Concentration of pollutants produced by car traffic in a street below the roof level has large spatial variations. In a street, pollutants are diluted by the turbulent air flow which is induced by the wind speed above the roof level, and also produced by car displacement. The airflow structure is in relation with street size and building shape. Particularly strong gradients of concentrations can be observed vertically and also horizontally in front and along buildings where are set up ventilation inlets and windows.

The principles of a new tracer gas technique is described in the paper. The new technique involves pulse injection of tracer gas and has the same advantages as the previously known homogeneous emission technique. It can for example advantageously be used in large buildings and buildings with many rooms and yields information on the distribution of ventilation air within the building. However, contrary to the homogeneous emission technique, yielding the average ventilation performance during an extended time, the new technique allows measurement during short term periods.

Pre-assessing the reliability of ventilation systems is a dificult task and no simple methodshave existed. This paper presents a tool for estimating the reliability of domestic ventilationsystems. In general, ventilation reliability means the probability that the chosen ventilationsystem performs in an acceptable way for a certain building, in a certain climate, betweenscheduled maintenance measures.

Contains the extra papers submitted to the above conference.

One basic goal of the commissioning process is to make sure that the HVA C system is functioning as intended. In particular, it is intended that the HVAC system not only provide adequate ventilation for the building occupants but also achieve adequate pressurization of the occupied spaces to prevent the infiltration of unconditioned air. One technique for evaluating the performance of the HVAC system in these areas is to use continual, multipoint monitoring of carbon dioxide, carbon monoxide, and dew point at selected locations in the building and the HVAC system.

To remedy comfort problems in a 99,000 fi2 (9,200 m2) office building, the total airflow rate was reduced by 35%, and the total outside airflow was reduced by 86% in four multi-zone air-handling units that serve the office building. After the airflow reduction, the peak room relative humidity level was reduced from 70% to 55%, and cold and hot deck reset schedules were implemented. These improved operating practices reduced building energy consumption by 27%.

This paper discusses the development and application of standards of performance (SOPs) for HVAC&R equipment, plumbing systems, and building envelope systems in relation to maintaining acceptable indoor air quality (IAQ) in buildings. The utilization of the SOP procedure, developed in ASHRAE Research Project 853, will aid in the proper operation of systems and verify that acceptable building IAQ levels are obtained.

This research evaluated the performance of four kinds of ventilation systems for dwellings under various conditions by means of numerical simulation. The total number of combinations of various parameters for the calculation was 174. Calculations were performed hourly for indoor air pollutant concentration, humidity and condensation, indoor outdoor pressure difference, airflow rate, and heat energy by ventilation, etc., through the heating season. A multizone infiltration and pollutant transport model (COMIS) was used to perform the simulation.

Residential air infiltration rates predicted by a detailed multizone computational model are compared with those predicted by a single-zone model. The multizone model is created using the public domain program CONTAM96, which allows the user to break the house into a number of Zones connected to one another and the outdoors by leakage paths with user-defined characteristics. Actual floor plans for a ranch-style house and typical published leakage characteristics of residential building components are used to construct a very detailed model with roughly 2,000 zones and 7,000 leakage paths.

Forced air distribution systems in residential buildings are often located outside conditioned space, for example in attics, crawlspaces, garages and basements. Leaks from the ducts to these unconditioned spaces or outside can change flows through the registers and change the ventilation rates of the conditioned spaces. In this study, duct leakage flows were measured in several low-rise apartment buildings. The leakage flow measurements and other data about the apartments were used to develop a prototype apartment building.