PR2017

The airtightness of buildings is important for several reasons, such as being a prerequisite for low-energy buildings and for a healthy indoor air quality (without i.e. mould or radon). The airtightness of buildings can vary over time and investigations are made on these variations due to moisture induced movements in wooden constructions, and subsequent consequences, using both measurements and numerical simulations.

In the Framework of the IEA EBC Annex68 Subtask 1 working subject, we aimed at defining an indoor air quality index for residential buildings based on long- and short-term exposure limit values. This paper compares 8 indoor air quality indices (IEI, LHVP, CLIM2000, BILGA, GAPI, IEI Taiwan, QUAD-BBC and DALY) by using the French IAQ Observatory database that includes pollutant concentration measurements performed in 567 dwellings between 2003 and 2005. This comparison allows to make a relevant analysis of each index and determines their pros and cons i.e.

With the combination of two fans and a heat exchanger in one single component there is the possibility to design a compact and highly efficient ventilation system especially for use in building modernization. One crossflow fan generates both airflows (outdoor/supply and extract/exhaust air) and simultaneously acts as counterflow heat exchanger. The space between the fan blades is filled with elements which operate as regenerative heat exchanger. The modified laboratory prototype of the so called Counterflow Heat Recovery Fan was optimized for the use as single/double room unit.

When considering the performance of HRV systems, the discussion is generally focusing on the reported effectiveness of the air-to-air heat exchanger. Although some excellent presentations at the AIVC conference in the past have dealt with uncertainties related to the test of that effectiveness, the fact that the heat recovered by the HRV unit might not be useful in an intermittently heated dwelling without room-by-room based demand control is usually not considered. Therefore, the ‘use-factor’ for the recovered heat is quantified in this paper.

Residential ventilation standards, especially in Europe are slowly but substantially moving away from their usual prescriptive approach towards performance based specifications. While academics and policy makers argue about the relevant IAQ indicators, housing developers and end users need to make a choice between the different ventilation system options they are faced with in the market. Although several IAQ rating systems have emerged, a comprehensive assessment method to rate the inherent qualities of the ventilation system itself is not available [6].

Over the last decade, TVOC sensors have been touted as an interesting alternative to CO2 and RH sensors in DCV systems. Nevertheless, there is little evidence on the nature and the profile of TVOC concentrations in modern dwellings.

Balanced ventilation with heat recovery is an efficient way to maintain low heating demand for ventilation in residential buildings. Laboratory measurements of today’s heat recovery ventilation units show high temperature recovery efficiency during standard conditions. In practice, however, the recovery efficiency may decrease due to circumstances that deviate from the standard laboratory conditions.

Combining heat recovery with natural ventilation is a relatively new topic of significant academic and commercial interest. The present study shows the performance of a recently developed Passive Ventilation system with Heat Recovery (PVHR) installed in a primary school building.

In the present paper the impact of natural cross-ventilation on thermal comfort levels in sustainable residential buildings is evaluated. A sustainable dwelling is designed in Crete and various scenarios of different combinations of open windows and doors in the ground floor, the first floor and between the floors are tested to determine the final scenarios with the best possible airflow movement.

Demand controlled ventilation (DCV) can improve the energy performance of all kinds of ventilation systems, in residential and non-residential buildings and is already part of the European Lot 6 and Ecodesign regulations and standards. However, the lack of recognition of DCV in SAP (Standard Assessment Procedure) forms a great barrier for the use of this technology in the UK. A methodology was developed to prove the guarantee on good IAQ, with potential saving on heating and auxiliary energy by modulating ventilation rates based on actual demand.