Indoor thermal environments in Chinese residential buildings responding to the diversity of climates

China has a diversity of climates and a unique historic national heating policy which greatly affects indoor thermal environment and the occupants’ thermal response. This paper quantitatively analyzes the data from a large-scale field study across the country conducted from 2008 to 2011 in residential buildings. The study covers nine typical cities located in the five climate zones including Severe Cold (SC), Cold (C), Hot Summer and Cold Winter (HSCW), Hot Summer and Warm Winter (HSWW) and Mild (M) zones. It is revealed that there exists a large regional discrepancy in indoor thermal environ- ment, the worst performing region being the HSCW zone. Human’s long-term climate adaptation leads to wider range of acceptable thermal comfort temperature. Different graphic comfort zones with accept- able range of temperature and humidity for the five climate zones are obtained using the adaptive Predictive Mean Vote (aPMV) model. The results show that occupants living in the poorer thermal environments in the HSCW and HSWW zones are more adaptive and tolerant to poor indoor conditions than those living in the north part of China where central heating systems are in use. It is therefore recommended to develop regional evaluation standards of thermal environments responding to climate characteristics as well as local occupants’ acclimatization and adaptation in order to meeting dual targets of energy conservation and indoor thermal environment improvement

Resiliency Analysis of Energy Demand System in Finland

Investigating the performance and productivity level of different energy consuming sectors in all countries is an inevitable action. This procedure will be conducted by comparing the energy input and the output of the system which is vital to ensure that the system is used properly. The proper utilization of systems will lead to more efficiency in the energy consumption section. One of the most important tasks in this type of study is the analysis of uncertainty indicators. The analysis and evaluation of uncertainty indices in energy consumption system is a tool that prioritizes the indicators in terms of importance and impact on each of the consumption targets. These consumption goals include energy, environmental, technical, economical, and social objectives. Ultimately, the output data of the uncertainty analysis will be very helpful for making the system more reliable and usable. In this study, we first introduced different sectors of the energy consumption system in Finland and examined each of these sectors in terms of physical and environmental goals. Then the uncertainty indexes in different sectors are extracted, evaluated qualitatively and quantified using the fuzzy logic method. Finally, indicators are prioritized based on the level of effectiveness and uncertainty. According to the results of this research, among 44 considered indices, the security of energy supply, carbon emission, equivalent annual cost, reliability, and political acceptability are respectively the most important indices for energy, environmental, economic, technical and social goals.fi=vertaisarvioitu|en=peerReviewed

Aerobic biodegradation of per-treated methyl tert-butyl ether by ozonation in an up-flow-fixed-bed reactor

Problem Statement: MTBE is a common pollution of environmental and has become an issue of considerable concern in recent years. It is not readily amenable to remove MTBE by conventional techniques in water treatment. In the present study, the feasibility of the continuous aerobic biodegradation of MTBE, was evaluated in an Up- Flow Fixed Bed Reactor (UFBR). Approach: The UFBR at a constant Hydroulic Retention Time (HRT) of 24 h was used as a biological process that receives the intermediates due to partial oxidation of MTBE. The UFBR coupled to ozonation process as a survey system after a primary operation phase that was necessary for creatory of an initial microbial film on the carriers. Residual concentration of MTBE and its major degradation intermediates were measured by gas chromatography. Aqueous concentration of ozone in the reactor and ozone average concentration in off- gas were determined according to the indigo blue method. The COD reduction and BOD5 to COD ratio were selected as biodegradability indexes. Results: Results showed an effective degradation of MTBE in the coupled ozonation-UFBR continuous flow reactor of ten days of operation time. A partial degradation of MTBE in AOPs increases its biodegradation The BOD5 to COD ratio increased from lowest (0.01) up to a maximum of 0.72 that corresponds to an ozone consumption of 0.62mg per each mg of COD initially present in the solution. The results showed when m. MolMTBEo/m. Mol(o3) = 0.611, the COD removal efficiency was 89% and as this ratio increased up to 1.25, the of COD removal efficiency decreased to 80%. 46-68% removal of the COD was needed before the mixture was considered biodegradable. The highest removal rate of MTBE, 82.91 mg day-l achieved through out the UFBR runs (87% removal efficiency, In this study, the removal efficiency of MTBE using integrated-process (ozonation followed biological treatment) was from 78.5-86.5%. In order to determine of biological removal rate of MTBE, another UFBR system used as a blank reactors. Results showed that the efficiency of the COD removal (by stripping with the biological degradation) was 5-8% which implies insignificant biological removal of MTBE without pre-ozonation. Solid produced in the proposed integrated process was 0.27-0.35 kg TSS kg-1 COD removed which is approximately in down range of conventional biological system (0.3-0.5 kg TSS kg-1COD). Conclusion: Present study showed that we can treatment of the polluted aqueous solutions to MTBE without microbial incubation used to integrated process. © 2009 Science Publications

Spatial configuration, building microclimate and thermal comfort

In this paper, the authors attempt to clarify the relationship between spatial configuration, building microclimate and thermal comfort through the investigation of a modern house in hot and humid climate with spatial diversity. First, the spatial configuration of the house was analysed in detail. The spatial geometric features, spatial boundary conditions, and human activities in the building were categorised. Secondly, field measurements were conducted to investigate the microclimate of the house. The air temperature, relative humidity and wind velocity were monitored on typical summer days. Thirdly, a dynamic thermal simulation was performed to predict the thermal comfort performance of the building over the period of an entire summer. The simulated results were compared with the measurements, and the adaptive thermal comfort approach was used to evaluate the thermal comfort. The modern house studied was found to have a varied spatial configuration, similar to local vernacular buildings, which produces diverse thermal environments in the building. The microclimate of this specific building could provide considerable thermal comfort for the occupants in summer under the local climate conditions, although thermal comfort cannot be achieved through free-running model in the hottest days, mechanical cooling or mixed model are needed

Oceanus.

v. 25, no. 2 (1982

Indoor environmental assessment: comparing ventilation scenarios in pre- and post-retrofitted dwellings through test cells

In the next few years, outdoor temperature is expected to increase significantly as a result of climate change, a noticeable phenomenon, especially in the Mediterranean. In this future scenario, ventilation is a low-cost and useful strategy for tackling indoor overheating, mainly in energy-poor housing buildings. This research assesses the influence of different ventilation systems, air rates and schedules on the thermal comfort and indoor air quality of a residential retrofitted space when compared to an un-retrofitted environment, through test cell measurements. To do so, the methodology combines on-site monitoring with numerical models, simultaneously analysing both spaces under the same climate conditions. Results obtained show barely perceptible differences between the implementation of a mechanical ventilation system and a natural one, when it comes to thermal comfort in spaces with low thermal inertia, highlighting the clear advantage of energy and economic savings of the passive system