Across the archive, the same conclusion keeps reappearing: effective passive climate control is not one trick but a coupled system. Water stores heat, surfaces exchange heat with the sky, and comfort depends on making that exchange feel better than conventional air systems.
| Page | Contribution |
|---|---|
| Night-sky radiative cooling | Establishes the sky as a heat sink — surfaces cool by radiating to space, not by contact with air. |
| Building thermal storage | Makes water storage part of the envelope — "the addition of energy storage to buildings is of utmost importance whether we plan to use power plants or nature." |
| Cool Cell architectural climate-control | Shows the building-scale water/roof loop — five operating modes, no refrigerants, no compressor. |
| Radiant cooling design brief | Argues for radiant comfort and adoption. |
| Sunmen | Frames the work as a measurement-driven practice: a Sunman's education begins with picking up an infrared scanner. |
Baer's "Night and Day" essay reverses the common intuition: "Does cold air cool the ground at night? No, it is the other way around; the air is cooled by contact with the ground, which first cools itself by shining heat into space." The heated vs unheated plates experiments proved that on clear New Mexico nights, a horizontal plate with 9.5 W/ft² of electric heat cannot reach ambient air temperature — the sky is pulling heat away faster than the heater can supply it. Night is never more than 12 hours away, so coolth can be replenished on a reliable 24-hour cycle.
Three gallons of water per square foot of ceiling, rising and falling 10°F, absorbs a day's internal heat from people, lights, and appliances (~250 BTU/ft²). Water weighs half as much as masonry and stores twice the heat per volume. And the same medium that stores coolth in summer stores warmth in winter: "Whatever suits natural heating and cooling will also suit the electric grid."
The archive learned that physics alone does not sell buildings. The Cool Cell system specifies that water reservoirs in the ceiling radiate heat downward in winter and absorb rising warm air in summer — radiant comfort, not forced-air drafts. The di-thermal roof brochure quotes Ed Allen's How Buildings Work on why ceiling radiant panels feel better than floor systems. The systems must "feel better than forced-air substitutes." Sunmen adds the cultural dimension: the work is inseparable from "the ugly and the beautiful," and success requires clarity, tools, and direct measurement — not subsidies or point systems.
sky exchange + water storage + radiant comfort + good measurement = believable passive HVAC
The archive is not arguing for a single device. It is arguing for a design stack: let roofs and walls radiate, let water carry the thermal load, and let the occupied space feel good enough that people will choose the system. The technical claims and the cultural claims reinforce each other.
That is why the pages about roofs, shutters, slabs, pool heaters, and design briefs all converge. They are variations on the same architecture: make the envelope do useful work, then make that work legible and comfortable.
If the archive has a center of gravity, it is this: passive climate systems succeed when they are simultaneously physical, measurable, and livable. The physics alone is not enough; the comfort story alone is not enough; the measurement story alone is not enough. The archive only becomes coherent when all three line up.
The politics cut against it. As Baer notes, "those favoring power plants are unlikely to favor heat storage that is compatible with natural heating and cooling." And Sunmen calls out the irony of subsidies: "One can no more subsidize the sun than heat it up." The archive's answer is not political but empirical — measure it, build it, make it comfortable, and the system speaks for itself.