English

This paper presents the results of a series of 30 fan pressurization tests in reproducibility conditions performed within a period of 10 days in October 2017. The tested unit is a newly constructed unoccupied apartment in Brussels. These results make possible to compare different regression methods and evaluate the impact of pressure stations chosen for these regressions.

The air infiltration of a building, which fundamentally depends on its airtightness, can be a significant contributor to its heat loss.  It can also be affected by other factors such as external terrain, leakage distribution, sheltering factor and environmental conditions. The infiltration rate of a detached UK house was monitored for 2 months in early 2018 using constant concentration and decay tracer gas methods under various temperature and wind conditions.

This paper introduces an experimental study of enclosure airtightness testing of an outdoor chamber using both the pulse technique and the blower door method.  This investigation is a 2nd stage comparison study following the previous testing of a house-sized chamber in a sheltered environment.  The outdoor chamber in this study has dimensions, approximately half that of a standard 20ft long shipping container.  Multiple openings were installed into the chamber’s envelope to provide a leakage level and characteristics similar to an average UK house.

Since the 1970s, many authors have discussed the impact of poor airtightness on building energy use, indoor air quality, building damage, or noise transmission (Carrié and Rosenthal, 2008) (Tamura, 1975) (Sherman and Chan, 2006) (Orr and Figley, 1980). Nowadays, because poor airtightness affects significantly the energy performance of buildings, and even more significantly with low-energy targets, many countries include requirements for building airtightness in their national regulations or energy-efficiency programs.

From September 2015 to March 2016, UTC engaged in a major refurbishment of its Design and Research Center located in Culoz (France).

In-situ performance of mechanical humidity-based mechanical exhaust ventilation (RH-MEV) is characterized in this study. This ventilation system includes fully-mechanical air inlets in the dry rooms and exhaust units in the wet rooms: the extensions and retractions of a hygroscopic fabric modify their cross-sections upon hygrometric changes in their environment without the need for motors or electronic sensors. 

With 35 years of existence and more than 10 million equipped dwellings, mechanical humidity-based demand-controlled ventilation (RH-DCV) can provide a comprehensive feedback on installation, aging, and maintenance of its components. Their working principle is based on the extensions and retractions of a hygroscopic fabric, which pulls on a shutter to modify the device’s cross-section – hence the airflow – upon humidity changes in their environment. 

The communication presents the Technical Appraisal Procedure followed in France for Demand-Controlled ventilation systems through the illustration of the use of a thermo-hygro-aeraulic nodal model called MATHIS developed by CSTB. The calculations methodology is described. Its application is illustrated for different family of ventilation systems currently under the scope of the procedure. The needs and the current developments for a better modelling of Indoor Air quality are lastly exposed. 

Demand controlled ventilation systems are representing a large majority of installations in France. They are commonly used for more than 35 years. The strong development of these systems can be explained by the French regulatory framework for air renewal. These demand controlled systems have been developed in order to optimise the energy consumption and at the same time to ensure indoor air quality and building durability. In residential buildings, demand control is based mainly on humidity whereas in commercial buildings it is based on occupancy and/or CO2 levels.

Recent studies have shown that ventilative cooling reduces overheating, improves summer comfort and decreases cooling loads. Therefore, it is considered as one of the most efficient way to improve summer comfort. Although, HVAC designers still lack of guidelines to improve the energy and comfort efficiency of their installations.