refurbishment

The aim of the European SSHORT (Sustainable Social Housing Refurbishment Technologies) project is to increase and promote rational and efficient use of energy in the retrofitting of social housing buildings. In this scope, one step was to evaluate with simulation studies the technical and economical interest of selected sustainable technologies on standard collective social housings in participating countries.

Thermal bridges are the typical locations for moisture and mould problems in buildings. Low surface temperatures in combination with a high humidity level in buildings can lead to severe problems and complaints by the occupants. Thermal bridges lead also to a significant increase of the energy losses in well insulated buildings. At present, thermal bridge problems still frequently occur in new buildings but especially in rehabilitation projects. In several countries so-called thermal bridge atlases already exist.

This article describes a ventilation system, developed within the framework of aEuropean project supported by the JOULE III programme (NAVAIR project). Theconcept used - natural ventilation assisted by air induction combines the advantages ofnatural ventilation and the performances of mechanical ventilation.

A case study of the ventilation characteristics of office accommodation forming part of a recently refurbished building is presented. A mechanical system has been installed to ventilate and cool two floors that are interconnected by a series of atria, with a novel application of displacement ventilation applied where there is a very low ceiling height. The air distribution and air quality within the space have been studied by the application of computational fluid dynamics (cFD) to allow the computation of air change effectiveness in terms of local mean age.

Many existing offices either overheat in the summer or use excessive amounts of energy to maintain acceptable temperatures. The reasons are increasing internal heat gains from office IT equipment, poor efficiency lighting systems, density of staff and original poor building design causing excessive solar gains. The trend is for problem offices to have AC systems replaced - at the end of the life of the existing services - or installed in previously naturally ventilated offices when refurbishment occurs.

The Manchester Project involved the energy efficient rehabilitation and retrofitting of existing housing units plus the construction on vacant lots of new dwellings incorporating energy conservation measures. This project, in the Manchester neighbourhood of Pittsburgh, Pennsylvania, began inthe late 19 70s and was completed in 1983. Energy use and air quality monitoring were carried out for one year after the completion of the project. It was found that in comparison to detached single-family houses using standard construction, energy savings of 75 to 80% were being realized.