Airtightness of French dwellings: results from field measurement studies.

A field measurement study of the airtightness of 73 - less than 5 year old - French dwellingswas led between 1999 and 2000. Buildings have been selected and classified according to theconstruction structure, the thermal insulation and the occupancy mode. Using a fandepressurizationtechnique, we assessed the air leakage rate of each dwelling with twodepressurization tests. Meanwhile quantifying air leakage rates, we observed qualitatively themost frequent locations of air leakage paths using a smoke detection method and infraredthermography.

Design pressure difference for self adjusting air inlets.

At present the design pressure difference for air inlets in The Netherlands is 1 Pascal. This paperinvestigates the question whether or not this value is still appropriate.In recent years the airtightness of dwellings has improved remarkably. Self adjusting air inletshave been introduced on the market. What is the effect of these changing building features onthe pressure difference over the building envelope?

Controlled double facade for preheating ventilation.

In the recent past new concepts for the building envelope have been developed with theunderlying wish to improve the energy performance of a building as well as comfortconditions in the inner spaces. Examples are: solar walls, high-tech window systems, doublefacades and integration of daylighting systems and of PV-panels. In this paper the doublefacade concept is discussed.This kind of facade is considered as a device to be used for pre-heating the ventilation airduring winter as well as for nocturnal cooling of the building during summer.

Air flow and thermal analysis of a forced air heating and ventilation system.

The prediction of energy use, air flows and temperatures in different rooms of a building andat different climatic conditions is very important, especially when evaluating new conceptsfor heating and ventilation systems in combination with different building envelopeconstructions. A thorough system analysis considering coupled air flow and thermalcalculations becomes very complex if e.g. thermal bridges and dynamic conditions areconsidered.

How do winds affect buoyancy-driven ventilation in buildings?

This paper examines theoretically the effects of wind on buoyancy-driven ventilation via some new analytical solutions recently developed by the authors. Three air change rate parameters are introduced to characterise respectively the effects of thermal buoyancy, the envelope heat loss and the wind force. The wind can either assist or oppose the airflow. For the first time, it has been found that for opposing winds, there are two stable ventilation flow rates for a given set of wind and thermal parameter, i.e. the natural ventilation flow exhibits hysteresis.

Building envelope and conditioning unit interaction: a case study.

The building may be seen as a "container" of a conditioned environment where man comfortably carries out a number of activities. The achievement of acceptable indoor environmental conditions depends on the way such a container is realized. In other words, the whole building, which is designed to create a space in which man can suitably carry out certain activities, contributes with all its parts to controlling the desired environmental conditions.

The application of dynamic insulation in buildings.

                   

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