By Paul Abelson, senior technical editor
It doesn’t matter if you have all the power in the world to run an air conditioner with enough Btu to cool a meat locker. If your truck lacks insulation, you might as well be trying to cool the great outdoors.
No matter what the idle-reduction device, it will work better and last longer if the cab is well insulated.
TMC Recommended Practice, RP 434, Cab and Sleeper Insulation Efficiency Guidelines, addresses standard and premium packages. Standard insulation should have a minimum “R” value of 4.2. Premium is considered any insulation greater than R 4.6. Any material must meet the flammability standards of FMVSS 302.
Regardless of what insulation package is installed on your truck, there’s still opportunity to improve upon it.
The limiting factor for how much insulation a truck should have is how much room there is to put it in. After taking delivery, many new truck owners add urethane foam or non-woven polyester or other fibers, including fiberglass, between the outer skin and inner liner.
Don’t forget to insulate the floor. The transmission that weighs from 700 to 900 pounds acts as a giant heat sink, stabilizing at the transmission’s operating temperature around 200 degrees. Without air circulation, that heat radiates to the floorboards, heating the cab. Foam with a reflective coating will help considerably. LL