Question about how to use A chest freezer like a refrigerator often appears among owners of commercial outlets, farmers, or simply prudent householders who are faced with a breakdown of the main refrigeration chamber or a sudden influx of guests. Chest freezer initially designed to maintain low temperatures, usually from -18°C and below, which makes it ideal for freezing, but unsuitable for short-term storage of fresh foods that require refrigeration.
However, it is technically possible to reprogram the device to operate in refrigerator mode if you set the thermostat correctly and organize the internal space. Conversion requires an understanding of the physics of the compressor and the features of the distribution of cold air in a closed volume. In this article we will analyze in detail all the nuances of such conversion.
The main difficulty is that the standard settings do not allow raising the temperature above the freezing point without intervention in the control system. Without installing an external thermostat or replacing the internal sensor, most household chests will not be able to stably maintain a temperature of +2...+5°C. Let's look at how to bypass these restrictions safely.
Fundamental differences between operating modes
Before starting modification, it is necessary to clearly understand the difference between operating modes. Freezer works cyclically, cooling the air to extremely low values, after which the compressor is turned off for a long time period. Refrigerator, on the contrary, must maintain the temperature in a narrow range just above zero, turning on more often, but for shorter periods of time.
The main problem lies in hysteresis thermostat. In a freezer, the difference between turning on and off can be 10-15 degrees, which is too much for refrigeration mode. If you simply set the temperature to -2°C, the products may either freeze or heat up to a dangerous temperature of +8°C.
In addition, chests often lack forced air circulation (No Frost), and cold air, being heavier than warm air, accumulates at the bottom. This creates a risk of local hypothermia products lying on the bottom, while the temperature at the lid can be significantly higher.
- ❄️ The freezer freezes food “tightly”, destroying the cellular structure during defrosting.
- 🌡️ The refrigerator maintains freshness by slowing down the growth of bacteria without freezing.
- 🔄 Compressor operating cycles in different modes differ radically in duration.
⚠️ Attention: Trying to store fresh vegetables or dairy products at temperatures below 0°C will cause them to spoil and loss of taste after thawing.
Necessary equipment for conversion
To successfully use a chest freezer as a refrigerator, you will need additional equipment. The standard functionality of the control panel is usually not enough for precise adjustments in the positive temperature range. The main element will be external thermostat.
You will need a device that will break the compressor power supply circuit when the specified upper temperature limit is reached. Such devices are often used in incubators or terrariums, but are also suitable for our task. It is also recommended to purchase a separate thermometer to monitor real indicators inside the chamber, since the built-in sensor can lie.
It is important to choose a thermostat with a remote sensor, which can be mounted in the center of the chest, away from the walls and bottom. This will ensure that the average air temperature is read, and not the temperature at the evaporator. Measurement accuracy in this case, it is critical for product safety.
- 🔌 External thermostat with a setting range from -50°C to +40°C.
- 🌡️ Remote temperature sensor for calibrating readings.
- 🔧 Tools for safely attaching wires and sensors inside the chest.
You should not try to regulate the temperature only by changing the position of the internal thermostat handle, if it is mechanical. The scale on such handles often does not have a graduation in positive values, and the position “0” or “1” can mean either +5°C or -10°C depending on the specific model Danfoss or Embraco.
Step-by-step instructions for setting the temperature
The setup process requires consistency and caution. First you need to completely defrost the chest and let it warm up to room temperature. This is important for correct initial calibration of thermostat.
Connect the external thermostat to the network and to the power outlet of the chest itself. Set the desired temperature, for example +4°C. Place the remote sensor of the external regulator in the center of the chest, securing it at medium height. Now plug the chest into the network through the thermostat.
The internal thermostat of the chest (if it is mechanical) should be turned to minimum cooling or left in the position corresponding to the highest temperature that it can provide. The external regulator will take on the role of the main controller, turning off the power to the entire chest when it becomes too cold inside.
☑️ Checking the temperature setting
Monitoring is necessary for the first day. Record readings every 2-3 hours to understand the amplitude of fluctuations. If the temperature drops below +1°C, increase the target value on the external controller. If it rises above +7°C, lower it.
⚠️ Attention: Do not load the stall with food right away. First, stabilize the temperature with an empty chamber or with bottles of water that simulate thermal mass.
Organizing space and storing food
Using a chest as a refrigerator imposes its own limitations on the organization of storage. Unlike upright refrigerators, there are no shelves and food is accessible from above. This requires special discipline and systematization.
