Analysis of heating duration and heating load of multi-span greenhouse in China

Using architectural design standard as a reference, the climatology method of five-day sliding average was adopted to calculate the durations of daily average temperature less than many given temperatures, to compare these calculated durations with the actual heating periods of multi-span greenhouse in China, the heating duration of multi-span greenhouse was determined. The heating load in China was also obtained by adopting Japan's degree-hour method. The results are as follows: 1) The determined heating period, which was obtained by duration of daily average temperature less than 10°C of local 30 years' daily temperature, is in good agreement with that of matter-of-fact, and it varies from zero at the southern part areas to 365 days at most areas in Qinghai province and Tibet Autonomous Region; 2) The maximum coal consumption occurs in January, next does in December and February, by calculation the average coal consumption in January is 30% of whole year in north China, more than 20% in December and less than 20% in February. There are significant differences within different areas on the annual energy consumption. The calculation of heating duration and energy consumption can provide basis for on standardized heating-design as well as reference for the energy-saving for the multi-span greenhouse.