Danfoss is proud to announce that 15 million TR6 thermostatic expansion valves are now currently in operation throughout the United States.

The journey to 15 million TR6 valves began in 2003, when the minimum seasonal energy efficiency ratio rating for residential air-conditioning systems in the U.S. was SEER 10. That meant that most systems used a fixed-orifice metering device and only high-efficiency systems used active metering devices like TXVs.

After substantial research and customer input, Danfoss began to engineer a TXV that would meet the needs of the high-efficiency market: the TR6.

The TR6 was designed specifically for the U.S. residential air-conditioning market and with plans for it to be manufactured according to Danfoss’ strict quality standards: a laser-welded powerhead creates a longer lasting lifetime of the power element than plasma welding while also subjecting it to less stress; the internal check valve’s patented design eliminates pressure drop; and the accurate, non-adjustable factory superheat settings ensure the product works properly out of the box.

Then in 2004, the US Department of Energy announced new minimum SEER standards for air conditioning and heat pump systems manufactured after Jan. 23, 2006. Instead of a rating of SEER 10, as had been the standard since 1992, the new minimum rating would be SEER 13, increasing the energy efficiency of a system by 30 percent. Due to its superior design, the TR6 was easily able to qualify for the new requirements.

Suddenly, fixed-orifice throttling devices would not be sufficient and the demand for reliable TXVs skyrocketed. To handle the anticipated increase in market demand, a new Danfoss automated production line was installed at the main plant in Nordborg, Denmark and few years later, to get closer to the target market and customer base in the U.S., the TR6 line was dismantled, boxed up, and shipped to Monterrey, Mexico where it was reassembled. The automated production line resumed operation in early 2009 without a single order being delayed.

Over its life, the TR6 has evolved to meet market needs. In 2015, minimum SEER requirements became region-based, with stricter requirements in the southern and western regions of the country; however, the TR6 exceeds requirements across the board. Danfoss also expanded its offering to better meet the needs of contractors using TR6 valves by developing TR6 Universal Replacement kits. The kits are available for either R-22 or R-410A and include multiple valves and orifices, offering contractors and technicians an all-in-one solution for air conditioning TXV replacement.