air change rate

Decreased ventilation, achieved by weather stripping and other tightening measures, is the most cost effective way to energy conservation. A very low investment can result in a considerable decrease in ventilation rate. For a typical detached

The simple steady state model which is frequently used to relate radon concentration (C), source strength (S) and ventilation rate (l/tau) is expressed in the equation C=S tau. The assumptions of this model are given and their validity explor

Ventilation is widely used to help maintain acceptable indoor pollutant concentrations. In this paper, the relationships between ventilation rate and indoor concentration are examined by the use of mass balance models and measured data. It is shown that the pollutant source strength and pollutant removal by processes other than ventilation can have a large impact on the indoor concentration and that maintenance of a typical ventilation rate does not ensure an acceptable indoor concentration.

Air infiltration in two well-insulated houses is being investigated to determine its effect on energy use and indoor air quality. The first paper of this series provides a general perspective on the design. This paper reports on the effect on conservation measures taken, including the installation of an air-to-air heat exchanger, on air exchange and energy use. A third paper presents pollutant measurements and modelling results.

The paper proposes a methodology for evaluating and ranking specific alternatives for control of indoor air quality in existing buildings, based on comparative costs and benefits. The method avoids the difficulties of assigning a monetary value to a change in air quality by adjusting the air exchange rate in each alternative until equivalent indoor air quality is achieved. The difference in air exchange rates between alternatives allows calculation of energy savings, which can be compared to capital cost savings,which can be compared to capital cost using the payback period method.

As part of a comprehensive indoor air quality and infiltration field study, radon concentrations were measured in 60 houses in upstate New York using passive integrating monitors. Indoor air radon concentrations ranged from 0.2 pCi/1 to 50 pCi/1. Four houses with the highest radon levels were then extensively monitored using real-time continuous instruments for the measurement of radon, radon daughters, respirable particles, infiltration, inside-outside pressure difference, and weather parameters.

Plastic track detectors LR-115 and CR-39 were used to estimate the concentration of radon-222 and its daughter products (218Po, 214Po) in a room by recording tracks of their alpha-particles. Although the ventilation rate is the main factor th

The paper shows that age analysing techniques are an excellent tool to assess ventilation effectiveness. It is important to differentiate between air exchange effectiveness and contaminant removal effectiveness, having continuous generation of contaminants. Only when a source is homogeneous andpassive, are the age of the air and the contaminants in the room equal. However, the air exchange effectiveness accounts for the removal effectiveness of the contaminant left in the room when the generation stops.

Complaints related to moisture problems in houses which had been air sealed, led to a study of indoor air quality in 20 weatherized demonstration homes in the Cambridge, Ontario area. 

Discusses the effects of air infiltration and air change rate on temperature and humidity of indoor air. Attempts to quantify the relationship between surface temperature, thermal bridges, thermal resistance and indoor climate.