Refrigeration appliances can be affected by the environment they are placed in if the temperature moves outside its climate rating specified by the manufacturer (Climate Classes for fridges, freezers and fridge-freezers).
If placed in an environment where the room temperature gets up to around 30 degrees most units sold in the UK may start to struggle to work if they can’t give off the heat from the condenser (normally at the back of the unit which gets hot). The ambient air temperature around the condenser needs to be 10 degrees lower than the condenser so that the energy can be given off as radiant heat. If the heat from the condenser can’t radiate away into cooler air then the heat won’t be taken out of the food so it won’t get cold.
In a normal home these temperature ranges shouldn’t cause any problems as the fridges and freezers we use are designed to operate in the UK home.
What happens if you put a fridge or freezer in a garage, shed or cellar?
If the maximum temperature is exceeded the appliance will struggle to keep the temperature inside down as described above and could be running constantly or at least for longer periods than necessary. This could cause overheating, breakdowns and higher energy bills.
If the temperature drops below the minimum stated on the climate rating (which is more likely) a fridge-freezer controlled by only one stat may even switch off and defrost. Typically in the UK the temperature range is 10 degrees C to 30 degree C
Many thousands of people do have a refrigeration appliance installed in a garage and most don’t have any problems that they are aware of, particularly with freezers. Fridge-freezers are more susceptible to issues. As it happens I have my own freezer, and a second fridge in my garage, which is a separate building and gets pretty cold in the winter. Mine don’t suffer from the problems associated with a combined fridge-freezer fitted with one thermostat in the fridge as described here (not all fridge freezers have only one stat btw) Freezer defrosted: Can you put a fridge freezer in a garage?.
Another issue with refrigeration in a cold room such as a garage or cellar is condensation and black mould. The cool damp air is attracted to the warm parts of the fridge’s outside wall where condensation can form. This is not normally anything to worry about but you may get mould growing on the rubber door seal and it can cause a deterioration of the cabinet due to rust.
If the condensation on the door or sides is constantly there, or is present in small patches all of the time, even when it isn’t cold then it could point to a breakdown in the insulation and is greater problem. If the insulation has gone in a certain part of the fridge or freezer cabinet you will be constantly losing cold air from inside the appliance and it will run for longer and use more energy. A breakdown in insulation is usually terminal.