This paper demonstrates that the distribution and area of ventilation openings affects significantly the air flow rates in a hybrid ventilation system.

The use of a hybrid cooling system using radiant cooling panels with wind-induced cross ventilation is described in this paper. Its performance is compared to the hybrid system using underfloor air-cooling. The radiant cooling panels system appears more energy efficient and brings more thermal comfort than the under-floor air cooling system.

This study was undertaken in IEA ECBCS Annex 35 to model a hybrid-ventilated room and to implement control strategies. An experimental cell was designed and simulations were performed after having adjusted the thermal models to experiments. The hybrid ventilation proved more performant than traditional ventilation systems.

Sixteen countries world wide have participated to this international programme (IEA ECBCS Annx 35) running from 1998 to 2002 about "Hybrid ventilation in new and retrofitted office buildings" . All results of the project are published in a booklet and a CD ROM. They have also be published onthe AIVC CD (see AIRBASE recording number 14923).

A poor ventilation in buildings costs considerable amounts of money for hospitals and businesses.10 % of hospital acquired infections are directly due to an airborne route. The quantity and the quality of air supplied is important but also the way it is introduced into spaces. A change of the Wells Riley equation (establishing a link between the likelihood of infection, the infective agent production rate, the exposure time, the pulmonary and room ventilation rate) is proposed to take into account ventilation eefectiveness.

This paper gives the results of a field study in Danish office spaces with displacement ventilation systems. Draught was identified as a serious problem. Half of the 227 occupants were not satisfied with indoor air quality. Occupants counteract draught discomfort in blocking air supply diffusers or asking the maintenance staff to increase the supply air temperature. So a very careful design for displacement ventilation is required in order to perform satisfactorily in practice.

Thermal comfort for 227 occupants in 8 office buildings with displacement ventilation was investigated. The occupants' thermal sensation was close to the predictions by the PMV index. The main conclusion is that draught is the major local discomfort factor for the occupants, mainly at lower leg. The effect of vertical temperature gradients on occupants local discomfort did not appear as evident.

This paper presents an on-going research programme about the performance of a natural ventilation system in a 3-storey building (with 2 aparments in every floor) in Portugal.

This paper deals with the steady state simulations carried out with the CFD software Flovent along with dynamic building energy simulations using the ESP-r programme applied to three buildings (located in Ireland, Poland and Denmark) intended to be equipped with supply air windows coupled with passive stack ventilation systems. Supply air windows consist of two layers of glazing separated by a ventilated layer. Air enters the cavity at the bottom from outsides and enters the building at the top. Systems design from simulation results is discussed.

Prediction of airflow and pollutant transfers in a simple multizone building may use different approaches such as zonal or nodal modeling methods. This paper proposes to improve the modeling of pollutant transport by coupling nodal and zonal models in the SPARK simulation environment.
Nodal model gives mass airflow rates used as boundary conditions in the zonal model to predict pollutants mass transport. Simulation results are compared with experimental data from the 2 zones testing room Minibat.