In hot humid climates, an air conditioner must reduce the indoor humidity level of a room to make it comfortable. Otherwise, the environment inside the room will feel uncomfortably damp even after the air gets cooled. This problem is mostly noticed in inappropriately sized air conditioners. Large air conditioners cycle off before humidifying the air even after cooling it quickly. However, in extreme humid climates, even properly sized air conditioners also cannot significantly lower the humidity levels.
According to one technology, this problem is caused by the dehumidifying heat pipe that dehumidifies the air and efficiently cools it. This heat pipe is suitable for hot, humid environments.
A dehumidifying heat pipe has similarities with two heat exchangers that are located on either side of the air conditioner’s evaporator coil. These two sections are connected by several tubes. The pre-cooling of the incoming supply air is done by absorbing the heat from it by the use of a refrigerant (usually an HCFC) inside the tubes. This results in the evaporation of the refrigerant in the tube. The further cooling is performed by the air conditioner evaporator by the extraction of up to 91% more water vapor than a conventional evaporator would do. On the changing of the refrigerant in the tubes into a vapor, it flows to the condensing section at the other end of the system. There its heat is released into the air stream and it returns to its liquid state again. Then the refrigerant flows to the evaporator end of the pipe due to gravity and the cycle begins again.
Dehumidifying heat pipes can retrofit most models of heat pumps and central air conditioners. You have options to choose a replacement cooling coil that incorporates the heat pipe, or add-on heat pipes for the unit’s ventilation system. You can also consider a complete air-conditioner unit that incorporates the heat pipe.
The heat pipes don’t use any electricity directly but, they cause the conditioned air to leave the system slightly warmer than it would have in the absence of the heat pipe. Hence, it uses more energy to cool your home. More fan power is also consumed by the system to blow past the heat pipe. However, according to the manufacturer, your thermostat can be set higher with low humidity air and it allows a net energy savings.