Advanced Energy Efficiency, Lecture 2: Industry - Rocky Mountain ...

A peculiar pedagogic error
◊ An RMI PhD engineer’s review of all main U.S.
engineering textbooks found none that correctly
presents two basic design cases
They say to optimize pipe diameter against saved friction,
ignoring the capital cost of the pumping equipment
They say to optimize thermal insulation against saved heat
cost, ignoring the capital cost of the heating equipment
Instructions for designing a wall or a window by itself are no
substitute for a way to design a whole house combining them
America’s ~$9 trillion worth of houses reflect this design error
◊ It’s common for businesses to ignore lifecycle
costing by counting only capex, not opex
◊ But this is the opposite error—it counts only opex,
not capex (beyond that of one narrowly defined
component—the insulation or the pipe)