrounding Area Clean

It’s easy for dust and dirt to build up on the condenser coils. This insulates the coils making heat removal less effective and making the compressor work harder to maintain temperature. All this extra work is going to reduce its lifespan.

It’s recommended that cleaning of the areas around the condenser coils and compressor be carried out at least twice annually, or more often for dust-prone environments.

On that note, a clean environment is important too, to prevent the buildup of dust in the first place. Additionally, keeping the area around the appliance as clear as possible ensures air can circulate properly.

4. Replace Worn Out Door Gaskets When Necessary

Door gaskets undergo wear and tear and should be checked regularly and replaced if needed. Aside from a visual inspection for wear and tear, you can conduct a “dollar bill test.”

In this test, you close the door on a bill or piece of paper, then pull it out. If there is no resistance, then you likely have a compromised seal. The entire seal should be checked in this manner, so it could be a tedious process for a larger machine. Alternatively, if you have one at hand, a laser thermometer will offer a quick way to check for leaks.

5. Remove Frost in Freezers

Just as in home freezers, frost can build up in laboratory freezers over time. This buildup acts like insulation and can hamper the ability of the compressor to move away unwanted heat. This means the compressor will run for longer, lowering its lifespan and using more energy.

Some freezers will have an indicator to tell you when you need to remove frost. But in general, if you can’t see the wall of the freezer or closing the door is difficult, it’s past time to deal with it. Indeed, representatives from So-Low Environmental Equipment Co. recommend defrosting when about half an inch of ice has built up on the walls of the chamber. Depending on the environment and usage, this could be as often as once a month or as little as twice a year.

They also noted that it might be tempting to scrape away the ice instead of defrosting the freezer. While this is possible, it can be counterproductive. Manually scraping the ice would involve keeping the door open, allowing more ambient moisture to enter the unit and causing further frost buildup. As such, fully defrosting the freezer is a better option.


Keeping up with regular maintenance of you laboratory refrigerator or freezer should result in it staying in good working condition for longer. This helps you in terms of having a machine you can rely on. Plus, you’ll save money on repairs or replacements.