A fridge never makes cold — it carries heat out of the box. Use the buttons to look inside it and follow the refrigerant around its loop, from the compressor to the evaporator and back.
A refrigerator is a cabinet that keeps food cold by moving heat out of it. It never makes cold; it takes the heat inside the box and carries it outside into the kitchen. The carrier is a fluid called refrigerant, and it runs around a sealed loop again and again.
The loop has four stops. A compressor squeezes the refrigerant so it gets hot; condenser coils on the back let that heat escape; a thin capillary tube drops the pressure so the refrigerant turns cold; and evaporator coils inside the cabinet soak up heat from the food. Then the refrigerant returns to the compressor and starts over.
From the outside a fridge is just a white box humming in the corner. Everything that matters — the pump, the coils and the pressure changes — is hidden behind the cabinet, so showing the shell only faintly makes it clear where the heat actually goes.
One idea holds the whole machine together: heat always flows from something warm to something colder, and the refrigerant is a carrier that is made hot on one side and cold on the other. Everything else exists to keep that loop running quietly, day and night.
A fridge works on one simple rule: heat always flows from something warm to something cooler. To cool the food, the fridge has to take its heat and hand it to something even colder — the refrigerant. The refrigerant then carries that heat outside. Nothing in the box is made cold; heat is simply removed.
The compressor is the pump at the bottom of the fridge. It squeezes the refrigerant gas, raising its pressure. Squeezing a gas also heats it, so the refrigerant leaves the compressor as a hot, high-pressure gas — hotter than the kitchen, which is exactly what it needs to be.
The hot gas flows into the condenser coils on the back of the fridge. Because the refrigerant is hotter than the room, its heat leaks out into the air and the coils feel warm to the touch. As it loses heat, the refrigerant cools and turns back into a liquid.
The liquid refrigerant now squeezes through a very thin capillary tube. The narrow bore chokes the flow and drops the pressure sharply. That sudden drop is what makes the refrigerant cold — the same effect that makes a spray can feel cold as it empties.
The cold refrigerant enters the evaporator coils hidden in the back wall of the cabinet. Now it is colder than the food, so heat flows from the food into the refrigerant. The refrigerant absorbs that heat and boils back into a gas, and the gas returns to the compressor to start the loop over again.
No. It moves heat rather than creating cold. The inside only gets colder because its heat is carried out into the kitchen.
That warmth is the point. The condenser coils on the back give up the heat taken from inside the cabinet, so the back feels warm while the food stays cold.
The compressor is the pump. It squeezes the refrigerant gas, which both pushes it around the loop and makes it hot so it can shed heat outside.
That is the capillary tube. Its narrow bore drops the refrigerant's pressure, which makes it suddenly cold right before it enters the evaporator.
No. One refrigerant loop cools both. The freezer is simply closer to the coldest part of the evaporator, so it gets colder.
Older CFC and HCFC refrigerants damaged the ozone layer and were powerful greenhouse gases, so they have been phased out. Most modern fridges now use HFCs, or newer HFO and hydrocarbon refrigerants that are far safer for the ozone layer though they can still add to global warming.
They work on the same principle, moving heat instead of creating it. A fridge takes heat from inside the box and dumps it into the room, while a heat pump takes heat from the outside air and delivers it indoors to warm the house.
The condenser has to get rid of the heat it gathered from inside the box. Placing the coils on the back or bottom lets them release that heat into the room and lets air flow over them naturally by convection.