人们曾多次尝试定义“被动式太阳能供暖系统”，但没有一个是完全令人满意的，因为此类系统的形式多种多样。国家标准局（NBS）1为住房和城市发展部（HUD）制定了一个定义:“被动式太阳能加热系统是集热器、蓄热装置和太阳能电池的集合以及txansfer介质，该介质将太阳能转换为热能，除太阳能外不使用任何能量来实现热能的txansfer。被动太阳系中的主要元素通常是某种形式的热电容。当检查目前使用的被动式加热系统时，发现基本元件通常是太阳能进入结构的方式，而不是储存方式。“引用:研讨会，ASHRAE交易，第83卷，第2部分，哈利法克斯，北卡罗来纳州。”

Many attempts have been made to define "Passive Solar Heating Systems", but none is completely satisfactory because of the wide variety of forms which such systems can, ttike. A definition formulated by the National Bureau of Standards (NBS)1 for the Department of Housing and Urban Development (HUD) states:"A passive solar heating system is an assembly of collectors, thermal storage device(s) and txansfer media which converts solar energy into thermal energy and in which no energy in addition to solar is used to accomplish the txansfer of thermal energy. The prime element in a passive solar system is usually some form of thermal ca:pacitance.When the passive heating systems now in use are examined, it is found that the prime element is generally the means by which solar energy is admitted to the structure rather than the storage means."