ATLANTA, GA — Yeah, yeah, we’ve heard it a thousand times before: It’s not the heat, it’s the humidity.

With regards to mechanical dehumidification, heat pipes, and desiccant systems, what are the actual cost benefits of reduced air conditioning if you lower the humidity? Still more intriguing, what is the impact of dehumidification on comfort and health? Attendees of an ASHRAE forum addressing these topics were not aware of any current studies, other than a chart that shows the humidity levels at which bacteria seem to thrive. But in many parts of the world, the humid climate needs to play a more important role in a/c system design, and needs more accurate assessment against temperature. In England, for example, “Comfort is a humidity problem,” said a consulting engineer. He often tells reluctant building owners that “100 degrees is OK in the desert, but not in the rain forest.”