Double Play Structures — Zomeworks (R&D page)

Zomeworks Corporation’s own R&D page describing the productized “Double Play” building system. Fetched and verified 2026-07-13.

How it works

• Summer: “Warm air rises to the mass of water in the ceiling and cool air returns.” At night the rooftop radiator/absorber coils dump the stored heat to the night sky.
• Winter: “Heat radiates from above and can be blocked with aluminum louvers: heat radiates to the space below only when the louvers are open.”

Components

• One or more absorber panels on the south side
• Water storage located in the ceiling (thermal mass)
• Radiator/absorber cooling coils on the roof (night-sky rejection / solar gain)
• Aluminum louvers to control radiant heat flow
• Optional fan to circulate warm air when radiant heat alone is insufficient

The concept is credited on the page to Norman Saunders, as explained in Bill Shurcliff’s book Super Solar Houses.

Demonstration buildings

• Two test outbuildings were constructed at Zomeworks headquarters. “One building is now for sale while the other is used for meetings and tours.”
• A 20’ × 8’ cargo container was retrofitted as a Double Play structure using water bladders on the roof instead of ceiling storage — a “much less costly application” — “to be tested in Albuquerque.”

Ideal climate

“Double Play systems work best in dramatic climates such as the West and Southwest of the United States, where nights are cool, days are hot and winters are sunny.”

Status & remaining challenge

The original building design needs “more development to bring down costs.” The cargo-container iteration is the low-cost path being pursued.

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Note: This is the vendor/primary description of the productized system. For the technical lineage and independent academic account, see Steve Baer and the Double-Play Thermosiphon (Kayatekin, ICON 2025) and the 2004 Bruce Davis Studio progress report.