In the blogs at csemag.com

David Sellers, PE, senior engineer with the Portland, Ore., office of Facility Dynamics and CSE’s “A Field Guide for Engineers” blogger continues his detailed analysis of energy use in engineered building systems. “In my previous post,” said Sellers, “I mentioned that using an electric resistance coil to generate a Btu of heat can be expensive relative to bu...
By Consulting Specifying Engineer Staff October 1, 2007

David Sellers, PE, senior engineer with the Portland, Ore., office of Facility Dynamics and CSE ’s “A Field Guide for Engineers” blogger continues his detailed analysis of energy use in engineered building systems.

“In my previous post,” said Sellers, “I mentioned that using an electric resistance coil to generate a Btu of heat can be expensive relative to burning a fossil fuel on-site for the same purpose because of the difference between site and source energy.”

If one only considers energy crossing the site boundary and the conversion efficiency of the electric heating coil, electric resistance heat seems like a the right choice. “So, why wouldn’t you want to use electric resistance heat and what makes it so expensive?” asked Sellers. “The answer to that question lies in the difference between site energy and source energy.”

Sellers also has posted two parts of a series he titles, “Art, Craft, and Engineering” that discusses the “art and craft and struggle and passion” of developing HVAC control sequences.

“When I first started to design, dealing with the realities that a design day imposed upon the system I was contemplating was all consuming,” said Sellers. “When it finally occurred to me that the design day represented only a tiny fraction of the operating reality my systems would have to deal with, I saw things from a new perspective; i.e. I had a new insight.”

Read Sellers’ entire blog and comment at www.csemag.com .