PR2017

The Proceedings of the 38th AIVC Conference "Ventilating healthy low-energy buildings", held in Nottingham, UK, 13-14 September 2017.

The Presentations at the 38th AIVC Conference "Ventilating healthy low-energy buildings", held in Nottingham, UK, 13-14 September 2017.

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:

This paper discusses two particular points of the buildings airtightness measurement method (ISO 9972) in relation with the calculation of the combined standard uncertainty: (1) the zero-flow pressure difference and (2) the weighted line of organic correlation.

Based on 3 short time performance measurements, 4 visits together with user-interviews, 3 involvements in Ventilative Cooling (VC)-building-design, 2 long-term case studies and 11 expert interviews the paper presents a list of key performance-indicators of successful Ventilative-Cooling solutions as well as challenges together with examples of their successful overcoming.

Information has been collected from projects located in Austria, using Ventilative Cooling, both natural and mechanical ventilation, in both residential and office buildings, mainly in urban surroundings.

The importance of reducing the ingress of outdoor pollution into the indoor environment is becoming increasingly important as concerns rise regarding the acute and chronic health effects of air pollution. In general, people in developed countries spend typically 90% or more of their time indoors, with the most susceptible individuals, such as the elderly and those with pre-existing medical conditions, spending almost all of their time indoors.

Experiments are presented on turbulent buoyant free-line and wall plumes, whereby the buoyancy source is emitted from a horizontal line source, in one case free of the presence of a wall and in the other placed immediately adjacent to a wall. The dynamics of turbulent entrainment, whereby ambient fluid is mixed in to the plume, are explored. The velocity field and scalar edge of the plumes are measured. From this the time-averaged plume-width and volume flux are compared.

We present preliminary results from an examination of the capture and venting of a buoyant plume by a chimney. The aim is to enable improved management of indoor pollutant sources – for instance, the plume rising from a cooking pan in a kitchen or a cooking fire in a hut. Using the principle of dynamic similarity, we precisely and controllably model the behaviour of indoor plumes by using saline solutions ejected into an enclosure containing freshwater.

Indoor air quality and thermal comfort was measured in 14 three-bedroom, semi-detached, cavity wall naturally-ventilated homes during the winter following an energy efficient retrofit. As part of the energy retrofit, homes received new windows and doors, an upgraded heating system, attic insulation, and wall vents, as well as pumped beaded wall insulation into three external walls.

The current type of construction preferred for new high energy efficient buildings in Germany, featuring highly insulated building components and an almost completely airtight building shell, raises several new challenges with regard to design, construction and use of these buildings. Cooling, in particular, is an issue that gains importance also in the residential sector, in connection with rising temperatures induced by the climate change.