A study has been undertaken to (1) evaluate airtightness in recent construction dwellings in New York State, (2) evaluate the effectiveness of various strategies in providing adequate ventilation, and (3) study the use of various ventilation options by residential builders and heating, ventilation and air-conditioning (HVAC) contractors.

Residential ventilation has at least two energy penalties that must be considered when addressing the ventilation levels recommended in ASHRAE Standard 62. Energy is required to heat the fresh outside air used for ventilation. In cold climates with high heating costs, an air-to-air heat exchanger can lessen the operating expense. Energy is needed for the fan motor used to introduce fresh outside air andlor to exhaust stale indoor air.

Workers in 'white collar' jobs continue to complain about air-quality' problems. Although there is a growing commercial interest in the measurement of gaseous and solid pollutants, there is no information on the effectiveness of New Zealand office ventilation systems. A set of baseline data is necessary to develop an understanding of the effectiveness with which air is provided in office spaces. This paper describes the results of preliminary ventilation effectiveness measurements made in mechanically ventilated spaces using a pulse tracer gas method.

Tracer-gas techniques are widely used for measurement of airflow in buildings and their accuracy depends critically on the uniformity of tracerlair mixing. However, tracer mixing is still an unsolved problem and the effect of many factors remains unclear. This paper presents a study of the effect on mixing of tracer species. The investigation concentrated on tracer mixing involved in the decay technique, which is the most widely used version of the tracer gas method.

As a result of the "Sick Building Syndrome" (SBS) the confidence of operators of office buildings into HVAC technologies has suffered a considerable drop. One of the most urgent questions before reconstructing or renovating old office buildings is, therefore, whether the air conditioning system to be installed will lead to increasing complaints on behalf of the occupants and how to prevent them. As for indoor air flows, one possibility is given by full scale model experiments leading to results which are very much like the future effective values.

This paper is concerned with measurement of air and aerosol particle exchange efficiency in a single zone chamber. Aerosol particles and tracer gases were injected into the chamber and their concentrations were monitored as a funtion of time. The chamber was provided with supply and exhaust terminals which allowed various airflow and particle patterns (e.g. piston flow, displacement flow) to be investigated. The effect of airflow pattern on deposition rate of aerosol particles on the surfaces of the chamber was determined.

Indoor air quality, comfort and energy use in buildings are largely dependent on the performance of HVAC systems. However, the pressure loss factors available to the designer show large discrepancies depending on the source of the data. In particular there are very few data regarding the effect on k-factors of interactions between duct components in close proximity. This paper describes measurement and computational fluid dynamics (CFD) modelling of pressure loss in HVAC system components. The results were compared with those data given in the ASHRAE and CIBSE guides.

The ventilation of a Swedish single family house is investigated by means of tracer gas and pressurization techniques. The ventilation flow plays an important role in this house as it enters through a dynamic loft insulation and exits via the crawl space. This design is said to give preheated and clean supply air, warm floors and good energy efficiency. But to meet these promises, it is essential that the air really flows in the intended paths. A single tracer gas technique is used to determine the air flow rates.

The idea that intend temperatures can be reduced by ventilating the air-space between the ceiling and the roof (the attic) of a house, is widely acknowledged by Civil Engineers and Architects. This phenomenon was evaluated through three softwares (CASAMO-CLIM, COMFIE and SPIEL) which were designed for the analysis of the thermal performance of buildings, by comparing the results of all three.

This paper presents a measurement technique to perform quantitative visualization of room air flows. The visualization is done by discrete particles, namely helium-filled soap bubbles, illuminated in a plane light sheet generated by a point light source in combination with a special lens. The recording is done stereoscopically with 3 standard cameras by streak photography. The scanned negatives are analysed digitally. The method is able to give the three-dimensional instantaneous velocity field of room air movements, also in real-scale.