Trane unveils cold-climate heat pump operating down to -29 C

Ireland-based heating technology manufacturer Trane has introduced the 20 TruComfort Variable Speed Cold Climate Heat Pump with WeatherGuard, a residential air-source heat pump designed for regions with high heating loads and severe winter temperatures.

Unlike conventional heat pumps sized primarily according to cooling demand, Trane said it designed the new product with higher nominal heating capacity relative to cooling capacity, with the aim of better matching residential loads in colder climates.

The manufacturer said the new system uses R-454B refrigerant and has an outdoor operating temperature range extending from -29 C to 46 C.

The new product is available in nominal sizes of 3 tons, 4 tons and 5 tons.

The smallest, 3-ton unit, dubbed 5TCV0X36A1000A, has a nominal cooling capacity of 26,200 Btu/h and a nominal heating capacity of 33,200 Btu/h. The 4-ton 5TCV0X48A1000A provides 36,000 Btu/h of cooling and 45,000 Btu/h of heating.

Trane is also offering two 5-ton variants. The 5TCV0X60A1000A has rated cooling and heating capacities of 48,500 Btu/h and 55,000 Btu/h, respectively, while the 5TCV0X61A1000A provides 48,000 Btu/h of cooling and 55,500 Btu/h of heating.

According to laboratory data released by the company, the 3-ton unit can supply 107% of its rated heating capacity at -15 C and 85% at -29 C. The 4-ton model provides 100% of rated capacity at -15 C and 67% at -29 C.

Performance varies between the two 5-ton versions. The X60 unit delivers 87% of rated heating capacity at -15 C and 53% at -29 C, while the X61 model provides 100% and 70%, respectively, at the same temperatures.

Trane has not yet disclosed the system’s coefficient of performance (COP), heating seasonal performance factor 2 (HSPF2), or seasonal energy efficiency ratio 2 (SEER2) ratings.

Trane said development of the product grew out of its participation in the US Department of Energy’s Residential Cold Climate Heat Pump Challenge. An early prototype was independently tested at Oak Ridge National Laboratory in 2022 and subsequently underwent field testing.

The company said nine units were field tested in Minnesota, Montana, New York, Pennsylvania, Wisconsin and Texas, accumulating more than 36,900 operating hours, including more than 18,300 hours in heating mode. Minimum temperatures at the test locations ranged from around -29 C to -15 C.

During a January 2026 cold spell, Trane said one 5-ton test unit in La Crosse, Wisconsin, maintained the home’s setpoint without supplemental heat at temperatures as low as -29 C. Another test unit maintained its setpoint without backup heat down to approximately -23 C, after which supplemental heating was used while the heat pump remained in operation.

The company said the heat pump can be installed as part of an all-electric system with an air handler or incorporated into a dual-fuel configuration with a furnace. It is targeting applications in northern US states and other regions where annual heating demand substantially exceeds cooling demand.