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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]

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]

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]

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]

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]

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]