concepts · updated 2026-07-19
USAF Passive Solar Handbook
confidence: high volatility: cold verified: 2026-07-19fresh
A 5-volume US Air Force passive solar design handbook (c.1985, Architectural Energy Corp for USAF/LEEDE), representing the mid-1980s institutional canon of passive solar engineering. Its passive-cooling section covers only air-based strategies (night mechanical ventilation, natural ventilation) -- no mention of Hay, Baer, Zomeworks, Skytherm, or roof ponds anywhere in the document.
Publisher: United States Air Force. Contractor: Architectural Energy Corporation, Boulder, CO (Michael J. Holtz, AIA, President). Date: c. 1985–87. A 5-volume series (Volume I: Introduction to Passive Solar Concepts; Volume II: Comprehensive Planning Guide; Volume III: Programming Guide; two further volumes proposed but not confirmed complete). Written for USAF facility planners, programmers, designers, and construction supervisors worldwide, in response to the 1970s oil embargo and Executive Order 12003 (1977).
What it covers
Eleven passive solar strategies across three categories: Solar Thermal (direct gain, indirect gain, sunspaces), Passive Cooling, and Daylighting. The passive-cooling section is entirely air-based: Night Mechanical Ventilation (using existing HVAC fans/ducts to flush a building with cool night air, resetting thermal mass) and Natural Ventilation (opening windows when outdoor temperature is below indoor, most effective in spring/autumn). The handbook states these two strategies were “most successful in the commercial-type buildings analyzed.”
What it omits
No mention of Harold Hay, Steve Baer, Zomeworks, Skytherm, or roof ponds anywhere in the document — despite Hay’s Skytherm having existed for 12–18 years by publication, with results reported to Congress in 1974 and recognized by the Bicentennial Commission in 1976. The suggested-reading list cites Mazria’s The Passive Solar Energy Book, ASHRAE and DOE/SERI technical manuals, and other institutional sources — none touching water-based night-sky radiative cooling.
Why it matters for this archive
By 1985 the federal government had a 5-volume institutional handbook that defined “passive cooling” as air movement, not radiation — reaching engineers across hundreds of USAF bases worldwide with zero exposure to the water-based approach Hay and Baer had already spent over a decade proving. This is concrete evidence, alongside A Golden Thread, for why passive thermal hasn’t scaled: the dominant institutional definition of “passive cooling” excluded night-sky radiation entirely, not through active rejection but apparent non-contact between the counterculture and institutional traditions.