In this article I would like to talk about the refrigerators and freezer units commonly found in a commercial kitchen and restaurant. The average unit will give long service with minimal maintenance; however there are a few things you should know that could possibly prevent breakdowns. You should also read Greg’s article on this subject he posted some time back.
The way it works: Any common unit used to cool (refrigerator or freezer) that operates with a refrigerant (freon) works in essentially the same way. I will give you a rough outline so you will get the basic idea.
Every commercial refrigerator or freezer is made up of 3 main parts you can identify:
1. The compressor: the compressor is really nothing but an electric motor that is sealed (welded) in a metal case. The case will be located on the outside of the unit (not in the compartment to be cooled). Compressors are made by several companies and in various styles but most compressors are made by Copeland. You cannot mistake the compressor for anything else because nothing else on your cooling unit will look like the compressor. Think of the compressor as the HEART of your cooling unit. There is no maintenance that can be done on a welded compressor. It is full of oil but typically the oil is designed to last the life of the compressor.
When a welded compressor goes out all you can do is replace it. A compressor is expensive but it is often cheaper to replace the compressor than to replace the entire unit. I have also replaced compressors because the particular equipment was built into “the line” and it has to repaired rather than replaced.
2. The condenser coil: The condenser coil is square, usually black in color, and will have a fan placed behind it that forces air through it. Most of these coils are around 12 inches by 12 inches. The condenser coil will be located very near the compressor (usually directly in front of it). The fan that forces air through the coil is almost always located between the coil and the compressor. This fan not only removes heat from this coil but has the added benefit of cooling the compressor. You must keep the area where this coil and fan are located FREE FROM ANYTHING that blocks air flow (i.e. don’t stack boxes on top of or in front of the area where the compressor and coil are located). The condenser coil will require cleaning on a regular basis (every 3 months). The coil will pick up whatever is floating in the air in your kitchen and deposit it on the coil.
If you allow the coil to clog up, it will cause your cooling unit not to perform at it’s optimum. In fact if this coil is left completely clogged for any extended period of time it will shorten the life of your compressor or completely burn it up. Think of this coil as one of the LUNGS of your cooling unit. Without air, the HEART (the compressor) will stop.
3. The evaporator coil: the evaporator coil is also called the “cold coil”. This coil is located inside the compartment to be refrigerated. In most cases you will not be able to see this coil without removing a cover. This coil’s purpose is to distribute cold air into the unit. Like the condenser coil, there is a fan near the evaporator coil used to force air through it. The evaporator coil can be many different sizes and is usually a lot thicker than the condenser coil. It is often a silver color (aluminum) and can have several fans blowing air through it. Think of this coil as the other LUNG of your refrigeration unit.
The evaporator coil gets extremely cold when the unit is running. Air on the inside of the refrigeration unit is re-circulated through this coil over and over again and getting colder with each pass. This air is what makes your unit cold. It takes the heat from any object you place in the cooling unit and transfers it to the evaporator coil. The heat is then absorbed by the refrigerant (freon) passing through this coil and delivered to the rest of the system (compressor and condenser coil) to remove it from the unit.
These three main components work in unison to cool your refrigerator or freezer. Your freezer will also be equipped with a defrost heater that melts the frost off the evaporator coil several times a day to keep it from freezing up.
What you as a owner/manager can do:
You can extend the life and efficiency of your refrigerators and freezers by keeping the condenser (outside) coil clean. You can also insure the door gaskets are in good shape and are sealing all the way around. Also train your employees not to leave the door open any longer than necessary.
The refrigerators and freezers are some of the most maintenance free equipment in your kitchen. If you buy a quality unit and see that the minor maintenance described above is done then these units should give you many years of trouble free service.