One common customer complaint about their central HVAC systems is that the a/c system is running but not providing any cool air to the controlled space. One of the most common reasons for this situation is that the a/c condenser or evaporator coil has frozen over. This term or phrase literally means that ice has formed on the heat exchanger, preventing the transfer of heat since the ice is acting as an insulator.
To keep their units operating at peak efficiency, homeowners are encouraged to schedule regular system maintenance. However, there are a number of problems with this approach. As a result, companies are developing hardware/software products to provide a means for monitoring and maintaining optimum performance of residential HVAC units.