7 Things You Need to Consider When Purchasing an Ultra-Low Freezer
What are the Different Types of Ultra-Low Freezers?
When it comes to purchasing an ultra-low laboratory freezer, there's more to consider than just the price tag. When selecting an ultra-low freezer, it's imperative to choose one that suits your research applications and facility specifications. The three most common types of ultra-low freezers (benchtop, chest, and upright) all differ in size, efficiency, accessibility, and temperature range.
Ultra-Low Freezer Benchtop/Undercounter Models
The smallest type of ultra-low freezer is the benchtop/undercounter model. As the name implies, these devices are meant for use on top of a lab bench or underneath a countertop. Benchtop/undercounter models are ideal for facilities with less space and fewer capacity needs and because of their small size, they’re also convenient for moving samples around frequently without taking them out of their frozen environment.
Upright Ultra-Low Freezer Models
The most common ultra-low freezer model is the upright ULT freezer. Upright ultra-low freezers are larger than benchtop units and can therefore hold more samples. They’re also more convenient in terms of accessibility compared to their chest freezer counterparts. Another additional benefit of upright freezers is that many modern upright ULT freezers have adjustable or removable shelves to house samples of varying sizes. However, compared to chest freezers they are slightly less efficient because every time the door opens, cold air is more likely to escape due to the tendency of colder air to flow downwards. Therefore, samples that require long-term storage may be more compatible with a chest freezer.
Ultra-Low Chest Freezers
Ultra-low chest freezers are slightly more efficient and typically last longer than upright freezers. This is because chest freezers require minimal use of the compressor and are often faster at reaching temperature set points. However, they are less common than upright models because of floor space limitations and ease of access to stored samples.
Ultra-Low Walk-In Freezer Rooms
The least common ultra-low freezer model is the walk-in ultra-low freezer room. Because of the size, cost, and employee safety concerns, they’re not nearly as common as the previously aforementioned ULT models. However, for unique facilities needing much larger ultra-low storage capacities, a walk-in ultra-low freezer may be the best option. One possible reason for choosing a walk-in ultra-low freezer over traditional models is the potential for energy, maintenance, and space saving potential. This is because one larger walk-in freezer room can be more cost and energy effective than powering dozens of ultra-low freezers, especially for facilities with expansive sample archives that don’t need to be moved around often. Even so, the employee safety and logistical concerns make ULT walk-in freezers relatively rare.
What Additional Factors Do I Need to Consider?
1. Size and Capacity
The capacity of the ULT freezer is an important factor to consider because it impacts the total amount of biological materials that can be stored. This capacity is typically expressed in liters or cubic feet, and it is important to ensure that your chosen model meets or exceeds your needs. The size of your lab will also impact which type of ULT freezers you should consider. If you are working in a small lab, then an upright model or benchtop freezer may be more convenient than a horizontal chest freezer.
Another thing to keep in mind is proper ventilation for your unit. Conventional ULT freezers need several inches of adequate ventilation around the top, back, and sides of the unit for proper air circulation.
Reliable sample storage is the priority when it comes to a cold storage decision because your lab research depends on having high-quality, properly stored samples. Most ULT freezers have a set temperature differential rate with indicates how from the set temperature the actual temperature may deviate to. When purchasing a ULT freezer, be sure to do your research on the manufacturer and model’s reliability rate. Brands like American Biotech Society and Thermo-Fisher have been around for 25+ years and have a proven track record of reliability. Additionally, make sure your distributor is experienced in the field and can answer any questions about the model and your intended uses.
You also need to consider power and voltage requirements. Does your lab have the appropriate electrical resources in place, or do you need a professional to come in and install what you need? Larger ULT freezers typically require higher voltages compared to smaller models. If the voltage is too high, it can lead to overheating. On the other hand, if the voltage is too low, there may be sparks or electrical arcs as current flows through components. In both scenarios, improper voltage setup can shorten the life of your ultra-low freezer.
As a result of the intensive fan-cooling needed, ULT freezers can be a significant source of noise in the lab. If you're concerned about background noise or simply want to make sure that your freezer doesn't disturb your lab mates, this is something you'll need to consider before making a purchase. Luckily, many energy-efficient models are also less noisy compared to their older counterparts. In fact, many modern ULTs freezers produce less than 40 decibels of sound and can be kept in the lab without making a disturbance.
5. User Interface and Monitoring
The ability to monitor your freezer remotely is especially useful if you plan on using it to store sensitive samples or products that require frequent temperature adjustment. Modern ULT freezers come equipped with a variety of options for remote monitoring and control, meaning you can keep tabs on your samples at any time, from anywhere. The user interface is also an important factor to consider. Is the equipment easy and intuitive for lab professionals to use or will it require additional training? A particularly difficult user interface can also cause delays in research for troubleshooting.
With rising energy costs and increasing awareness of the carbon footprints of research labs, lab equipment manufacturers are also improving the overall sustainability of their products. Conventional ultra-low lab freezers use approximately 20 kWh of energy per day, about as much as an entire average US household. On the other hand, ENERGY STAR certified ultra-low freezers use a more efficient compressor, microprocessor controllers, and environmentally friendly refrigerants which make them much more energy efficient. Some newer compressors are even equipped with learning algorithms to learn from past usage patterns, adjust their operations accordingly, and optimize energy consumption.
7. Warranty Options
Many ultra-low freezer models come with either a manufacturer or distributor warranty. For example, Nuaire ultra-low freezers come with a 3-year parts & labor warranty and Thermo-Fisher includes a 2-year parts & labor warranty with their ULT freezers. Some suppliers and manufacturers also offer extended warranties which can be a beneficial investment if your budget allows for it.