Air change rates were measured in one two-storey detached house with five basic types of passive ventilation systems: an intake vent in the basement wall, an outdoor air supply ducted to the existing forced air heating system, an exhaust stack extending from the basement to the roof, and two combinations of the supply systems and the exhaust stack. An expression was developed for estimating house air change rate from house airtightness, neutral pressure level and indoor-outdoor air temperature difference.
Studies the direct coupling of ventilation heat and solar gains to increase the performance of passive solar systems. Examples of particularly suitable buildings are described. The thermal model FRED, based on a thermal resistance network representing a three-zone building, is modified to include a simple airflow model driven by wind speed and temperature difference. The simulated building is ascribed symmetric permeabilities, then asymmetric permeabilities.
The R-values of permeable insulation systems are generally determined in test apparatus designed to assure one-dimensional heat transfer and to assure no air intrusion effects. Such classical R-values are used to help describe insitu heat-tra
Makes an experimental investigation of the distribution of pressure differences across the walls of a 20-storey student residence building at the University of Ottawa. Measures the wind velocity at the test building as well as the temperature distributions both inside and outside the building.
Treats the three main factors contributing to ventilation heat loss- natural air exchange driven by wind pressure and temperature differences, air exchange caused by the user and forced air change under the influence of exhaust air installati
Presents an analytical procedure for evaluating the air change rate in a room due to the temperature difference between the interior and exterior, which occurs when a door or window is opened.
Reports measurements of air infiltration and air leakage of an unpartitioned mobile home, made in an environmental chamber. Infiltration was measured using sulphur hexafluoride as a tracer gas. Leakage was measured by depressurizing the mobile home. Discusses results and uncertainties in the air change rates. Examines dependence of air change on indoor-outdoor temperature difference. Compares results with previously published measurements and discusses anomalies.
Reports an investigation of the effects of temperature differences, pressures, sun and wind conditions on a thermal image produced by thermography. This investigation is concerned mainly with measurement points associated with air leakage. Reports measurements on a single-storey timber-framed house under a pressure difference of 5,-2,-10 and -20 Pa.
Considers the characteristics of flow through small gaps. Discusses relation between wind tunnel measurements and actual wind pressure on buildings and the effect of building shape on ventilation. Derives equations for flow rate through a gap for different temperature and pressure differences and sizes of gap. The equations consider the pressure as a function of time thus modelling the effects of a turbulent wind incident on a gap.
Gives theoretical calculation of the amount of air which moves from one room to another due to a temperature difference between the two rooms. Suggests the possibility of reducing the heating or cooling load by allowing an overpressure in one of the two rooms.
Login