Carrier Transicold recently introduced three diesel-powered models to its Supra line of medium and heavy truck refrigeration units: the 650, 750 and 850.

According to the manufacturer, the units' acoustically designed housing cuts sound levels almost in half.

“The sound output of the new Supra series is about as low as previous models equipped with a noise-reduction package,” said Dave Kiefer, product manager for Truck Products.

The housing is made from a composite material that resists damage and is easy to clean, said Carrier.

In addition, a bottom panel “significantly improves sound quality.”