| Gannan is a Tibetan autonomous prefecture in China that is known for being the "window to the Tibetan plateau" and the "springboard for Sino-Tibetan culture." The area attracts many monks who come to practice and live here.However,the indoor thermal environment of the buildings,which are mainly made of rammed earth and wooden planks,is poor due to the low average annual temperature of 2.4℃ and a lack of effective central heating measures.This study focuses on enhancing the indoor thermal environment of buildings for special groups of people while reducing building energy consumption.Additional sunspace is seen as an effective passive heating strategy,with high application prospects.The study uses the Zhaxi Monastery in Tang Ga’ang Township,Xiahe County,Gannan Autonomous Prefecture,Gansu Province,as an example and explores the application effect of additional sunspace on monastery buildings through field tests.Energy Plus,an energy consumption simulation software,was used to simulate the hour-by-hour air temperature of the case building throughout the year.The PMV-PDD and a PMV indicators were used to evaluate the indoor thermal environment of the additional sunspace building.The sensitivity analysis method was used to explore the degree of influence of each construction factor of the additional sunspace on indoor thermal comfort and energy consumption,respectively,and to optimize the highly sensitive factors.The empirical simulations and sensitivity analysis show that:(1)The additional sunspace significantly improves the winter indoor temperature of the monastery in Gannan,with a maximum temperature of 30℃ at night in winter under the condition of extensive wood burning.(2)Without additional heating facilities,the annual average temperature in the room ranges from 11.7℃ to 19.7℃,and 2,031 hours(46% of the winter)are still in the thermal discomfort zone.(3)The thickness of the roof insulation has the most significant effect on thermal comfort in this zone,while the thickness of the rammed earth on the roof has the greatest effect on energy consumption.The construction factors of the building itself had a greater influence than the clear glass elements of the sunspace.(4)The ideal design thickness of the rammed earth roof layer is 1.1m-1.2m,and the design range for insulation thickness is 10-90 mm,but from an economic point of view,10-40 mm is optimal.(5)The orientation of the additional sunroom is recommended to be south,while the southwest orientation has the lowest energy consumption.When optimizing the building envelope,the highest energy saving rate of 5.01% is achieved by using 520 mm thick heavy self-insulating material.With the same insulation layer thickness,PU has the highest energy saving rate and the lowest a PMV value,PVC has the lowest energy saving rate and the highest a PMV value.The use of an 800 mm thick layer of raw earth + straw-lime compacted plywood is a low carbon and efficient way of constructing walls.For a given roof rammed earth layer thickness of 550 mm,a roof insulation layer thickness of 80-90 mm is appropriate;for a given 50 mm roof insulation layer thickness,a roof rammed earth layer thickness of 800-900 mm is appropriate.With the addition of a roof sunroom,the overall energy consumption of the building drops to 5829.23 k W/h,an energy saving rate of up to31.5%.This study can provide architects with design decision support for the thermal environment control of passive houses in Gannan.The study of the indoor thermal environment of Tibetan Buddhist dwellings also enriches the thermal environment results for different residential building types.Additionally,it provides technical support for the realization of carbon neutral carbon peaks. |
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