comfort zone of cold climate in iran

the process of constructing buildings is a complex activity, which has a variety of impacts on our environment, society and economy. buildings provide shelter, encourage productivity, embody our culture and can create a great legacy for the future while at the same time establishing links with the past. but they also consume a huge share of our land, energy, water and material resources. regarding the environmental factors, a built form is an artefact that acts as a transformer of the environmental conditions which are very often unsuitable for human life. buildings do not control climate which, apart from the wind or sun shadow that they may cast, remains largely unaffected by them. but within, the building dose modifies the climate, creating internal conditions that come closer to those which the occupants find most comfortable. on the other hand there is a growing awareness and concern about the impact of human activities, such as industry, transport, and agricultural, on the earth’s environment. issues of global warming, climate change and ozone depletion are now common features of discussion. linked to these topics are green issues and sustainability. it is not so well appreciated that for most countries the key contributors to environmental impact are buildings. the energy used to heat, light and ventilate buildings consumes nearly 50% of all the energy generated by a country. buildings will stand for normally at least 70 years, and are obviously consuming energy for all of that period. a poorly designed, energy inefficient building has a potentially very long term impact, both on the building users and the environment. however, for a best result in architectural design, designer should attention to climatic condition on place in question. according to different climatic condition of iran, it is surly needs to some consideration and revises the architectural design. climatic consideration of buildings design in the cold climate is important. in this climate, since summer is very short and most of the times of winter air temperature are well below the comfort temperature, the main point is how we can find a proper solution for this difficulty. thus, the main aim of this paper is to show how designer can be able to reduce the energy use in buildings by his/her design.as a sample for present study, climatic data of tabriz is under consideration. tabriz is one of the cold cities of iran. this city is mostly cold with the low day temperatures of 1?c to maximum of 10?c or even less. nights are very cool and the temperature dropping to the 0?c or less than it. six or sometimes seven months in the winter are periods of rather harsh conditions of cold. tabriz is selected for thermal analysis based on two software, first ashrae comfort win, second meteonorm and in the other hand based on climatic data of the city for period of 10 years.the results show thermal crisis during cold periods, but we can achieve to reduce the energy use by passive systems. although designer needs to active equipments in autumn and winter.