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Abstract Ventilation is commonly thought to be helpful for improving indoor air quality. However, this may not be true when the outdoor air is polluted. For example, in the event of fog or haze in developing countries, outdoor particulate matter (PM) can be drawn into rooms by ventilation systems. In such circumstances, ventilation must be accompanied by indoor particle filtration. This investigation incorporated a particulate-filtration model into the EnergyPlus software. The validated software was then used to evaluate ventilation together with indoor particle filtration in a typical Chinese residential apartment. The ventilation modes included natural, mechanical, and hybrid ventilation. Transient air change rate, indoor CO 2 and PM2.5 concentrations, air temperature, annual energy consumption, and utility costs were solved. For the mechanical systems, demand-controlled outdoor air rates and clean air delivery rates (CADRs) that ensure acceptable indoor air quality were also solved. It was found that indoor particulate filtration must be utilized in northern Chinese dwellings. A combination of natural ventilation and portable demand-controlled particulate filtration has the lowest operating cost, but the ventilation rate may occasionally be insufficient. Among the mechanical ventilation modes, decentralized systems operating only during the occupied period have great potential to minimize utility costs. Mechanical ventilation in demand-controlled operation and its hybrid with natural ventilation can further reduce energy consumption. Highlights • A particle-filtration model was incorporated into EnergyPlus. • Demand-controlled outdoor air rates and CADRs ensuring air quality were solved. • Natural ventilation plus portable filtration cost least but provide insufficient outdoor air. • Decentralized mechanical systems operating only in the occupied period save utility costs. [ABSTRACT FROM AUTHOR]

Occupants’ interactions with windows not only influence energy consumption but also influence indoor air quality of the buildings. There are many factors that affect occupants’ behaviors on windows opening and closing, such as the arrival of occupants, meteorological condition, indoor thermal environment and air quality. In this study, we tended to investigate what and how environmental factors influence residential occupants’ window opening behavior in spring in Beijing, China. The environmental factors concluded air temperature and relative humidity of indoor and outdoor, indoor CO2 concentration, outdoor PM2.5 concentration and outdoor wind speed. We conducted a field study in 9 naturally ventilated residences in Bei-jing during spring. Environmental parameters mentioned above and window status were monitored. A stochastic model of occupants’ window opening behavior was established via multi-variate linear logistic regression. The results indicate that influence of the all 7 variables on window opening behavior was significant. The multivariate linear logistic regressed model with normalized variable for the window opening behavior prediction is [ l o g i t p = l o g ( p 1 − p ) = 2.11 C C O 2 , n o r + 2.096 T i n , n o r − 5.277 R H i n , n o r − 3.547 C P M , O , n o r + 5.71 T o u t , n o r + 4.512 R H o u t , n o r − 2.158 V s − 1.844 ] [ABSTRACT FROM AUTHOR]

The buildings sector, being a leading energy consumer, would need to lead in conservation efforts as well. There is a growing consensus that variability in indoor conditions can be acceptable to occupants, improve comfort perception, and lower building energy consumption. This work endeavours to scrutinise and summarise studies that examined human thermal and comfort perception to such variations in the indoor environment: spatial transients, non-uniformities, and temperature drifts. We also briefly discuss personalised comfort systems since they work on an occupant's micro-climate and create non-uniformities in the indoors. Perusal of works done on effect of non-thermal factors on thermal comfort, point to the need for synchronizing the overall indoor environment's quality – in terms of décor, air quality, lighting etc. – to improve occupant thermal comfort. Essence of the overall discussions come out to be that indoor thermal environment can be variable and still agreeable, implying existence of energy saving avenues, hitherto precluded from earnest consideration. [ABSTRACT FROM AUTHOR]

The aim of the study was to develop models for energy planning for an air supported sports hall by analyzing different energy efficiency possibilities. This is a very specific building type suitable for sport activities in cold climates. The observed hall was operated when outdoor temperature was under 5 °C, while the most common measured indoor air temperature was 8 °C during the year. Neither indoor nor outdoor temperature influenced the overpressure. Based on the measurements, the specific annually heating energy use was 75 kWh/m 2 . The results showed that improvement in the hall insulation would not give a significant effect on the heating use. The analysis of energy efficiency measures showed that air recirculation has the greatest effect on total energy use and the air recirculation could give an energy saving of 27% when 50% of the indoor air was recirculated. The results might be used to calculate heating energy demand for different operation scenarios in the air supported halls. The results give a simple tool to size the heating coil in the AHU and for energy planning for similar halls. The study gave very specific and unique data on energy use in sport halls in cold climate. [ABSTRACT FROM AUTHOR]

