Heaters and air conditioners can both have fans, but it depends on the specific type and design of the appliance.
Heaters and Fans: Many heaters utilize fans to distribute warm air more efficiently throughout the room. These types of heaters are often called "forced-air heaters" or "fan heaters." The fan helps to push the heated air out into the room, providing more even and rapid heating compared to non-fan heaters. However, there are also heater types that do not incorporate fans, such as radiant heaters that directly emit heat without air circulation.
Air Conditioners and Fans: All air conditioners have fans as an integral part of their cooling process. Air conditioners work by removing heat from the indoor air and transferring it outside. The fan is responsible for drawing indoor air through the unit, passing it over the cooling coils, and then expelling the cooled air back into the room. The same fan also helps expel the heat from the air conditioner's outdoor unit to the external environment.
In summary, while heaters can have fans for more efficient heat distribution, air conditioners always include fans as they are essential for the cooling process. The presence of a fan depends on the specific type and design of the heating or cooling appliance.