It's Not Rocket Science #5: Night Sky Radiant Cooling

Published March 1, 2013.

Key findings

Traces the lineage from the Hay-Yellott 1967 prototype (170 ft² of ponds, fully passive/pumpless) to Zomeworks’ Double Play, and states explicitly that Double Play systems use active pumped circulation, not pure thermosiphon — “pumps are more efficient than fans in moving it around.” Confirms Baer’s radiator-design philosophy: the plate acts as a “sensor,” reacting to ambient weather variables.

Why it matters for this archive

Directly complicates the archive’s usual “passive/no pump” framing of the Double Play system: even at building scale, Zomeworks’ actual production design already uses a pump rather than pure passive thermosiphon. This is important precedent for Miniature thermosiphon scaling limits — if building-scale Double Play needed a pump, a doghouse-scale version very likely does too.