English

The current development in building energy efficiency towards nearly-zero energy buildings represents a number of new challenges to building design and construction. One of the major challenges is the increased need for cooling present in these highly insulated and airtight buildings, which is not only present in the summer period but also in the shoulder seasons and in offices even during occupied hours in winter. In most post-occupancy studies of high performance buildings in European countries elevated temperature levels is the most reported problem, especially in residences.

With the trend towards low-energy buildings, the importance and the interest for building air tightness is increasing. This implies an increasing number of tests, calling for increased attention to the quality of those tests including the way the test results are used to justify for programme or regulatory requirements. In turn, those tests put pressure on builders and craftsmen to reliably attain good airtightness levels. The project will review existing approaches and will analyse their pros and cons.

There is no doubt that, as part of this tendency to move to nearly zero energy buildings, in most climates buildings have to become more airtight. Should there be specific airtightness requirements? If so, what level is to be required? Should there be a minimum level of air leakage? This is the context for this project regarding the ‘philosophy about airtightness requirements’.

There are several national initiatives to collect air leakage data from field measurements buildings as a whole, building components, or ductwork systems. However, at this stage, there is no structured communication between these actions although they could mutually benefit from sharing their experience and encourage other similar initiatives in other countries having in mind the lessons learnt from the previous ones.

The European standard EN 15251 specifies design criteria for dimensioning of building systems. In detail, it proposes that the adaptive comfort model is used, at first, for dimensioning passive means; but, if indoor operative temperature does not meet the chosen long-term adaptive comfort criterion in the “cooling season”, the design would include a mechanical cooling system. In this case, the reference design criteria are provided accordingly the Fanger comfort model.

Many simulation software to predict thermal environment of buildings, such as temperature, humidity, heating and cooling load of building spaces, have been developed. However, most of them do not take into account moisture transfer in wall assemblies. Then, sensory index such as standard new effective temperature is even excluded from calculation. A Heat, Air and Moisture (HAM) simulation software called THERB for HAM has been developed for the purpose of estimating the hygrothermal environment within buildings.

This paper presents a library of simplified, yet accurate, physical models of the different components that can be found in a typical air-handling unit. Models development was focused on high accuracy with low computational cost aiming at the use of the library for real time applications like fault detection and diagnosis. Model library was developed to reduce to the minimum the initial data needed for setting up a simulation model. The data needed is commonly found in the datasheets provided by the manufacturer.

Along with the outdoor climate, building design, materials and construction system determine the thermal behaviour of buildings, the ability to keep indoor comfort conditions and the energy consumption through their lifespan. Buildings must provide comfortable indoor environment which should be reasonably assured regardless of climatic fluctuations. This paper presents a novel methodology for quantifying the hygrothermal discomfort risk of any building design.

In France, non-residential buildings account for a sig-nificant part in energy consumption. Moreover, a large part of this consumption is due to Heating, Ventila-tion and Air-Conditioning (HVAC) systems, which are generally badly handled. So, the present work deals with an efficient approach allowing energy consump-tion to be minimized while ensuring thermal comfort. In this sense, a predictive control strategy is proposed for existing zoned HVAC systems considering the Pre-dicted Mean Vote (PMV) index as a thermal comfort indicator.