The latest optional engine emissions system (EES) for Carrier Transicold X4 and Vector Series trailer refrigeration units has received conditional CARB level 3+ verification from the California Air Resources Board. The EES, according to the manufacturer, is the first OEM-developed CARB level 3+ verified diesel emissions control (VDEC) device for trailer refrigeration units that can be included with the initial purchase of a TRU or added later for operations that do not initially require it.

Although trailer refrigeration units can be specified with the EES at the time of the initial purchase, Carrier Transicold designed the system for ease of installation as a retrofit, since many users will not require it immediately.

A Level 3+ VDEC device reduces particulate emissions in accordance with CARB’s ultra-low emissions requirement for transport refrigeration units, known as ULETRU, while also reducing nitrogen oxides. ESS, Carrier Transicold noted, is capable of reducing diesel particulate mass from trailer refrigeration unit exhaust by more than 98%.

The EES is conditionally verified for use with Carrier Transicold’s new Tier 4-compliant designs, which include X4 Series single-temperature models 7500 and 7300, and hybrid Vector 8500 single-temperature and Vector 8600MT multi-temperature units. In the current phase of the verification process, these Carrier Transicold units may be factory-equipped with the EES, and the EES can be installed on previously purchased units with up to 3,000 hours of engine operation.

“Carrier Transicold’s latest trailer refrigeration unit engines are already certified for ‘evergreen’ compliance with the 2013 EPA Tier 4 standard for engines less than 25 horsepower, allowing for indefinite use throughout North America, except in California,” said David Kiefer, director of marketing and product management, Carrier Transicold. “In California, CARB uniquely requires that a VDEC strategy be applied to units in this horsepower class for use in the state beyond the initial seven years. CARB conditional verification validates the operation and effectiveness of the EES in our 2013 Tier 4 refrigeration units. This is a major milestone and the first and biggest step toward offering a broader array of CARB-compliant options to our customers.”