measurements

There are several methods for measuring air tightness that may result in different values and sometimes quite different uncertainties. The two main approaches trade off bias and precision errors and thus result indifferent outcomes for accuracy and repeatability.  To interpret results from the two approaches, various questions need to be addressed, such as the need to measure the flow exponent, the need to make both pressurization and depressurization measurements and the role of wind in determining the accuracy and precision of the results.

Ventilation’s historical goal has been to ensure sufficient air change rates in buildings from a hygienic point of view. Regarding its potential impact on energy consumption, ventilation is being reconsidered today. An important challenge for low energy buildings lies in the need to master airflows through the building envelope. Data collected from controls in 1287 recent dwellings shows us that 68 % of the dwellings don't respect the French airing regulation.

Since 2000, the French EP-calculations have been considering thermal losses due to building envelope airtightness. The last two regulations (RT2000 and RT2005) had included a default value for airtightness and the possibility to use a better-than-default value with a mandatory justification of this value, especially for voluntary approaches such as the BBC-Effinergie label. In 2013, strengthening the airtightness has become a requirement of the current EP-regulation (RT2012).

The future is well-isolated buildings with low heating demand. The first office building in Norway satisfying the passive house standard, the GK environmental house in Oslo, was taken into use in August 2012.

For the coming energy-efficient buildings, the guarantee of energy performance becomes a major challenge. It is therefore crucial to implement accurate and reliable measurements, in order to ensure this performance. The in-force French EP-regulation RT2012 already imposes compulsory justification of envelope airtightness. Moreover, the Effinergie+ label requires ventilation systems control and ductwork airleakage performance. These requirements, ventilation controls for IAQ concern and regulatory compulsory controls of buildings need reliable diagnostic protocols.

A characterization and modeling process has been conducted in order to better account for ventilative cooling in the evaluation of energy performance of buildings. The proposed approach has been tested using a monitored zero energy Active House (Maison Air et lumière) located near Paris.

The purpose of this study is to figure out the characteristics of thermal environment in a workshop at school in Japan and to propose the improvement method of the thermal environment without air-conditioning systems. In this paper, measurement results of thermal environment in the workshop and calculation results of vertical temperature gradient are shown. In the measurement results, indoor air temperature became very high in summer. Solar radiation was the main factor raising the temperature of PC roof, and large vertical temperature gradient was formed.

Air tightness is an important property of building envelopes.  It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance.  Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ.  There are several methods for measuring air tightness that may result in different values and sometimes quite different uncertainties.

Most dwellings in the United States are ventilated primarily through leaks in the building shell (i.e., infiltration) rather than by whole-house mechanical ventilation systems. Consequently, quantification of envelope air-tightness is critical to determining how much energy is being lost through infiltration and how much infiltration is contributing toward ventilation requirements. Envelope air tightness and air leakage can be determined from fan pressurization measurements with a blower door. Tens of thousands of unique fan pressurization measurements have been made of U.S.

The Aluminerie Alouette Inc. (AAI) smelter in northern Quebec, Canada recently completed a major plant expansion that includes a new casthouse for the continuous production of low-profile, air-cooled aluminium sows. The radiation and convection heat release of 15 MW to the workplace from the aluminium metal solidification and cooling is significantly higher than that experienced in the traditional water-cooled casting process where the majority of the heat is removed by the cooling water.