"Houses so efficient, they can be heated with nothing more than a hair dryer!”— a statement you will find over and over again in searching the Internet for “Passive House.” So outlandish, it seems more marketing hype that reality. But Allen Gilliland, owner of Silicon Valley’s One Sky Homes and Passive House designer and contractor, puts this claim to a test in a YouTube video for a 3,200-square-foot Passive House he designed and built. In the video, Gilliland suspends a 1,600 watt hair dryer in the home’s return air plenum, turns off the home’s heating system, turns on the hair dryer (at 6:30 PM and 51 degrees Fahrenheit outside and dropping) and comes back the following morning to check the results. When he returns, the outdoor temperature is measured at 36 degrees F. Once inside, he makes a beeline to the home’s thermostat, which corroborates an outdoor temperature of 36 degrees and shows an indoor temperature of a balmy 70. Amazing.
Passive House is an ultra-energy-efficient building standard developed in Germany (using U.S. and Canadian groundwork) in the 1990s by Wolfgang Feist, and introduced in the U.S. in the early 2000s. It is a standard that has few, and very simple, requirements: super-insulate the building envelope, make it nearly airtight, eliminate thermal bridges, and use super-efficient windows. The standard’s promise in following the strict rules is a building that will use 90 percent less energy for heating and cooling than a conventional building.