Solar control films could be a suitable way to reduce cooling energy consumptions and to reduce discomfort conditions in existing glazed buildings, but their performance is often evaluated by numerical analysis only. In this paper, an integrated thermal-energy and lighting characterization of solar control films performance was carried out by full-scale experimental setup and numerical analysis: two similar offices, with and without solar control films, in a multifunctional building in moderate climate were investigated. Solar control films strongly reduced the incoming solar radiation (about 60%), not depending on the external solar radiation. During springtime, window films allowed a reduction of about 2–3 °C of the indoor air temperature, during sunny days; they influenced also the globe thermometer temperature: with window coatings, it is almost equal to air temperature, whereas with conventional windows, it is about 2 °C higher, especially in the afternoon, due to the contribution of glass surface temperature (which is 10 °C higher). Furthermore, the contribution of artificial light increases, especially on cloudy days, because the daily average illuminance level was lowered by about 59%. Finally, preliminary simulations showed that the cooling energy demand decreases of about 29% thanks to solar control films, but at the same time the energy demand for heating increases of about 15%. [ABSTRACT FROM AUTHOR]

The aim of the present paper is to analyze a building optimization and control (BOC) algorithm which is implemented in the existing building energy management system (BEMS) of the Saint George Hospital in Chania, Greece. The developed algorithm consists of predicted models for outdoor/indoor air temperature using artificial neural networks, multi-step optimization using genetic algorithms and Real Time control using fuzzy techniques. The algorithm is developed in Matlab™ environment and is implemented to the existing BEMS of the Hospital, using a specialized web-based energy management and control system (Web-EMCS). The implementation of the BOC algorithm is realized by developing a “.net assembly” code, which interconnects the Web-EMCS with the existing conventional hospital's BEMS, without the need of Matlab™. The annual primary energy efficiency achieved is almost 36%. [ABSTRACT FROM AUTHOR]

Indoor air temperature monitoring is a basic activity giving useful information in many fields such as human thermal comfort, food preservation conditions and energy simulations. The collected data can help the room management and, their elaborations, can improve energy-efficient building design. The survey equipment installation in an indoor space – sensor number and positions, record frequency – is a delicate procedure depending on several conditions related to the specific room. Nevertheless specific installation procedures are nor defined or codified in the scientific literature. This study aims at the definition of a temperature survey method, both accurate and cost-effective, able to quantify and maximize precision and accuracy of the temperature monitoring in indoor spaces, through an experimental temperature test carried out on a wine-aging room of an Italian wine farm. The method allows to identify homogeneous temperature zones, the number of sensors to be installed and the proper data recording frequency, based on the specific needs of the process under study. This method is experimentally validated by means of a test carried out on a wine-aging room. [ABSTRACT FROM AUTHOR]

The control systems of conventional heat pumps have an input of refrigerant temperature at the evaporator outlet to maintain superheat at proper level. In order to develop a control method that can be used to achieve better indoor thermal comfort and energy efficiency at a low cooling load condition than the current control method, a new method of the evaporation pressure control based on the evaporator outlet pressure reading (EPCP) was developed. The changes in the stability of indoor air temperature and power consumption were measured while changing the compressor frequency in accordance with the new control method. Compared with the evaporation pressure control based on the evaporator outlet temperature reading, the EPCP control method appeared to improve the stability of room air temperature or occupant thermal comfort significantly. [ABSTRACT FROM AUTHOR]

Abstract: Experimental research carried out on two types of buildings that are the examples of vernacular architecture in Southern Italy, namely the Sassi of Matera and the Trulli of Alberobello are outlined in this paper. Experimental measurements on thermal properties, energy performance and hygrothermal indoor comfort were carried out to validate the numerical code provided by DesignBuilder/EnergyPlus that was used to investigate the buildings on a yearly basis. The very high thermal mass of the building structures give rise to a quasi-constant seasonal indoor temperature with no need for air conditioning in the mid- and peak-summer seasons. The seasonal thermal storage can almost guarantee near the comfort levels using simple heating systems during the cold season. [Copyright &y& Elsevier]

