Nanomaterials describe, in principle, materials of which a single unit is sized (in at least one dimension) between 1 to 1000 nanometres (10−9 meter) but usually is 1 to 100 nm (the usual definition of nanoscale).
Heating, ventilation and air conditioning (HVAC) systems account for approximately 35 % of the total energy spent in residential and commercial buildings. New nanotechnology will significantly reduce this massive energy use.