Considerations When Purchasing a -86°C Laboratory Type Ultra-Low Freezer

Operation in High Ambient Temperatures

The ambient temperature of the area where the device will operate is one of the most important factors to consider. Additionally, the heat emitted by the device during operation should also be taken into account.
Many -86°C freezers on the market are not suitable for operation in high ambient temperatures like +30°C. Therefore, when choosing a -86°C freezer, selecting devices capable of operating at +30°C or higher will be beneficial for you.

Capacity

-86°C freezers come with different capacity options. While determining the capacity based on your needs, remember that the device should not be packed full. The circulation of cold air inside is important for the safety of your samples. Additionally, an overfilled device will struggle to cool samples or will have a shorter lifespan.

Type/Variety

-86°C freezers can be chest-type or upright. The advantage of chest-type models is that since cold air sinks downward, they experience less temperature loss after door openings compared to upright types. However, their biggest disadvantage is that they occupy more space. Therefore, upright models are generally preferred.

Internal Temperature Distribution

The internal temperature displayed on the device's screen comes from a single point temperature sensor. However, different points inside the device won't show the same temperature. Having minimal temperature variation between all points (good internal temperature distribution) is crucial for sample safety. Samples stored in devices with good temperature distribution maintain higher viability rates when thawed.

Energy Consumption

Especially older generation -86°C freezers consume very high energy (20kWh or more). With advancing compressor technology, cooling gases, and improved insulation, energy consumption has been reduced by up to 70%. Energy consumption varies according to capacity.
A device consuming 20 kWh daily costs 14.2 TL per day, 426 TL per month, and 5112 TL annually. A device consuming 8 kWh daily costs 5.68 TL per day, 170.4 TL per month, and 2044.8 TL annually. (1 kWh electricity including residential taxes: 0.71 TL)

Cooling Gases Used

Until recently, HFC (hydrofluorocarbon) and mixed gases were used in all brands. However, the industry has now begun transitioning to HC (hydrocarbon) gases. The advantages of HC gases are their very low GWP (global warming potential) values and their contribution to lower energy consumption.

Heat Emission to Environment

-86°C freezers emit considerable heat to their surroundings during operation. Lower heat emission results in less increase in ambient temperature. Consequently, the device works less hard, consumes less electricity, and has a longer lifespan. Additionally, lower ambient temperatures eliminate or reduce the need for air conditioning.

Compressor

Currently, there are devices on the market with both fixed-speed and variable-speed compressors. Variable-speed compressors can operate slowly or quickly according to current needs. The advantages of devices with variable-speed compressors can be summarized as: much lower energy consumption, lower heat emission, and lower noise levels.

Noise Level

-86°C freezers are noisy devices. Most users complain about this issue. Therefore, considering noise level is an important factor not to be overlooked when choosing a -86°C freezer.

Insulation

Especially during power outages, having a long temperature rise time inside is crucial for sample safety. In well-insulated devices, the internal temperature takes longer to reach critical thresholds during power outages. Some brands' documentation may include test data on this subject. When comparing these test data, attention should be paid to whether the test was conducted with the device empty or full.
It's normal for test values to be longer when the device is full. Additionally, well-insulated devices consume less energy and have better temperature homogeneity. While thicker insulation provides better insulation, it also increases the device's footprint. Today, some brands use VIP (vacuum insulation panels) to reduce thickness without compromising insulation quality, aiming for devices that occupy less space.