The 2013 ASHRAE Handbook of Fundamentals containssix chapters under the heading “Load and Energy Calculations.”The chapters include detailed information on aspectsdirectly affecting building loads, load calculations and energymodeling. Chapter 19, titled, “Energy Estimating and ModelingMethods,” is authored by Technical Committee (TC) 4.7,Energy Calculations. The chapter introduction states, “Energyrequirements of HVAC systems directly affect a buildingsoperating cost and indirectly affect the environment.” Due tothese affects, energy analysis tools and programs have beendeveloped by a number of public- and private-sector entities.This article examines the historical development of a privatesector program: Trane Air Conditioning Economics(TRACE™).

In 1971, Dennis Bridges, manager of marketing at Trane1,and Neil Patterson, manager of applications engineering,conceptualized TRACE. To help with the implementation, theteam pulled in Dick Grant, an engineer familiar with bothcomputer programming and HVAC design. The first releasewas based on the “Post Office Program.” The “Post OfficeProgram” was created in 1971 when the U.S. Postal Servicesdeveloped a computer program to analyze energy use in postoffices.2 In fact, according to Larry Scheier, lead softwaredeveloper, there are still algorithms used in today’s version ofTRACE that use “PO” in the variable naming convention.