Structure and Principle of Energy-Saving Solar Greenhouse in Sihu Area of Hubei Province

In winter the climatic characteristics in Sihu Area has such properties as the solar height angle to be higher, sunshine time to be shorter, and in spring precipitation to be more than those of north China. Sunshine time becomes primary obstacle factor for developing heliogreenhouse. In oder to design and manufacture energy saving heliogreenhouse in Sihu Area, some structures and princples were taken into consideration such as ① The light environment was designed by the roof angle >14°,angle of elevation of back slope >40°, front roof forwarded to south, the roof height 2.8 m, the back wall hight 1.8～2.0 m, the proportion of height to span 1∶2.0～2.4. ② Temperature environment was designed by span 6～7 m, the ratio of front slope to back slope 5～6∶1, heat preservation ratio 1, sunshade ratio 1∶1.73. ③ The material was selected with back wall to be inter brick wall+hollow layer +brick-wall+straw and soil layer, transparent material with durable polyvingl chloride (PVC) film, thermal insulation material of front roof with straw mat. ④ The measures of raising temperature and increasing illumination was taken with installed oidine tungsten lamp and “><” shape flues in back wall.