English

Energy losses from forced air distribution systems have a significant impact on the energy efficiency of buildings. Little work has been done to quantify these losses in apartment buildings. In this paper we will discuss field measurements made on four forced air heating systems to evaluate the duct system energy losses to unconditioned basements. The apartments were heated by natural gas furnaces located in the basements. The systems had bare sheet metal ductwork exposed to the basement conditions.

This report is the result of a survey that has been carried out 1989 in compliance with the work within CIB Working Commission W57 Building Documentation and Information Transfer, Working Group 11 (WG 11 ). Two earlier editions of the report has been published as a result of a survey 1986.  This third edition contains entries from 44 countries out of which 11 are new entries and 20 are updated compared to the earlier editions. Responses from previous survey (1986) are included for those countries wich has failed to respond to the 1989 survey.

Carbon dioxide included in exhaled breath is often used as a tracer gas when estimation of ventilation aspect in buildings with occupants is performed. Carbon dioxide produced by occupants is the key for the estimation. JIS A 1406 and ASTM D6245-12 refer personal carbon dioxide production rate. However JIS does not take into account personal attribute like as body height and weight. On the other hand, ASTM does not take into account gender difference and based on average westerner adult data.

Adopting natural ventilation as a retrofit strategy for cooling, due to the low impact nature of the installation, is attractive due to the cooling potential of untreated outdoor air for large periods of the extended cooling season, particularly in northern climates. In line with this it is important to characterise the performance of natural ventilation components in low energy buildings in successfully transferring the cooling potential of outdoor air to the occupied zone.

The trend towards more nearly zero energy buildings and much more airtight buildings represents specific challenges for cooker hoods in residential buildings. 

There is a trend to perform more ventilation and air infiltration measurements in buildings, either to strengthen commissioning procedures or to learn from field data. This trend is stronger in nearly zero-energy buildings projects or programmes given the significant share of ventilation and infiltration losses on total building energy use.

An increasing number of countries (e.g. Czech Republic, Denmark, France, Germany, Ireland, Netherlands, Norway, Portugal, UK) include in their regulations either required or recommended minimum airtightness levels with or without mandatory testing. The number of tests performed on a voluntary basis is rapidly increasing either because of the energy penalty for untested buildings in the calculation method or due to the specific requirements of a given program. Furthermore, mandatory testing came gradually into force in the United Kingdom, Portugal, Denmark and France.

There exist several initiatives in different parts of the world to bring a stronger basis to ventilation requirements in relation to indoor air quality and health issues, for example, at LBNL in the US (Healthy efficient homes program), within the HealthVent project in Europe (2010-2012), at Health and Wellbeing project in Japan, Development of healthy and clean residential building standard in Korea (2008-2012) or within the French Observatory for Indoor Air Quality (running since 2001).