building

Indoor air pollution is a significant concern due to its adverse effects on human health and productivity. With people spending most of their time indoors, exposure to indoor air contaminants can lead to various health issues, including respiratory problems, cardiovascular diseases, and even an increased risk of lung cancer and premature mortality. Additionally, poor indoor air quality can result in short-term symptoms like headaches, eye and throat irritation, fatigue, and asthma, impacting workplace productivity and absenteeism.

This paper summarizes the most recent results of the French database of ductwork airtightness. This database was created in 2016. It is fed through measurements performed by qualified testers according to a national scheme regarding ductwork. Measurements are mainly performed in building applying for the Effinergie + label which requires class A for ductwork airtightness. Therefore, results discuss in this paper only apply to the buildings of the database and cannot be generalized to all new buildings in France.

This paper analyses the contribution of a steady wind to the uncertainties in building pressurisation tests, using the approach developed in another paper (Carrié and Leprince, 2016). The uncertainty due to wind is compared to the uncertainties due to other sources of uncertainty (bias, precision and deviation of flow exponent).
The main results of this study are:

In France, the current regulation on the energy performance of buildings (RT 2012) does not require ductwork airtightness measurement when the default-value is used in the regulatory EP-calculation. Thus, measurements are only mandated when a specific airtightness level is used in EP-calculations or required by a voluntary certification scheme. In such case, measurements have to be performed according to a national scheme regarding ductwork airtightness measurement.

Today one out of six Europeans (84 million Europeans, or the equivalent of Germany’s population), report deficiencies regarding the building status. In some countries, that number is as high as one out of three. This puts these buildings in the ‘Unhealthy Buildings’ category, which is defined as buildings that have damp (leaking roof or damp floor, walls or foundation), a lack of daylight, inadequate heating during the winter or overheating problems.

The characterization of power-law coefficients of the airflow through ventilation system components and ductwork or building leaks should include corrections on the airflow rate measurement because of two phenomena: a) the temperature and pressure conditions at the flow measurement device may not be the same as those seen by the test object; b) the temperature and pressure conditions experienced by the object may differ from reference conditions. This paper gives the analytical expression of these corrections depending on the air viscosity, air density and flow exponent.

This paper presents the development of a computer model of an academic building using the EnergyPlus program and its calibration with monitored data. The new Concordia Sciences Building (CSB), located in Montreal, has a total floor area of 32,000 m2. The size and the complexity of the heating, ventilation and air conditioning (HVAC) and heat recovery systems make the modeling process a challenge and an excellent opportunity to evaluate the capabilities and features of EnergyPlus in this particular context.

A mathematical model for simulating airflow in solar channel of the insulated Trombe solar wall system is proposed. It is assumed the glazing is isothermal and the solar heat absorbed by the wall is transferred to  the air in the channel with a constant flux by natural convection. The mass, momentum and energy  conservation equations are discretized and solved using the finite difference control volume method. An experimental study of solar chimney was used to validate the proposed mathematical model.

French standard for airtightness measurements is NF EN 13829. It is completed by French application guide GA P50-784, to set calibration rules more precisely, among other issues. This guide was published in 2010. To answer measurers’ remaining questions, a Frequently Asked Questions web site was created by CETE de Lyon.

Tracer gas measurements are an unparalleled means of measuring air recirculation, leakage, and air flow rates in air handling systems [1-5]. However, such measurements are subject to significant measurement uncertainty in field conditions. A common problem is imperfect mixing of tracer gas.