Thermo King APU filter receives California verification

10 June 2008

The California Air Resources Board (ARB) verified Thermo King’s eDPF active diesel particulate filter as a Level 3 (≥ 85% PM emission reduction) diesel emission control system. The verification is conditional upon completing the remaining durability demonstration requirements.

The system has been verified for use with TriPac auxiliary power units (APU) powered by Tier 2, MY 2006-2008 Yanmar TK270M diesel engines. Thermo King’s eDPF uses an SiC wall-flow filter with an electrical heating element for regeneration.

The device is the first Level 3 system verified for APU application.

APUs are small generator sets fitted on highway trucks to provide power for the driver’s cabin (such as for air conditioning or heating) during overnight parking, to eliminate the need for idling of the main truck engine. Under California idling regulations, trucks with MY 2007 and later engines are required to either route the APS’s exhaust through the particulate filter of the main truck engine or to retrofit the APS separately with a Level 3 PM control device. This requirement became effective from January 2008. However, due to a combination of technical and commercial reasons, most engine manufacturers disallow routing the APU exhaust through the main engine filter, which makes the Level 3 retrofit the only compliance option.

Source: California ARB