Forced air distribution systems in residential buildings are often located outside conditioned space, for example in attics, crawlspaces, garages and basements. Leaks from the ducts to these unconditioned spaces or outside can change flows through the registers and change the ventilation rates of the conditioned spaces. In this study, duct leakage flows were measured in several low-rise apartment buildings. The leakage flow measurements and other data about the apartments were used to develop a prototype apartment building.

ASHRAE has recently published its first residential ventilation standard, Standard 62.2-2003. This standard defines the roles of and minimum requirements for mechanical and natural ventilation systems and the building envelope intended to provide acceptable indoor air quality in low-rise residential buildings. The standard includes a minimum whole-house ventilation rate, local exhaust rates and other kinds of source control. This report summarizes the standard and indicates the key issues.

Infiltration has traditionally been assumed to contribute to the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Some studies have indicated that application of such a simple formula may produce an unreasonably high contribution because of heat recovery within the building envelope. The major objective of this study was to provide an improved prediction of the energy load due to infiltration by introducing a correction factor that multiplies the expression for the conventional load.

Indoor Air Quality represents a very ambitious challenge in developed countries. As already shown in previous studies, four phenomena are influencing the air pollution level indoors. These are ventilation indoor emissions, chemical reactions in the bulk air-phase of the rooms, and physico-chemical interactions between pollutants and building materials.

Results from 100 apartment buildings built in 1990’s in Finland were compared. Apartment buildings were divided into three main groups; Mechanical exhaust only, mechanical supply and exhaust air systems with heat recovery centralized solutions and de-cent

Fresh air is one of the most important affecting factors for air conditioning system. On one hand, it contributes to good indoor air quality (IAQ). On the other hand, it partly determines the energy consumption of air conditioning system. This paper focuses on the study of IAQ based demand controlled ventilation (DCV) in which CO2 concentration is used as the controlling index of human produced contamination due to the fact that human beings is the main source of indoor CO2, and TVOC concentration is used as the controlling index of building produced contamination.

Positive building pressure with respect to outdoors has been shown to be a positive step to reduce the likelihood of wall moisture problems in hot, humid climates. Exterior wall moisture problems usually result in microbial growth, reducing the health of the building as well as structural degradation of the wall components. However, the test instruments, procedures and reporting methodologies are not provided or recognized in the building design and construction community.

The objective of the paper is to compare central and decentralized air-handling units with regard to costs and suitability. It is mainly based on a calculation model for Life Cycle Costs (LCC), which has been used on two cases, one high-rise and one medium-rise office building. Qualitative evaluation of non-quantifiable factors supports the comparison. The results show that the decentralized solution in general has higher LCC, but buildings with side wings and fewer floors tends to even out the differences.

We present the experimental and numerical study of a plume developed above a heat source both in a stratified and non-stratified medium. This situation arises in industrial facilities with displacement ventilation where air is supplied to the lower zone and extracted at roof level.

This study reports generally low actual air change rates in Finnish houses. Average air change rates in winter were 0.3 ach (11 l/s,pers) in natural, 0.34 ach (10 l/s,pers) in mechanical exhaust and 0.41 ach (13 l/s,pers) in mechanical supply and exhaust ventilation. The prevalence of indoor climate related complaints was lowest within an air change range of 0.3...0.5 ach. At lower air change the prevalence of odors and at higher air change the prevalence of draft and dry air was significantly higher.