Editing Autonomous building (section)

===Cooling===
Annualized geo solar buildings often have buried, sloped water-tight skirts of insulation that extend {{convert|6|m|ft}} from the foundations, to prevent heat leakage between the earth used as thermal mass, and the surface.

Less dramatic improvements are possible. Windows can be shaded in summer. Eaves can be overhung to provide the necessary shade. These also shade the walls of the house, reducing cooling costs.

Another trick is to cool the building's thermal mass at night, perhaps with a [[whole-house fan]] and then cool the building from the thermal mass during the day. It helps to be able to route cold air from a sky-facing radiator (perhaps an air heating solar collector with an alternate purpose) or evaporative cooler directly through the thermal mass. On clear nights, even in tropical areas, sky-facing radiators can cool below freezing.

If a circular building is aerodynamically smooth, and cooler than the ground, it can be passively cooled by the "dome effect." Many installations have reported that a reflective or light-colored dome induces a local vertical heat-driven vortex that sucks cooler overhead air downward into a dome if the dome is vented properly (a single overhead vent, and peripheral vents). Some people have reported a temperature differential as high as {{nowrap|8 °C}} ({{nowrap|15 °F}}) between the inside of the dome and the outside. [[Buckminster Fuller]] discovered this effect with a simple house design adapted from a [[grain silo]], and adapted his [[Dymaxion house]] and [[geodesic dome]]s to use it.

Refrigerators and air conditioners operating from the waste heat of a diesel engine exhaust, heater flue or solar collector are entering use. These use the same principles as a gas refrigerator. Normally, the heat from a flue powers an "[[absorptive refrigeration|absorptive chiller]]". The cold water or brine from the chiller is used to cool air or a refrigerated space.

Cogeneration is popular in new commercial buildings. In current cogeneration systems small gas turbines or [[stirling engine]]s powered from natural gas produce electricity and their exhaust drives an [[absorptive chiller]].

A truck trailer refrigerator operating from the waste heat of a tractor's [[diesel exhaust]] was demonstrated by NRG Solutions, Inc. NRG developed a hydronic [[ammonia]] gas heat exchanger and vaporizer, the two essential new, not commercially available components of a waste heat driven refrigerator.

A similar scheme (multiphase cooling) can be by a multistage evaporative cooler. The air is passed through a spray of salt solution to dehumidify it, then through a spray of water solution to cool it, then another salt solution to dehumidify it again. The brine has to be regenerated, and that can be done economically with a low-temperature solar still. Multiphase evaporative coolers can lower the air's temperature by 50&nbsp;°F (28&nbsp;°C), and still control humidity. If the brine regenerator uses high heat, it also partially sterilises to the air.

If enough electric power is available, cooling can be provided by conventional air conditioning using a [[heat pump]].