solar, low-cost building programs. Remaining problems are:
a.) the necessity to incorporate additional thermal storage to limit swings, and b.) integration of auxiliary heating systems into the building with minimal redundant construction.
Plenum floors, in use here since WWII, have gained acceptance as highly economical systems for thoroughly integrating the storage and distribution requirements of passive design. My first plenum floor residence (1975) used industrial roof decking to form the "mini -ducts" for air distribution and other similar residences have followed. The charging of the slab from below as well as from above increases the storage efficiency of the masonry slab allowing reduction in the amount of additional storage usually necessary in such buildings Twenty-one such systems have been completed, and additional projects are under construction'. The lay-outs have ranged from the simplest rectangular forms to complex angled schemes with elevational transitions, proving the system to be most adaptable.
Construction details and performance results are discussed. Costs are compared in a general fashion to other plenum floors and conventional systems. .....