What is a Heat Exchanger?
Air conditioners work by pulling the heat from surrounding air, and expelling the warm air out of the room. This creates cool air that is then circulated around the room, cooling the space in the process. The heat exchanger is responsible for this function, and the efficiency of this AC component determines the cooling capacity of the unit.
The heat exchanger is the component in air conditioning systems used in heating fluid, such as coolant or refrigerant. The heat exchanger is used in both heating and cooling systems, as the process creates hot and cold air that can be fanned into the room.
There are multiple types of heat exchangers. There are shell and tube heat exchangers, and finned tube heat exchanger, as well as efficient designs like plate heat exchangers, frame heat exchangers, and other heat exchangers. Heat exchangers are also commonly known as the condenser and the evaporator.
How Do Heat Exchangers Work
Heat exchangers work by transferring heat from one medium to another. The medium must have a considerable temperature difference for the process to work, and heat exchangers may work with hot water and cold water, air, or other mediums. An air conditioner heat exchanger uses the surrounding air and the refrigerant or coolant.
In this case, air conditioner heat exchangers transfer heat to the refrigerant liquid, turning the coolant into a gas. This process is done via the evaporator coils, and the cooled air created in the process circulates around the room.
The condenser coils, on the other hand, transfer heat from the refrigerant gas to the air. The heating and cooling medium travel in opposite directions, and do not have direct contact during the process. Heated fluids cycle back into the condenser, and the medium that flows through these tubes exchange heat to subcool the refrigerant.
In cooling systems, the exhaust gases are expelled outside the air conditioner through the fan, and the subcooled refrigerant cycles back through the evaporator to repeat the process. In space heaters, the warm air is circulated back into the room, and the cold air is flown outside.
Different types of heat exchangers have different efficiencies, with the plate heat exchanger and the concentric tubular heat exchanger. These are designed to facilitate the heat exchange between the refrigerant (cold fluid) and a hot fluid or medium, considering the temperature differential at increased efficiency.
Diagnosing a Faulty Heat Exchanger
As this aircon component is responsible for facilitating heat transfer from one medium to another, faulty heat exchangers can cause the HVAC system to malfunction. Heat exchangers must maintain sufficient fluid velocity in order to function properly, and without proper maintenance, the component can break down. Here are the common signs:
#1 The Air Conditioner is Not Cooling
If the air conditioner is not cooling the room at all, it may be because the refrigerant is not processed properly. This is sometimes due to the heat exchanger unable to remove heat from one medium, and transfer it to the other. The coolant pressure drops, which causes the AC unit to malfunction as it cannot cool the air inside.
#2 HVAC System is Not Heating
HVAC systems have space heating capabilities, and can be switched to provide warm air flow instead of cold air. Similar to air conditioners and cooling systems, a faulty heat exchanger will not be able to transfer thermal energy from one medium to another, causing the HVAC unit to fail to blow warm air into the room.
#3 Inadequate Cooling/Heating
Inadequate cooling or heating is when the unit is functioning, but cannot reach the desired temperature set on the thermostat. This is sometimes due to a failing heat exchanger that is struggling to work its processing systems to sufficiently cool or warm the air.
Air Conditioner Heat Exchanger Maintenance
Heat exchangers are essential to air conditioners as they cool the air in the room. Maintaining these components is key to keeping the AC unit running smoothly. Here are some tips to keep the heat exchanger system in good condition:
- Have the AC unit professionally cleaned once every 4-6 months.
- Clean the condenser coil and evaporator coil.
- Clean the filter every two weeks.
- Avoid overworking the air conditioner.
For all your air conditioner needs, Luce Aircon is here to provide you with the best cleaning, repair, and maintenance services. Our experienced technicians will work with you to create a maintenance plan for your air conditioner, so you can enjoy its cooling comfort for years to come!
Contact us today to schedule your next aircon cleaning, maintenance, or inspection appointment.