Passive Design

Passive design usually refers to a collection of design techniques that reduce the need for mechanical systems. These are passive solar design, natural ventilation and day lighting. Passive solar design aims to use the natural resource of sunlight to reduce heating loads by positioning windows, skylights and shutters to control the amount of direct solar radiation reaching the interior spaces themselves, and to warm the air and surfaces within the building. The use of South-facing windows and a high-mass floor is an example of this.

Natural ventilation refers to the process of supplying and removing air through an indoor space by natural means. There are two main types of natural ventilation occurring in buildings: wind driven ventilation and stack ventilation. Stack effect ventilation works on the principle that warm air rises and cool air sinks. In order for a building to be ventilated adequately via stack effect the inside and outside temperatures must be different so that warmer indoor air rises and escapes the building at higher apertures, while colder, denser air from the exterior enters the building through lower level openings. Wind driven ventilation relies on the wind on the building to create areas of positive pressure on the windward side of a building and negative pressure on the leeward and sides of the building which drives air flow through its apertures.