I read the article in your September issue, Environmental regulations, A look at what CARB is doing and planning, which was based on a presentation made to the Truckload Carriers Association Refrigerated Division Annual Meeting, and I would like to correct some misinformation regarding the 50% control devices for TRUs.

As the only manufacturer of a CARB approved 50% control device for TRUs, I assume the presenter, Mike Tunnell of ATA, was referring to our Proventia TRU filters developed for all of the Thermo King transport refrigeration units.

Proventia is not aware of any limitations of our device, as mentioned by Mr. Tunnell in the article. The Proventia TRU filter is verified for all models of Thermo King trailer TRUs, from model years 1985 through 2002.

Proventia TRU filters for Thermo King bobtail TRUs could also be available, depending on customer demand.

I would like to note that installing the Proventia TRU filter doesn't cost as much as repowering with another engine. The installed cost is a 30% to 50% savings, compared with a repower.

Further, a filter can be installed in 2 to 3 hours by a fleet's own mechanics, where as a repower may tie up a TRU for days.

To help clarify the technical side of TRU filters, Proventia has a video on its website - www.proventiafilters.com - showing what is involved in an installation, along with downloadable owner manuals.
Tom Sem
North American Representative
Proventia Emission Control