Abstract: The number of attempts by researchers to reduce building energy consumption has increased, ever since global warming became a serious issue. In this trend, a relatively new approach of air distribution, underfloor-air-distribution system (UFAD), has been widely used in new commercial buildings. This technique is simply accomplished by supplying air through a raised floor using different types of distribution configurations and outlets. In UFAD, the air is directly supplied to the occupants’ area (occupied zone) causing occupants plumes and zone heat load stratify to the upper layer of the zone (unoccupied zone), which are later extracted from return points at high level. This flow pattern gives UFAD the advantage of using less energy than a conventional air-distribution system, ceiling-based air distribution (CBAD) due to lower pressure drop and lower air flow rate. This paper investigates the effectiveness of UFAD systems in commercial buildings for various types of application and at different air supply temperatures in a hot climate (The State of Kuwait). The findings show that UFAD has a significant saving of energy compared to CBAD (∼30%); in particular with high ceiling building types, as well as providing satisfactory comfort conditions for the occupants. Ultimately, more investigations should be done on conventional building heights (offices) to optimize the utilization of thermal stratification at design and operation stages. [Copyright &y& Elsevier]

Many New Zealand residential homes suffer from poor indoor air quality (IAQ). Cold, damp and mould-ridden homes can cause severe respiratory health problems. Poor IAQ can arise due to inadequate insulation and ventilation and is compounded when dwellers cannot afford to heat their homes during colder months. Grandfathering of standards means many New Zealand houses have single glazed windows and insufficient or no wall insulation. These have become mandatory for newly built houses since 2016 under the New Zealand Standard NZS4246:2016 Energy Efficiency. This paper aims to present the results of modified ultraviolet germicidal irradiation (UVGI) lights-dehumidifier coupled with two different types of filters (carbon-fibre or polyester). The modified devices were designed to improve ambient air temperature by removing moisture, particulate matter and reducing mould and bacteria growth in a room. Seven different scenarios were investigated, which include combinations of UV light and filtration. The results showed that the UVGI was superior to filtration only; however, the polyester filter with UV lights (PFUV) was the most effective configuration. The PFUV effectively impeded the mould growth, with a 13.3% reduction in relative humidity and a 4.1 °C increase in the room temperature in the absence of a heating source. The results showed good potential for improving the IAQ of buildings. [ABSTRACT FROM AUTHOR]

In order to reduce the energy consumption of HVAC systems in buildings, the use of energy-saving solutions is necessary. One of these solutions is ventilation, which is usually used for maintaining acceptable indoor air quality and thermal comfort. As the change in outdoor environment is unpredictable and the occupant control is spontaneous, it is critical to control the windows and HVAC systems to achieve a maximum use of outdoor air for indoor ventilation. A new rule-based control strategy that could change the opening factor of windows is proposed in this study and its effectiveness was tested in five representative climates, ranging from a subtropical region to a severely cold region. A building model was set up and the indoor air temperature and energy consumption were predicted using EnergyPlus. The results show that the proposed control strategy can utilize ventilation to maintain a comfortable indoor environment with an annual uncomfortable percentage in an occupied period lower than 5%, thus leading to an energy-saving rate of 13.5–55.6%. The simulation results indicate that there are periods of ventilation available during the summer in climate zones with hot summers and warm winters, whereas the control strategy has a better energy-saving performance in temperate areas. This study conducted a preliminary exploration for practical applications of the combined operation of controllable natural ventilation and HVAC systems in buildings. [ABSTRACT FROM AUTHOR]

As most residents spend more than 90% of their time in buildings, acceptable and reasonable control of both indoor thermal comfort and air quality is imperative to ensure occupants' health status and work productivity. However, current control strategies generally take either thermal comfort or indoor air quality as a single loop, rather than the concurrent control of two. To analyze their mutual influence, this study investigated the performance of three multi-control approaches, i.e., proportional integral derivative (PID) control of thermal comfort and a fixed outdoor air ratio, PID control of thermal comfort and design outdoor air rate, and PID control of thermal comfort and occupancy-based demand-controlled ventilation. As a pilot study, three typical control methods were implemented to a multi-zone building via OpenModelica modeling. The results indicate that indoor air temperature can be well-maintained under three control methods, however, the CO2 concentration under the fixed outdoor air ratio was over 1000 ppm, leading to poor indoor air quality. The control strategy with the design outdoor air rate could not properly ensure the CO2 concentration, due to the over-ventilated or under-ventilated phenomena, subsequently resulting in unnecessary energy waste. The occupancy-based demand controlled ventilation could maintain the CO2 concentration under the set-point with an intermediate power energy utilization. [ABSTRACT FROM AUTHOR]