This report describes a technique which models the infiltration process for an entire enclosure more accurately than standard methods. Both air flow and convective/conductive heat transfer are accounted for to (a) improve building heat load calculations, (b) determine the important characteristics of existing (and new) buildings for infiltration heat loads, and (c) account more accurately for wind effects.
Reviews ways of reducing energy loss due to infiltration while maintaining air quality. Results from existing houses are presented. Describes a method to reduce the average air flow coefficients of the envelope to minimum required values and to determine the heat criteria of various ventilation systems.
Over the last few years frequent cases of mould growth in dwellings have occurred. The problem is essentially due to an excessive moisture content of the building elements, which can result from hygroscopic adsorption or from frequent surface condensation.
The interpretation of the data presented in the named article (by Nazaroff W W et al, NO 1767) is extended to develop an improved model that can be used to predict radon concentrations in the single family house tested and possibly inothers as well. In particular, a more complete set of low sump activity data has been replotted.
Modelling houses as two coupled chambers, namely, the living area and basement, predicts more accurately the total indoor radon source flux from building materials and geology than a one-chamber model in houses with disparate radon concentration
Outlines the foundations for calculating and designing natural ventilation: conditions for the building unit: technological prerequisites: components: sound insulation: calculation methods: fields of application: combination of mechanical and natural ventilation: and models for optimization of new buildings and for reconstructing factories.
Simulation of the thermal performance of a building to take account of uncontrolled infiltration shows that infiltrating air on a leakage path is efficiently warmed up, especially if infiltration flow rates are low. For allowable infiltration flow rates with respect to thermal comfort, (0.5 -0.7 dm3/sm), the heating is 25 - 60 per cent of the temperature difference between the outside and inside air. For the longest leakage path, the incoming air is even near to the room air temperature.
The heat losses from small houses, due to transmission and ventilation, are estimated. The estimation i s based up on the house owness daily readings of electricity and water meters, and their notes on behaviour influencing the energy use. Consideration is taken to heat supply from insolation and from people. Hot water losses are calculated from use of water and use of household machinery. Besides the estimation of the heat losses, Q, wind and temperature in the area is registrated .
The normally used equation for calculation of infiltration flow rates into a house is a power law of which the exponent n is normally assumed to be 0.66 but sometimes values of 0.5 or even 1 can be seen in the literature. In this paper the constant n is calculated assuming a non fully developed infiltration flow. The constant n will for this assumption take values between 0.67 and 0.77 if the slots where the flow takes place are long enough to get a flow close to a developed one.
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