Off-highway gets cooler and greener

An environmentally benign A/C refrigerant rooftop unit is ready for testing in logging and mining equipment in Australia.

The refrigerant R-152a has generated interest because it has very low global warming potential-90% lower than R-134a, the refrigerant presently in use. If tests in Austrialia prove successful, the refrigerant could gain stature as a candidate to replace R-134.

Carbon dioxide, which is another candidate even lower in global warming effects, is under development as an alternative, but poses higher cost issues, and, at best, is further down the road in terms of development. R152a would be a technically less difficult replacement. It has a lower molecular weight than R-134a, so about 40% less refrigerant would be needed to provide cooling performance comparable to R-134a. In addition, R-152a may provide a modest improvement in efficiency over R134a.