English

Ekoporten, a block of flats converted into an experimental sustainable building, is now 2+1/2 years old. The building is one of the most visited and debated projects carried out in Sweden in recent years. With the support of the Swedish Council for Building Research, researchers from the Faculty of Architecture, Royal Institute of Technology, Stockholm (KTH) have followed up and documented the experiment.

The laminar flow for a backwards facing step is studied. This work was initially part of the work presented in [l]. In that work low-Reynolds number effects was studied, and the plan was also to include laminar flow. However, it turned out that when the numerical predictions of the laminar flow (Re= 118) was compared to the experiments of Restivo [2), we found a large discrepancy. We believe that there is something wrong in that experimental investigation.

The principal soil gases of current concern to building are radon and landfill gas. The flow of these is generally thought to be dominated by viscous flow driven by pressure differences. This paper compares analytical results presented in two previous papers, an experiment to measure the flow of gas in soil and an analytical result found by another technique. The results support the findings of the previous work.

The principal soil gases of current concern to building are radon and landfill gas. The flow of these is generally thought to be dominated by viscous flow under a pressure gradient. This paper presents results for such pressure-driven flow of gas for problems relating to a building with a bare soil floor, for example below a suspended timber floor. The solutions address this problem in two dimensions as a mixed boundary problem.

The principal soil gases of current concern to building are radon and landfill gas. The flow of these is generally considered to be dominated by viscous flow driven by pressure differences. This paper presents results for the pressure-driven flow of gas for problems relating to a building with a bare soil floor, for example below a suspended timber floor. This paper builds on a previous paper by mapping the solution to a mixed boundary problem onto another geometry. In a third paper these results will be compared with an analytical result from elsewhere and an experiment.

The ventilation air intake (louver) is the first line of defence against an unfavourable outdoor climate. Unfortunately, the importance of this component is often an underestimated issue in the design process of many heating, ventilation and air conditioning (HVAC) systems. Field studies and inspections of a representative number of HVAC plants carried out between 1995 and 1998 in and around the city of Trondheim revealed that snow, and in several cases rain, easily passes through the air intake louver. Such intrusion of humidity can lead to unwanted microbial growth in the HVAC system.

In mechanical exhaust ventilated buildings in cold climates, the supply air through vents in the perimeter may cause draught and reduce the zone of occupancy. One way to prevent this is to preheat the outdoor air by a vent-convector. An experimental study of the performance of a vent-convector is reported in this paper. Measurements have been conducted in a test room and in a school equipped with vent-convectors. Air flow and pressure drop characteristics were investigated for one type of vent-convector. the temperature variation at a step change of the air flow was also investigated.

Suitable combinations of desiccant and evaporative cooling systems permit air processes alternative to the traditional ones for air conditioning applications. But owing to the high costs of desiccant wheels, we need very strong energy savings in order to demonstrate an economy validity. These savings can be possible today by the last generation of desiccant wheels where the most part of the regeneration heat can be supplied by heat recovery from chillers.

This field study was organised to track differential pressure relationships in critical care units of a metropolitan hospital. Maintaining design pressure balances is essential to control risk of airborne disease transmission within these units. the pressure differentials that exist between two patient isolation facilities (positive and negative) and their surrounding spaces were monitored continuously for one week.