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Notes to building standards: the role of sunshine time in cold days

DailyBird Culture 2021-10-08 1 0

with the development of social economy, there are more and more high-rise buildings in the city. Of course, it is good to improve people's living conditions, but there are also problems, that is, the high-rise houses affect the daylighting of other kinds of houses around. Therefore, the state stipulates that the cold day is the standard day for determining the sunshine time. Let's understand now, The effect of sunshine time on cold days.


the great cold day is the last of the 24 solar terms. Its time is around January 20 every year. Like the small cold solar term, it is a solar term reflecting the cold degree of the weather. In China, the cold day is the standard day for measuring the sunshine time and the indoor daylighting time of residential buildings. The so-called sunshine standard in


refers to the time when the external windows of the building get full sunshine within the effective sunshine time range of the specified sunshine standard day (winter solstice or cold day) in order to ensure the sanitary conditions of the indoor environment and determined according to the climate area, city size and use nature of the building. According to relevant national specifications, the residence shall meet the requirements that the effective sunshine of the room of the sheltered residential building on the cold day shall not be less than two hours.

sunshine standard day has a changing process in China. Because the winter solstice is the shortest day of sunshine in a year, it was first recognized as the winter solstice day of no less than two hours. However, later, the investigation of relevant departments found that this standard is generally difficult to meet in some cities because of high latitude and dense urban buildings. Therefore, it is changed to take the cold day as the date to determine the sunshine time. If the cumulative daylighting of the house on the cold day is less than two hours, corresponding compensation can be claimed. According to the national regulations of


, the distance between high-rise residential buildings and various residential buildings behind them shall meet the requirement that the effective sunshine time of sheltered residential buildings on a cold day shall not be less than 2 hours; In the old area reconstruction project, the new residence shall meet the requirement that the effective sunshine time on a cold day shall not be less than 1 hour. The minimum distance between high-rise houses and various houses behind shall not be less than 30m. On the cold day of


, at least one room of each house gets sunshine for more than or equal to 2 hours. In the standard, the sunshine standard day is a cold day, the sunshine calculation unit is each house (in household), and the sunshine duration is 2 hours. Due to the increasing building density in the city, the sheltered buildings are generally sheltered by multiple buildings, so the time to obtain sunshine is often discontinuous.

at the same time, in order to ensure the quality of sunshine, the residential area design code defines that the effective sunshine time zone corresponding to the cold day is 8:00 to 16:00. In a house, individual windows may not meet the sunshine standard, but if one window in a house meets the cold day for 2 hours, the house will meet the sunshine standard.


you may also like: what does huinantian mean? Quickly understand huinantian traditional Chinese medicine talking about great cold health preservation: repair kidney qi. At that time, four kinds of disease removing porridge in the great cold solar term were hot, delicious and healthy. Drink kidney nourishing tea in the great cold. It is not dry or greasy. It is very healthy

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