Procedure for Balancing an Air Distribution System with Decentralised Fan

This paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally introduce pressure drops in the duct system thus nominal airflows are achieved throughout the ductwork within specified tolerances.

Sanitary aspects of domestic ventilation systems: An in situ study

With the continuous improvement of the energy performance of buildings, ventilation plays a crucial role in the control of pollutants from indoor sources and related comfort and health effects. However, the ventilation system itself could possibly also be a source of indoor air pollutants such as microbial contaminants. Profound scientific and technical knowledge on the impact of the design, installation and maintenance on the real performances of ventilation systems is currently lacking.

Hybrid ventilation – the ventilation concept in the future school buildings?

Hybrid ventilation (HV), as a combination of automated natural ventilation (NV) and balanced mechanical ventilation (MV), provides opportunities to use the advantages of both ventilation systems during the seasons in order to reduce energy demand and at the same time obtain comfortable indoor climate.

Residential ventilation system performance: Outcomes of a field study in the Netherlands

This paper describes the results of a Dutch national study into performance of mechanical ventilation systems and its effect on the self-reported health and perceived indoor environmental quality of occupants.

Performance of low pressure mechanical ventilation concept with diffuse ceiling inlet for renovation of school classrooms

In a great portion of Danish primary schools the mechanical ventilation systems is outdated or simply rely on opening of windows to ventilate the classrooms. This leads to high energy consumption for fans and/or ventilation heat losses and poor indoor environment, as the ventilation systems cannot provide a sufficient ventilation rate. A recent study with 750 Danish classrooms show that 56 % had CO2-concentrations over a 1000 ppm, which is the recommended limit by the Danish working environment authority and this adversely affects the performance and well being of the pupils.

Performance Potential of Mechanical Ventilation Systems with Minimized Pressure Loss

In many locations mechanical ventilation has been the most widely used principle of ventilation over the last 50 years but the conventional system design must be revised to comply with future energy requirements. This paper examines the options and describes a concept for the design of mechanical ventilation systems with minimal pressure loss and minimal energy use.  This can provide comfort ventilation and avoid overheating through increased ventilation and night cooling.


Total heat exchanger model based on experimental results was incorporated in the entire buildingmodel with the stay and internal generation of heat and with window opening-closing schedule, andenergy-saving effects of total heat exchangers were evaluated including regional features in Japan.Regional differences were found in the effects, and it was found that the reduction rate of heating andcooling loads was in the range of about 2 15%, and the reduction amount of heating and coolingloads was in the range of about 0.1 11 GJ.

Study on Performance Evaluation of Mechanical Ventilation Systems for Occupied Houses

In the first phase of the current project, the ventilation rates of occupied houses in the northern region of Japan were investigated from 2001 to 2005. It was revealed that, despite installing mechanical ventilation system, low ventilation rate was found in many houses. The causes were believed attributing to lack of cleaning of grills, filters and insect protection meshes. The second phase of the project was to investigate the causes and resolve the problems. This project was started in 2005 and 12 houses installed with mechanical ventilation system were investigated.

Numerical Evaluation of Earth to Air Heat Exchangers and Heat Recovery Ventilation Systems

Balanced ventilation systems with heat recovery and earth to air heat exchangers are interestingtechniques, which can reduce heating and cooling demand of buildings, and improve internal thermal comfort. A numerical study is carried out to evaluate the impact of these two systems on the energy consumption and thermal comfort of a single family house. The impact on the CO2 emission is also given.

Ventilation performance measurement using constant concentration dosing strategy

For that study, the constant concentration dosing method and the decay method were used to test air changes performances in an office equiped with a VAV mechanical ventilation system and in a domestic apartment with natural ventilation . The measurement results from those two tracer gas methods are compared.