Tools in My Closet – GreenBuildingAdvisor

By Martin Holladay | May 2, 2025

While cleaning out a closet recently, I came across two instrument cases that I inherited from my grandfather after he died in 2000 at the age of 98. The first is an old-fashioned leather-strapped wooden tool case that holds three thermometers, each with a dial face and a long icepick-like temperature probe. The second is an unusual, decades-old battery-powered psychrometer—an instrument for measuring atmospheric moisture.

I’ll get back to these instruments eventually—after a detour in which I mention some highlights of my grandfather’s career. William L. Holladay was a refrigeration and air-conditioning engineer—a field that didn’t even exist when he was born in 1901. In many ways, his life was punctuated by events that shaped the development of the HVAC industry in the U.S.

The Forrest Gump of HVAC 

My grandfather wasn’t particularly well-known, but he managed, like Forrest Gump, to intersect with several historically important events. My grandfather:

• Was for decades a leading member of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE);
• Helped develop the first household refrigerators sold in the U.S.;
• Helped develop one of the earliest air-source heat pumps in the U.S.;
• Designed and built low-temperature test chambers and high-humidity test chambers used by building science researchers and HVAC equipment researchers;
• Developed new calculation methods for HVAC engineers to determine an appropriate outdoor design temperature in the absence of adequate meteorological data; and
• Investigated building failures caused by poorly designed HVAC systems.

In each of these fields, he was a pioneer.

Early years

As a child, William Holladay was a tinkerer; he built his own wireless set at age 10—in other words, at the dawn of the radio age. A few months after graduating from Caltech in 1924 with a degree in electrical engineering, he was hired…