This article compares the requirements for mechanical ventilation systems in the new German regulation on energy savings (EnEV 2002) with those contained in the previous regulation (named WSchV 1995). It also gives information about the way to test and certify mechanical ventilation components according to this new regulation.
The aim of ventilation for commercial kitchens is capturing fumes and odours, providing fire protection measures and insuring comfort. But the technologies concerning extraction and introduction of fresh air are not numerous.In this article, the author explains how difficult are the dimensioning of the equipment and the calculation of the airflow to extract.The author also refers to guide and regulations related to commercial kitchens.
This study concerns single-sided natural ventilation by using a CFD model, along with analytical and empirical models. The effects of opposing buoyancy and wind forces on ventilation rates and indoor conditions were alos studied in that investigation.
Ventilation systems designed for a constant air volume (CAV) provide fresh air in office buildings. It means that very often huge amounts of energy can be wasted on ventilating empty offices. A simple analysis of the profitability of Demand Controlled Ventilation (DCV) has been performed on a reference office building in Norway.
The aim of that study was to develop a fuzzy controller for naturally ventilated buildings. This paper describes the process of designing a supervisory control to provide thermal comfort and adequate air distribution inside a single-sided naturally ventilated test room.
Maintenance of air-conditioning systems is acknowledged as an important means to run HVAC-systems properly. Although several maintenance programs and standards exist, not many systems are maintained in a proper way. Most standards and programs are not concerned with the indoor environment, they are only concerned with repair and failure-response of system components. Just now, some new guidelines come out in Europe, which contains first definition of cleanliness.
The development of indoor air quality was studied in three newly finished buildings in Helsinki, Finland during the years 2000-2002. The concentration of volatile organic compounds (VOC), formaldehyde and ammonia, for which the Finnish Classification of Indoor Climate 2000 gives target values, in indoor air as well as the air exchange rate, relative humidity and temperature were determined for the newly finished buildings and 6- 12 months after the buildings had been taken in use.
Thermal comfort variables were measured in Singapore mechanically ventilated classrooms. In parallel the cccupants filled questionnaires on their perception of the indoor climate. The results showed that ASHRAE Standard 55 was not applicable in free-running buildings in the tropics. The study showed that generally cool thermal sensations were more readily accepted by the classroom occupants than warm thermal sensations.
This article discusses how to integrate all air-to-air devices into an HVAC system that may contain one or more air-to-air exchangers as well as conventional components for ventilation and comfort control.HVAC systems with air-to-air exchangers need to be carefully designed for the location of each device in the system, with the winter and summer design performance of each device and the total annual energy saved by the HVAC system.
Variable Air Volume system use VAV boxes that serve open areas for five or more occupants, each zone is controlled with a single space temperature sensor. But VAV zone control strategies remained the same for the last years, so the designers have to consider that system : it provides a high quality environment for occupants, it permits the use of a smaller air-distribution system that is low cost and does not compromise building comfort or operating efficiency.