The steepest descent and simulated annealing optimization techniques are used to simultaneously estimate the effective mixing volumes and air exchange rates of a large partition less building exhibiting heterogeneous spatial air flow conditions. The optimization is conducted using varying quantities and qualities of simulated tracer gas measurements. A simulated three-compartment system is numerically investigated to assess the performance of the parameter estimation methods.

Constant injection of tracer gas was used to determine the airtightness of a straight length of300 X 300 mm square duct in a laboratory setting. Holes are performed in the ductwork which is connected to a fan with variable speed control to simulate leakages. The holes can be sealed with rubber bungs to simulate an airtight ductwork. 'Stationary' and 'mobile' methods have been developed. The stationary method is suitable for conditions where the locations of the leaks in the ductwork is known.

Particle loss augmentation in turbulent flow was studied experimentally. Experiments were performed in a I SO mm square ventilation duct. Small tracer particles of size ranging from 0.7-7.l μ.m were used to study deposition enhancement with streamwise-periodic disturbances mounted on one of the principal walls, under turbulent flow. A new and highly sensitive analytical technique was adopted to determine the spatial mass flux along the ribbed duct. On some surfaces, particle deposition enhancement as much as seven times higher than on .smooth surfaces was observed.

The purpose of this study was to correlate building envelope performance problems which are currently being experienced in low rise wood frame residential buildings in the coastal climate of the BC Lower Mainland, with sources of moisture, and design and construction features. This study has facilitated the identification of key aspects of the design, construction, operations and maintenance processes leading to the problems, which in tum provides the construction industry with focal points for the development of solutions to the current problems.

A pressure-equalized rainscreen (PER) wall is a multiple-line-of-defence approach to rain penetration control. This Update defines pressure equalization and discusses the various elements that must be incorporated in a PER wall to minimize rain penetration due to air pressure differentials.

An experimental setup is presented that can measure concentrations generated around a pulsating source of carbon dioxide (C02) that simulates human respiration. The experimental setup is used to study the relationship between the ventilation efficiency and the pollutant removal efficiency of a space. These are two key parameters which describe the ability of a space in providing a comfortable and healthy environment for its occupants. Preliminary results obtained so far have focused on the conditions inside a small test chamber.

This report is based on a pilot project for a large epidemiologic study of inner-city asthma, in which exposures to air pollutants will be related to both incidence and prevalance of asthma. Nitrogen dioxide concenmuions were measured in three rooms as well as outdoors in 44 inner-city apartments with gas cooking stoves. Fifty-two separate month-long series of 48-h time-integrated NO, sample. (Palmes tubes) were gathered from fall 1982 to spring 1984. The 48-h average N02 concentrations taken within homes frequently exceeded the U.S.

A total of 20 toxic, carcinogenic, or mutagenic organic compounds were measured in the air and drinking water of 355 residents of Bayonne and Elizabeth. New Jersey, in the fall of 1981. The participants were selected from over 10,000 residents screened by a probability sampling technique to represent 128,000 persons (over the age of seven) who live in the two neighboring cities. Over one hμndred geographic areas throughout the two Cities were selected for monitoring. Each participant carried a personal sampler with him during his normal daily activities for two consecutive 12-h periods.