Air

The breath of a house has a great effect on its inhabitants. Heating, cooling, ventilation and filtration are an important part of a healthy and comfortable home. This author may emphasize heating over cooling as no one has ever had to replace exploded plumbing due to their air conditioner failing in the summer.

Heating

 * Composting heater

The composting heater stack uses a central core of excriment and wood chips surrounded by a larger ring of similar material with a coil of tubing wound between the two zones. A lower inlet and upper outlet port direct to and from a liquid to air heat exchanger such as a car radiator, and a pump to drive fluid movement if convection is insufficient.
 * Wood stove

In areas with an abundance of wood, a simple stove is very practical. More advanced management and air circulation systems can provide much more efficient burn, and a liquid to air heat exchanger pulling heat off the exhaust of the stove can also add greatly to the overall output.
 * Wood gas

Generator/internal combustion engine running wood gas can provide huge heat output as well as power - capturing exhaust gas heat energy provides an excellent source.
 * Thermal mass

By partially burying structures or integrating large masses of earth, significant heat can be banked, or drawn from the earth's ambient warmth.
 * Solar

Effective design features can maximize solar absorption, minimizing heating needs.
 * Solar intake warmers

Using recycled aluminum cans and black paint one can make an intake tube or recirculator that collects solar energy on the surface of the cans, warming the internal airstream.

Cooling

 * Vent walls

Recent design work in the third world shows great results using recycled materials to make walls with air inlets on one side and outlets on the other, with the inlet size being much greater than the outlet size, apparently creating a cooling effect.

Venting

 * Modular air plenums integrated with modular building block segments allow for easy and extensive air circulation

Filtration

 * UV bulbs
 * Mechanical filters
 * Plants