Understanding Refrigerator Repairs – The First Thing You Need to Know
Many refrigerator repairs could have been prevented or completed by the owner or user of the equipment. These types of problems are typically caused by not understanding how the equipment works. By understanding the movement of heat most problems can be understood.
If coolers make things cold then why not look at the movement of cold? We can't do that because “cold” does not exist. It is only the absence of heat. We can not put cold into something, we can only take heat of it. So understanding the movement of heat is essential.
Heat flows from an area of more heat to an area of less heat. This is the foundation of all refrigeration. If you put hot food in a fridge, the heat will move out of it. If you put frozen food in a fridge, heat will move into it causing it to thaw.
For this example there is an excess of heat in the product to be cooled. Let's say the food is room temperature at 70 degrees Fahrenheit. The heat flows into the air in the refrigerator which is 38 degrees Fahrenheit.
The evaporator coil is the part that gets cold in the box. It is usually 10 degrees colder than the air in the box. So the heat flows from the air into the refrigerant (freon) in the coil. The purpose of the fan is to keep the air moving over the coil so the heat will come into contact with it.
The compressor increases the pressure and temperature of the refrigerant so the heat can keep moving. The temperature of the refrigerant is typically 20 degrees higher than the surrounding air. The heat flows out of the condenser coils and into the air. This is the heat you can feel coming off of refrigeration coils. It is the heat from the heat removed from inside the box plus a little extra added by the work of the compressor.
The heat could be followed through the air conditioner in the same way. It is absorbed by the evaporator in the air handler. It travels through the refrigerant and is rejected by the condenser coils in the outdoor unit. Air conditioning is a form of high temperature refrigeration.
The need for refrigerator repairs occurs when the movement of heat is interfered with. Then the box is too warm.
A bad evaporator fan motor, dirty evap coils or an overfilled box keep the heat from reaching the evaporator coils.
A leak means there is not enough refrigerant to carry the heat. A bad compressor or thermostat means the refrigerant is not moved through the circuit.
A dirty condenser or bad condenser fan motor prevents enough air from flowing to absorb the heat. Since heat flows from areas of more to less, hot surrounding air makes it harder for the heat to flow into it. That is why your air conditioner works better on mild days that on hot ones.
By figuring out where the heat is having a problem flowing, you usually have found the problem. Refrigerator repairs are much easier with this this perspective. The next step is to understand what the unit is suppose to be doing. Link to refrigerator repairs.