PREFACE INTRODUCTION OUTDOOR AND INDOOR CONDITIONS Overview Outdoor Conditions Dry bulb (or air) temperature Solar radiation Long wave radiation Relative humidity and (partial water) vapour pressure Wind Precipitation and wind-driven rain Standardized outside climate values Indoor conditions Dry bulb (or air) temperature Relative humidity and (partial water) vapour pressure Water vapour release indoors Indoor climate classes Indoor/outdoor air pressure differentials PERFORMANCE METRICS AND ARRAYS Definitions Functional demands Performance requirements Some history Performance arrays FUNCTIONAL REQUIREMENTS AND PERFORMANCES AT THE BUILDING LEVEL Thermal comfort Health and indoor environmental quality Energy efficiency Durability Life cycle costs Sustainability HEAT-AIR-MOISTURE PERFORMANCES AT THE ENVELOPE LEVEL Introduction Air-tightness Thermal transmittance (U) Transient thermal response Moisture tolerance Thermal bridges Contact coefficients Hygrothermal stress and strain Example of performance control: timber-framed walls HEAT-AIR-MOISTURE MATERIAL PROPERTIES Introduction Dry air and water Building and insulation materials APPENDIX

In metal roofs, interstitial condensation is one of the main malfunctions. Metal sheeting in fact has a thermal resistance close to zero and cannot buffer moisture. As a consequence, condensation typically results in water droplet accumulation and dripping. Since decades, the industry proposes two rules of practice to prevent the problem: a vapor barrier below and a ventilated air space above the thermal insulation. A performance based analysis shows that both measures may function most inadequately if acceptable air-tightness is not guaranteed and condensation by clear sky radiant cooling is not neutralized. The research advances some new priorities in metal roof design: air-tightness, non-vented compact solutions and the use of a sorption active support below the sheeting.

The term ‘museums’ relates to a broad range of buildings with one objective in common: storing, preserving and showing collections of artefacts, ranging from locomotives and cars over furniture to parchments, old books, paintings and other delicate pieces of art.

The word 'moisture' relates to water in its three states that is vapour, liquid and solid with inclusion of all substances, such as salts, dissolved in it. Moisture is responsible for 70 to 80% of all damage in buildings. Thus, correct moisture control is a prerequisite for getting sustainable buildings. Several driving forces cause moisture to move in and through open-porous materials. Looking to the vapour phase, two intervene: diffusion and bulk transport. Moisture modelling is never an activity on its own. As temperature and air pressure differences act as driving forces, one always has to combine with heat and air transport, the whole being called hygrothermal modelling. Solving a combined heat, air and moisture problem demands knowledge of the exact geometry of a building assembly, together with the starting conditions, the exterior and interior boundary conditions and the contact conditions between material layers.

Since the 1990s, the successive EU directives and related national or regional legislations require new construction and retrofits to be as much as possible energy-efficient. Several measures that should stepwise minimize the primary energy use for heating and cooling have become mandated as requirement. However, in reality, related predicted savings are not seen in practice. Two effects are responsible for that. The first one refers to dweller habits, which are more energy-conserving than the calculation tools presume. In fact, while in non-energy-efficient ones, habits on average result in up to a 50% lower end energy use for heating than predicted. That percentage drops to zero or it even turns negative in extremely energy-efficient residences. The second effect refers to problems with low-voltage distribution grids not designed to transport the peaks in electricity whensunny in summer. Through that, a part of converters has to be uncoupled now and then, which means less renewable electricity. This is illustrated by examples that in theory should be net-zero buildings due to the measures applied and the presence of enough photovoltaic cells (PV) on each roof. We can conclude that mandating extreme energy efficiency far beyond the present total optimum value for residential buildings looks questionable as a policy. However, despite that, governments and administrations still seem to require even more extreme measurements regarding energy efficiency.

