This field study was organized to determine the ventilation required to maintain acceptable air quality in a retail store using the ASHRAE Standard 62-1989 performance-based procedure. Pollutant concentrations and ventilation rates were measured in a large retail store during four one-week intervals. The measurement intervals were each separated by three months to allow different weather conditions and mixes of retail stock to be present over the one-year field study in a cold continental climate.
The development of guidelines for smart innovative mechanical ventilation systems is a task included in an ongoing research project partly supported by the European Commission in the framework of the Joule programme "TIPVENT - Towards Improved Performances of mechanical Ventilation systems". Before starting the actual work with the guidelines a survey was carried out to determine the level of current design methods for ventilation systems in the participating countries (Belgium, France, Great Britain, the Netherlands, Portugal, Sweden and Switzerland).
Ventilation is pivotal both in terms of indoor air quality and environmental issues such as greenhouse gas emissions. It also has a major impact on energy use in buildings. It is important, therefore that the role md impact of ventilation is filly understood. The purpose of this paper is to review these aspects with particular reference to recent research and developments. Key aspects are concerned with the role of ventilation in maintaining good indoor air quality, ensuring the quality of the outdoor air and incorporating strategies to ensure good ventilation performance.
The ventilation air intake (louver) is the first line of defence against an unfavourable outdoor climate. Unfortunately, the importance of this component is often an underestimated issue in the design process of many heating, ventilation and air conditioning (HVAC) systems. Field studies and inspections of a representative number of HVAC plants carried out between 1995 and 1998 in and around the city of Trondheim revealed that snow, and in several cases rain, easily passes through the air intake louver. Such intrusion of humidity can lead to unwanted microbial growth in the HVAC system.
In mechanical exhaust ventilated buildings in cold climates, the supply air through vents in the perimeter may cause draught and reduce the zone of occupancy. One way to prevent this is to preheat the outdoor air by a vent-convector. An experimental study of the performance of a vent-convector is reported in this paper. Measurements have been conducted in a test room and in a school equipped with vent-convectors. Air flow and pressure drop characteristics were investigated for one type of vent-convector. the temperature variation at a step change of the air flow was also investigated.
Suitable combinations of desiccant and evaporative cooling systems permit air processes alternative to the traditional ones for air conditioning applications. But owing to the high costs of desiccant wheels, we need very strong energy savings in order to demonstrate an economy validity. These savings can be possible today by the last generation of desiccant wheels where the most part of the regeneration heat can be supplied by heat recovery from chillers.
This field study was organised to track differential pressure relationships in critical care units of a metropolitan hospital. Maintaining design pressure balances is essential to control risk of airborne disease transmission within these units. the pressure differentials that exist between two patient isolation facilities (positive and negative) and their surrounding spaces were monitored continuously for one week.
The HVAC components are usually made of galvanised sheet metal which is covered by a corrosion protection and also lubricant oils are used in machine tools in manufacturing of the components or ducts. The aim of this study was to test and develop a consistent method to determine oil concentrations on component surfaces. Two swiping methods and a filter contact method were tested. In al of them the analysis based on IR-spectrometry. The results show that oil concentration is quite high and unequally distributed on the surface of the sheet metal containing corrosion protection oil.
Different ground-coupled earth-to -air heat exchangers have been constructed in many residential and occupational buildings in Switzerland to precool or preheat the incoming air. Many technical and energetic facts favour such systems. The objective of this study was to determine if microbial growth occurs within these tubes and if adverse health effects must be considered. The results show large reductions in viable bacteria and spore concentrations along the tubes and very low concentrations in the supply air compared to the outdoor air.