Be sure to use baskets or plastic containers. Products should not lie directly on the bottom of the chest, as the temperature there may be lower than the average volume. Raise the supplies on a rack or trays to ensure air circulation.
It is important to consider that when you open the lid of the chest, cold air does not “flow” out, as in an upright refrigerator, but remains inside. However, warm air coming in from above can quickly cool and create condensation. Therefore humidity inside it will be high.
| Product type | Recommended zone | Shelf life | Features |
|---|---|---|---|
| Meat and fish | Lower tier (closer to the bottom) | 3-5 days | Requires the lowest temperature |
| Dairy products | Middle tier (in baskets) | 5-7 days | Keep away from drafts when opening |
| Vegetables and fruits | Top tier | 1-2 weeks | Ventilation needed, avoid freezing |
| Drinks | Along the walls | Until the date on the package | Glass may burst if overcooled |
Do not overcrowd the chest. To operate effectively in refrigerator mode, a supply of air is required. Circulation allows the temperature to equalize faster after opening the lid.
Why can’t you store bread in a freezer-refrigerator?
Bread quickly becomes stale at a temperature of about 0°C due to the process of starch retrogradation. In a regular refrigerator (at +4°C) this process is slower, but in a freezer (-18°C) it stops. In the “refrigerator” mode, the chest can keep the temperature ideal for quickly staling bread.
Humidity control and combating condensation
One of the main problems when operating the chest in refrigerator mode is excess humidity. Since the temperature of the evaporator inside the chest still remains very low (it is designed for a freezer), moisture from the air actively condenses on the walls and products.
This can lead to rapid growth of mold and damage to food packaging. To combat this phenomenon, it is recommended to regularly wipe the internal surfaces and use Desiccants. You can place open containers with silica gel or special moisture tablets in the chest.
It is also worth paying attention to the tightness of the lid seal. In refrigerator mode, temperature differences are smaller, but frequent opening can wear out the rubber faster. Check seal for cracks and, if necessary, lubricate it with silicone grease for elasticity.
- 💧 Wipe the walls with a dry cloth every 3-4 days.
- 🌬️ Leave gaps between food items for air to pass through.
- 🧼 Use baking soda to eliminate odors and absorb moisture.
⚠️ Attention: If you notice ice on the walls or food, it means the temperature has dropped below zero. Urgently adjust the thermostat settings.
Energy efficiency and compressor life
Using a chest freezer as a refrigerator can affect its energy consumption and service life. A compressor designed to be turned on infrequently to maintain -18°C will turn on more often in +4°C mode, but will operate for less time. This is not necessarily harmful, but requires control.
Modern inverter-controlled compressors easily adapt to new conditions. However, older models may experience difficulties with frequent starts. Starting current each time it is turned on, it creates a load on the motor windings.
On the other hand, the thermal insulation of chests is usually better than that of refrigerators, thanks to thick walls and horizontal opening. This means that in refrigerator mode it will be very economical, since the cold will remain for a long time even if the power is turned off.
Monitor the temperature of the compressor housing. If it overheats, the operating mode may be selected incorrectly, or the chest is installed in a too hot room without clearance for ventilation.
Frequently asked questions (FAQ)
Is it possible to completely disable the freezing function without an external thermostat?
In most household models, no. The internal mechanical thermostat does not have a positive temperature scale. An attempt to set the “minimum” often leads to either a complete stop of the compressor or operation in low freezing mode (-5...-10°C). Accurate control is only possible with an external device.
Is it safe to store glass bottles in such a refrigerator?
Yes, but with caution. Since the risk of accidentally dropping the temperature below zero (due to thermostat inertia or failure) remains, it is better not to place glass containers with liquid close to the walls and bottom. When the liquid freezes, it expands and can break the glass.
How often do you need to defrost the chest in refrigerator mode?
Despite the positive temperature in the chamber, a “fur coat” will still grow on the evaporator inside the case due to condensation of moisture from the products. It is recommended to defrost and completely wash them every 3-6 months, depending on the moisture content of the food.
Will an external thermostat consume a lot of electricity?
Modern digital thermostats consume negligible energy (less than 1 W). Their impact on the overall electricity bill will be unnoticeable compared to the work of the chest compressor itself.
Is this method suitable for commercial chests with display glass?
The principle is the same, but commercial chests are often more powerful. For them, it is especially important to use thermostats with a large margin of switching current or connect through a contactor, since the starting currents of industrial compressors are high.