Theoretical Research On Envelope Insulation Effect For Residential Buildings With Compartmental And Intermittent Energy Consuming Method

Building energy efficiency design method in severe cold and cold zones is mainly based on the experience of the foreign building energy efficiency,as the energy use pattern are similar to each other,thus has obtained good effect.By contrast,the climate characteristics of China hot summer and cold winter zone is special,and the energy use pattern of residential building in this area is very different from the northern area,the main two different characteristics bring the difference of energy consumption model:compartment energy consuming method lead to energy exchange not only exist between the indoor and outdoor,but also exist between the energy using space and no energy using space;intermittent energy consuming method results in energy storage and release in six sides envelope happened in the whole intermittent energy consuming process,and the heat storage of wall material is more than one thousand times of air under the same volume,this passive cooling and heating sources will seriously affect energy consumption.The choice of internal or external insulation for exterior wall and balance setting thermal performance of building envelope and partition,is very important to effective distribution of incremental cost and effectively obtain energy saving effect in this background.But there exists big difference between the specified energy use condition in the design code and actual energy use conditions in hot summer and cold winter zone,makes a huge difference between the energy saving rate according to the existing design method and the actual energy saving effect,leading to the enclosure structure energy saving incremental cost obtain little effect in this region.This problem needs to be fundamentally resolved.For a comprehensive understanding of residential building occupant behavior in hot summer and cold winter zone,the characteristics of climate in this zone was firsty analyzed.Then conducted large scope of questionnaire survey and a small scale site test about air conditioning use behavior in Hangzhou,a typical city of this climate zone.Results show that more than ninety percent of hangzhou residences adopting compartment and intermittent energy use mode,the actual heating and cooling period is different with the design code.According to actual meteorological data of different cities to obtain heating and cooing calculation period would bring energy consumption simulation result closer to real fact.Take the log of meteorological data from 1971 to 2000 as foundation,the five-day-moving average method was adopted,the heating and cooling calculation periods of nine typical cities in hot summer and cold winter zone was concluded.Based on the actual construction model,the DesignBuilder building energy consumption simulation software(its core is EnergyPlus)was used to dynamic simulating annual load of this construction,to research the energy saving effect of different heat preservation measures under compartment and intermittent energy use effect.Results showed that the energy-saving effect of exterior wall external insulation is better than that of internal insulation under the standard continuous energy consuming way;in a fixed intermittent energy use schedule,the energy-saving effect of exterior wall internal insulation is better than that of external insulation,and exteral insulation may cause anti-insulation phenomenon in cooling condition.The anti-insulation phenomenon in cooling condition for external insulation is greatly affected by the window to wall ratio(WWR)and cooling set temperature.Under the actual night cooling condition,the critical anti-insulation WWR for external insulation is 30%,the critical anti-insulation set temperature is 26?,the higher the two value,the more likely happen the anti-insulation phenomenon.The energy-saving effect for partition insulation under different energy use method was calculated.Results show that under the standard continuous energy consuming way,adding insulation to partitions will not reduce energy consumption,it will slightly increase annual energy consumption;under the compartment and intermittent energy use method,energy consumption significantly reduced after adding insulation to partitions.Compartment and intermittent energy use in residential buildings closely related to the random characteristic of occupant behavior.In this paper,field test for six typical families of hangzhou has been conducted for three years.Applying the test results to verified the accuracy of the calculation results from DeST occupant behavior simulation software,results showed that compared with the original software,cooling load calculation error from DeST embedded with occupant behavior module is decreased by 13.8%and heating load calculation error is decreased by 94.1%.Applying the original software with tolerate temperature setting function to analyzed annual energy saving effect of internal and external insulation under different tolerate temperature grade.In the case of low and intermediate tolerate temperature level,the internal insulation had better insulation effect;in high tolerate temperature level cases,the external insulation had better insulation effect;the critical tolerate temperature point at which internal and external insulation configuration had the same energy-saving effect is 31.8? for summer and 13.4? for winter.Applying the DeST embedded with occupant behavior module to simulate the internal and external insulation energy-saving effect under two kinds of actions,results showed that the internal insulation saved more 2.78%energy than external insulation under the economical occupant behavior,the internal insulation saved more2.90%energy than external insulation under the practical occupant behavior.Based on the simulation analysis conclusion,a three-year empirical study on the energy saving effect of different insulation configuration for a real building was conducted.Results showed that the wall heat storage is 29 times the indoor air heat consumption.As the insulation installed in the internal side of exterior wall,the heat storage of the wall was reduced,therefore the internal insulation configuration cost lower energy consumption.Through measuring each temperature point of wall profile and the air,it can be seen that the outdoor air temperature drop during the night cooling condition,the wall temperature is higher than the outdoor temperature,when insulation layer was put in the outer side of the wall,the process of heat dissipating to outdoor was stopped and thus produce the phenomenon of anti-insulation.The energy-saving effect of partition insulation was greatly affected by adjacent room energy using condition.Putting forward a kind of energy saving design method for residential buildings with compartment and intermittent energy use pattern in the hot summer and cold winter zone.Suggested thermodynamic parameters value of building envelop,energy using time and A/C control pattern was given,so that the A/C load of the reference construction would be more close to the actual building.Put forward a kind of unit design method for building energy efficiency,introducing the idea of balanced design,taking room as a unit for energy-saving design.Calculating the optimal thermal insulation layer thickness of building envelop and the recommended value under the particular unit model was given.Simulation results showed that the "energy saving 50%" architecture ruled by region code,can only save 17.12%in recommended compartment and intermittent A/C operating conditions,which was far less than the theoretic 50%energy saving rate of.Building which applied the unit design method costed less building insulation materials than the "energy saving 50%" architecture,but will save 13.29%more energy.