Review and development of the contribution ratio of indoor climate(CRI)

An indoor thermal environment is affected by various heat elements,such as heat transfer through walls,solar radiation,and heat emissions from people,lighting and equipment.To promote both local thermal comfort and building energy efficiency,demand-oriented ventilation(such as personalized ventilation)has been developed.When using this method,a good understanding on indoor temperature distribution becomes necessary.For this purpose,an index known as Contribution Ratio of Indoor Climate(CRI)has been developed through extraction from the calculation results of Computational Fluid Dynamics(CFD).This index can be used to analyze the independent contribution of each heat element to indoor temperature distribution.In this paper,a complete and detailed introduction of the CRI is given,including its basic premises,definitions,and mathematical meaning.Particularly,calculation method of the CRI in natural convection airflow fields is further developed.Two cases(forced and natural convection airflow fields)have been carried out in different scenarios,with results showing that the CRI of a heat source had higher values in the area around itself.Also,it had a larger influence range in forced convection airflow field because of the convective airflow,while relatively larger CRI values only appear in the area above the heat source in the natural convection airflow field because of the heat plume.As a useful index for understanding the form of indoor temperature field,the CRI has guiding significance for regulating air-conditioning/ventilation systems to build better indoor thermal environment.

The Thermal Comfort and Hygrothermal Performance of the First Certified Passive House in Estonia

This study presents the thermal comfort and hygrothermal performance of building envelope of the first certified passive single-family detached house in Estonia.Temperature and humidity conditions were measured from different rooms and building envelopes.This article presents analysis of measurement results during the first year after construction.Results showed high room temperature,achieved mainly due to large windows with southern exposure and the small heat loss of the building envelope.High indoor temperature decreased the indoor RH(relative humidity)to quite low levels.Even the RH was low,the moisture excess was high indicating that the design of PH(passive houses)indoor humidity loads cannot be decreased.Humidity in the externally insulated cross-laminated timber panels was observed to be high,caused by drying out of the constructional moisture and the high diffusion resistance of the wood fibre sheathing board.That caused water vapour condensation and risk for mould growth.In conclusion,while planning buildings with high-energy efficiency,more focused attention should be paid to the performance of the building service systems and moisture safety already in the preliminary stages of design.

RE-CONSTRUCTING THE COMFORT ZONE

This paper deals critically with the way people’s“comfort zone”is conceptualized within the indoor climate context.It draws attention to the emergence of international building guidelines and standards which engineers and architects use when designing a building,that describe the“comfort zone”as a narrow,optimal,steady state of“neutrality”of the human body with its immediate,physical environment.Scientists from different fi elds have been recently suggesting that this conceptualization is unsustainable and based on false assumptions about the relationship and interaction between people and their environment.In order to reconcile sustainability with the built environment’s demand for comfort,the practitioners of sustainable architecture and design as well as policy-makers may greatly benefi t from understanding people’s current social practices,values and visions with regard to comfort;to enable people’s acknowledgement and ability to adapt to sustainable,new ways of operating and managing one’s indoor environment,it may be of advantage to be able to account for the socially accepted,everyday(non-)sustainable actions relating to one’s comfort which can be,in some cases,rigorous and resistant to change.This paper outlines a case where researchers have empirically studied the building inhabitant’s own judgments and values and his actual experience with regard to comfort in everyday life.In parallel qualitative and quantitative data within the user’s context,in this case the building inhabitant’s context,were collected while researchers took the role of the observer-as-participant and followed Danish families how they practice“comfort”during an ordinary day at home,work and school.From the data,an interpretation about the above phenomenon is illustrated in detail showing how situational,temporal and idiosyncratic“ordinary”people’s values and decision making relating to their personal management of the indoor environment are,and the relevance for sustainable building design is demonstrated.The results presented underline the signifi cance of looking beyond e.g.measuring physical parameters and following international building guidelines,when being on the search for comfort“factors”and adaptive opportunities in future sustainable building design.

多学科和多行业协同破解建筑室内空气质量难题

Healthy building is a new trend after green buildings in the world."WELL"was launched as the first guideline for healthy buildings in 2014 in USA.In 2017,China Healthy Building Assessment Standard was launched.Good indoor air quality is an important part for healthy buildings.The score of indoor air quality accounts for nearly 25 in the total score(100)in Healthy Building Assessment Standard(T/ASC 02-2016).The indoor air quality items in the standards are mainly based upon China Indoor Air Quality Standard(GB/T 18883-2001).However,the target indoor air pollutants in the both standards(T/ASC 02-2016 and GB/T 18883-2001)are not determined based upon the indoor air quality investigations in China.In order to revise the China Indoor Air Quality Standard(GB/T 18883-2001)and improve or develop the relevant indoor air quality control techniques,it’s necessary to know the important and unsolved problems in indoor air quality control in China.From them,the important scientific problems and key technical problems in China can be identified,and the gaps between the control demands and the levels of the related industries in China can be recognized.Then,various control approaches and strategies can be developed effectively.For this purpose,we present a series of important and unsolved problems in indoor air quality control in China:Identify the target indoor air pollutants and the corresponding thresholds based upon China’s indoor air quality situations,develop energy efficient engineering approaches to simultaneously control indoor air climate and quality,and develop the approach of scientific evaluation for indoor air quality control effect.The important scientific and key technical problems behind them are:The method of determining the target indoor air pollutants,the method of determining the thresholds of the target indoor air pollutants,the principle and method to overall control of indoor air climate and quality,the method of scientific evaluation for indoor air quality control effect not only based upon the concentrations of the target indoor air pollutants but also based upon the human health response.We are carrying out a national research project whose title is"study on fundamental problems and key technical approaches in indoor air quality control".Based upon its research advance,we put forward a framework and understanding of solving the aforementioned problems:(1)Determining the target indoor air pollutants based upon the burden of diseases of indoor air pollutants in China.In the study,the burden of diseases of all target indoor air pollutants is obtained so that the overall burden of diseases of indoor air pollution can be roughly estimated.It’s a quantitative index to show the importance of indoor air quality problems in China.(2)Determining the corresponding thresholds of the indoor air pollutants based upon the control feasibility and the health benefit.The healthy benefit can be evaluated by the reduction of burden of diseases of the target indoor air pollutants which can also be equivalent as the reduction of economic loss.(3)Developing inverse problem and variation method to identify the optimal control systems and operative strategies.It’s an original novel approach for indoor air quality control.(4)Developing some partial space and/or partial time control approaches for indoor air quality.(5)Developing novel evaluation method for control effect by using biomarker-based techniques.(6)Narrowing or even removing the gaps between the indoor air quality control related industries.The indoor air quality control standards in those industries shouldn’t conflict each other.(7)Applying various newly-developed sensors and big data techniques to understand the links between the indoor air quality and human health response.New on-line monitoring sensors with acceptable precision,together with some new big-data analysis methods are strongly needed.To tackling the above problems which are related to many disciplines,collaboration among multi-disciplinary research and industries is very important.