In the EU Joule project Nat Vent one of the work packages was dealing with controlled air flow inlets. During the last conference in Greece and overview was presented on availability, performances and application of controlled air flow inlets. At the presented poster an interactive IAQ computer tool was demonstrated. This tool has been improved and is now available. Some participating countries in the Nat Vent project have carried out special tests with the NatVent IAQ tool. The NatVent participants were asked to design a natural ventilation system according to their national requirements.
Measured contaminant and heat removal effectiveness data are presented and compared for a 3: 1 scale model room, which represents a smoking room, lounge, or bar with a two dimensional airflow pattern. In the experiments, heat and tracer gases were introduced simultaneously from a source to simulate a prototype smoking room. High-side-wall and displacement ventilation schemes were investigated, and the latter employed two different types of ceiling diffuser, low velocity slot and low-velocity grille.
The large heat loss from Passive-stack ventilation (PSV) systems quite often makes natural ventilation systems unattractive and it is therefore desirable to implement heat recovery in PSV stacks. As the stackpressure is usually about a few Pascal, it is crucial that the heat recoveryunit used in a PSV system produces even lower pressure loss, which is extremely difficult to achieve with the conventional plate heat exchangers. This work is concerned with an a low pressure-loss heat recovery device based on heat pipes.
This paper will describe a proposal to upgrade a thermally sub-standard multi-storey housing block (Type T84), where height and climatic exposure are significant, to demonstrate the effectiveness of passive, active and hybrid solar techniques to minimise space and water heating loads while enhancing the quality of air in both shared and private spaces.
In order to understand why Mechanical Ventilation with Heat Recovery is common in some countries of Europe yet installed in a small minority of domestic dwellings in the UK, surveys of Regional Electricity Companies and distributors have been carried out to identify whether there are grants available to promote the system in the UK and what influences sales of the system across Europe. A review of other heat recovery systems is provided to assess whether they are competitiors.
Heat recovery is difficult to implement in passive stack ventilation because the pressure loss is usually too high in conventional heat exchangers compared with the stack pressure. Laboratory investigation and computer simulation have been carried out on a low pressure-loss heat recovery device based on heat pipes which is suitable for application in passive stack systems and other systems where a low pressure loss is essential. It was found that heat recovery efficiency decreased with increasing air velocity.
Numerous ground-coupled air systems have been constructed in combination with heat recovery units in mechanically ventilated buildings in Switzerland. The objective of this study was to investigate the microbial content within these ventilation systems and to monitor the quality of the air supply. The concentrations and the types of microorganisms in the outdoor air, in the air of the pipes and in the supply air of twelve groundcoupled air systems were determined. In addition, three buildings were examined four times a year to cover seasonal changes.