The Danfoss TR6—15 million and counting

 - Wednesday, July 05, 2017 By Danfoss
In 2003, the minimum seasonal energy efficiency ratio (SEER) rating for residential A/C systems in the US was SEER 10. That meant that most systems used a fixed-orifice metering device and only high-efficiency systems used active metering devices like thermostatic expansion valves (TXVs). After substantial research and multiple dialogues with customers, Danfoss decided to develop a TXV for the high-efficiency market: the TR6.

The TR6 was designed specifically for the US residential 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 January 23, 2006. Instead of a rating of SEER 10, as it had been since 1992, the new minimum rating would be SEER 13, increasing the energy efficiency of a system by thirty 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 US, 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.

While the TR6 enjoyed a successful product launch, it has evolved to meet market needs. In 2015, minimum SEER requirements became region-based, with stricter requirements in the southern and western regions; the TR6 exceeds requirements across the board. To better meet the needs of contractors, the TR6 Universal Replacement kits were created. 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 A/C TXV replacement.

The TR6 has seen great success. Starting life as a way to enter the high-efficiency residential A/C market, it is now a standard piece of equipment. We estimate that between thirty and forty percent of new A/C systems manufactured in the US use a TR6 valve. Now, just over a decade later, fifteen million TR6 are in operation around the country. It has been quite a journey, but it is just another example of how we are engineering tomorrow.