Trane upgraded and expanded its Expanse unit heater product line. The redesigned gas unit heaters now feature a tubular heat exchanger, standard on most models.

Trane says single piece construction is the key advantage tubular heat exchangers have over conventional clamshell models. The tubular design provides uniform, maximized heat transfer for increased efficiency and has a low-pressure drop, which enables heated air to be evenly distributed.

The tubular heat exchanger improvement provides operating efficiencies up to 82 percent for duct furnaces and up to 83 percent for unit heaters, says Trane.