English

First the Subtask will organize a literature survey and make researcher contacts to gather relevant data and existing knowledge on major pollutant sources and loads in buildings, including models. Laboratory testing and model setup to provide examples of new types of data which shall be beneficial to improve knowledge on combined effects that must be taken into consideration in order to achieve new paradigms for energy optimal operation of buildings.

Subtask 1 of IEA EBC Annex 68 will aim at defining the metrics to enable a proper consideration of both energy and IAQ benefit in building design and operation

The overall objective of the IEA EBC Annex 68 is to provide scientific basis usable for optimal and practically applicable design and control strategies for high Indoor Air Quality (IAQ) in residential buildings. Naturally, those strategies should ensure minimal possible energy use. The project aims to gather existing and provide new data on pollution sources in buildings, model the indoor hydrothermal conditions and air quality as well as thermal systems, and will look to ways to optimize the provision of ventilation and air-conditioning.

In the frame of the European project called Bricker, a new prototype of single room ventilation with heat recovery has been developed. This new unit is supposed to be installed in class rooms of an educational institution. This paper deals with the development of the first prototype of this unit. An empirical model of such device is also proposed in order to be coupled with a building model. This aims at determining the seasonal performance of the device and thus the potential energy saving (compared to other technologies) resulting from its use.

The energy use in buildings is dependent on the choices made during the design, construction and renovation. The causes for these differences are, among others, caused by the behavior of the occupant of the building and the choice of heating and ventilation system. The European scheme of Energy Performance Certificates (EPCs) aims at reducing the energy use in the built environment. It is most common to calculate (i.e. not measure) the energy use for the buildings which are affected by the scheme.

Ventilation systems can save heat energy by using heat recovery, but consume electrical energy to power the fans. In practice, the energy efficiency of those systems can be lower than expected, when compared to the nominal values provided by the manufacturer. In this paper, results of a comprehensive field tests with 20 centralized and 60 decentralized ventilation systems for residential buildings and the calculation of the primary energy savings of those devices are presented.

Ventilation technologies are the key aspects to reach the target of nearly zero energy buildings. From 1st January 2016 on ventilation units have to comply with minimal energy efficiency criteria according EU Regulation No 1253/2014 of 7 July 2014 implementing Directive 2009/125/EC of the European Parliament and of the Council. Furthermore, residential ventilation units will have an energy label according EU Regulation No 1254/2014 of 11 July.

Conventional Displacement Ventilation (DV) system has been installed in an office of a Zero Energy Building (ZEB). Enhanced DV (EDV) system, consisting of fans mounted to the chair, which has been demonstrated in laboratory and field environmental chamber studies earlier was implemented for the first time in a full-scale office environment to assess its effectiveness of improving the thermal sensation of the occupants. Objective measurements and subjective assessments were conducted in the office with 12 occupants over a period of 2 weeks.

The paper presents a numerical methodology to assess the natural ventilation. UrbaWind is an automatic computational fluid dynamics code. It was developed to model the wind in urban environments. The turbulence modelling, namely the dependence of turbulence length on the distance from wall, and the model constants were calibrated in order to reproduce with good agreements flow separation around buildings walls and pressure coefficient field on façades. Numerical results match well with the experiments: separation patterns and pressure field on walls in dense urban areas.

As an alternative to adopting active architectural systems (mechanical systems) and taking advantage of the resources provided by nature, natural ventilation contributes interesting solutions to control the thermal balance and the air quality, and it is applicable in a variety of climate zones. Natural ventilation also solves some of the more common problems of mechanical systems, such as the noise factor and installation and maintenance costs.