The conversion to 13 SEER is well behind us. Most residential air conditioning furnace coils and air handlers today use thermostatic expansion valves, or TEVs. Sometimes these are referred to as TXVs, but I looked in the dictionary and confirmed that expansion is spelled with an “e” and therefore TEV is the proper acronym. Prior to 13 SEER, most systems used fixed restriction expansion devices. So exactly how does the TEV help the unit achieve higher efficiency? In this article we will answer this question and provide some basic knowledge of TEV operation on residential unitary a/c applications.
TEVs were selected by most residential a/c equipment manufacturers because they: