The HVAC industry has seen a significant increase in thermostatic expansion valve (TXV) usage in the past decade. In 2006, the U.S. Department of Energy (DOE) set new standards for newly manufactured residential air conditioning systems. Whereas the previous standard had mandated a SEER of 10, the latest standard requires new systems achieve a SEER of 13 or higher. This new requirement has affected systems in various ways. For example, prior to 2006, the majority of residential air conditioning systems used pistons or simple orifice-type metering devices. Currently, the majority of residential air conditioning systems are equipped with a TXV as the metering device.
Even though TXVs are the most popular metering devices for residential air conditioning systems, there is still a lack of knowledge about TXV functionality in the market.