Trials to model combined heat, air, moisture transfer in and through building assemblies started in the 1930-ties, when the first methodologies surfaced that coupled steady state vapour diffusion to steady state heat transport. Thanks to H. Glaser and his papers published end of the 1950-ties, that diffusion/conduction approach gained physical correctness. Some 13 years later, capillary suction was added as transport mechanism. At that time, computer software already helped solving models that linked transient heat transport to moisture transfer by diffusion and suction in composite assemblies. Later, air got included as carrier for heat and vapour while increased computer power allowed analyzing two- and three-dimensional geometries. After 2000, the turn from the assembly to the whole building level gained attention.Although the theory looks well established and the computer software, actually available, quite complete, still it does not always help explaining and curing the damage cases, encountered in practice. As built complicates things and physics related pitfalls remain: simulations base on too simple drawings, inability to correctly include airflow, overlooking pressure and gravity driven water flow, uncertainty in material properties, difficulties to grasp the real initial and boundary conditions, the complexity of the envelope/building interactions, etc. (C) 2015 Elsevier Ltd. All rights reserved.

Buildings need to be energy efficient. Nobody doubts that. However, when it becomes the sole paradigm, unwanted consequences may be the result.In this paper, the case of a passive house is discussed; this house was declared uninhabitable less than two years after the inhabitants, a family of five, moved in. The enclosure consisted of a timber-framed facade finished with a brick veneer and a pitched tiled roof, both with U-factor 0.13 W/(m(2).K)/0.023 (Btu/[ft(2).h.degrees F]), argon-filled, low-e (layer with low long wave emissivity covering the cavity looking glass surfaces in double or triple glazing) triple glazed timber windows with average U-factor 0.74 W/(m(2).K) (0.13 Btu/[ft(2).h.degrees F]) and a floor-on-grade, annual mean U-factor 0.16 W/(m(2).K) (0.028 Btu/[ft(2).h.degrees F]). A balanced ventilation system with heat recovery supplied the fresh air, while a heating coil in the supply duct after the recovery unit cared for heating. Supply air first passed through a ground tube before entering the recovery unit. Airtightness should have been such that n(50) did not pass 0.6 h(-1).Soon after moving in, the inhabitants complained about degrading health. On-site measurements showed the indoor air was quite polluted, while relative humidity was remarkably high. A closer look revealed stagnant water in the ground tube, a too-low fresh air supply, an inadequate design of the ventilation, heating, and domestic hot-water system, and an oriented strand board (OSB) air barrier inside the enclosure that turned quite humid at the rain-side during summer and acted as effective UF-source that way.

This chapter contains sections titled: In general Glass Windows and doors Glass façades References and literature

In this paper, the feasibility of passive cooling in newly built office buildings in the temperate climate of Belgium is assessed using the standardized adaptive comfort criteria. This is done through Monte Carlo uncertainty analysis of the simulated weighted exceeding time for different building designs with varying insulation level, glazing-to-wall-ratio, glazing type and air tightness. Two passive cooling schemes are studied: diurnal manual window operation and the combination of diurnal manual window operation and passive night ventilation. Additionally, two possible measures to limit heat gains, external solar shading and daylighting, are considered.The integration of a detailed model of window operation, establishing a real-time coupling between the thermal model and the behavioural model and thus allowing simulating adaptive behaviour, is shown to impact the results significantly and is therefore recommended by the authors.The uncertainty analysis shows that it is possible to cool office buildings solely by diurnal manual window operation, even for highly insulated and air tight buildings. This requires minimizing heat gains to about 900 kJ/m(2) per working day during summer months. When a combination of diurnal window operation and night ventilation is available, limiting the heat gains to about 1500 kJ/m2 per working day suffices. (C) 2012 Elsevier Ltd. All rights reserved.

This chapter contains sections titled: In general Performance evaluation Design and execution References and literature

This chapter contains sections titled: Traditional masonry walls Massive light-weight walls Massive walls with inside insulation Massive walls with outside insulation References and literature