English

The performance of three different ventilation systems in cold climate homes is discussed. Comparisons are presented of monitored datasets by contrasting operations of the three ventilation systems, the energy impacts on the overall HVAC systems, and resulting indoor environmental conditions. Whole building simulation results, based on ventilation system models using EnergyGauge and validated in part by the monitored datasets, provide normalized comparisons of HVAC system energy use.

A field study in 18 selected houses in Dublin and the surrounding area has been carried out between September 2004 and February 2005Continuous measurements of Indoor temperature, relative humidity (RH), concentrations of selected pollutants including carbon dioxide (CO2), carbon monoxide (CO), particulate matters (PM1, PM2.5, PM7 and PM10), moisture, and ozone (O3) were made in each house. The infiltration rates in ten houses were tested with both fan pressurization and tracer gas decay methods. The results of those investigations are presented.

In this study, personal displacement ventilation (PDV), including two cases with all seats taken and two middle seats taken, is compared with overall displacement ventilation (ODV) of all seats taken under the condition that supply temperature is 24C and air change rate is 60 l/s per workstation. The results indicate that PDV can be used in the room with big change of occupants number to satisfy the need of thermal comfort and air quality. When not all seats are taken, designers should increase supply air requirement or reduce its temperature for thermal comfort.

For that study, an investigation of indoor air microbes of two Hong Kong Old Folks Home, one with naturally ventilation and another with mechanically ventilation device, was carried out. Samples of airborne fungi and bacteria were taken from five indoor sites characterized by different human activities along with an outdoor sample for comparisonBoth bacterial counts and fungal counts in air in the naturally ventilated Home were higher than that in the mechanically ventilated Home.

An experimental and a numerical studies were performed to compare thermal comfort(TC) and indoor air quality(IAQ) in the lecture room for cooling loads when the operating conditions are changed. PMV value and CO2 concentration of the lecture room were measured and compared with the numerical results. They had a good agreement with each other. Then the authros used their numerical model to analyze TC and IAQ for a couple of operating conditions. The results are presented.

The individualized control air conditioning mode can meet different needs of occupants to a greater extent than the traditional total-space air conditioning mode.In this paper, the authors consider that the total supply air system with variable air volume (VAV) box is appropriate to provide acceptable comfort and good indoor air quality.

Data linking poor IAQ in the classrooms to student performance is limited. This study explores the student performance on standardized aptitude tests that are administered to students on a yearly basis,in parallel with classroom carbon dioxide concentrations. Data on classroom conditions and carbon dioxide concentrations (were recorded in 5th grade classrooms in fifty four schools within a Midwestern school district in the USA. Preliminary results are presented in the paper.

A draft perception study of Displacement Ventilation (DV) system in a Field Environmental Chamber (FEC) with tropically acclimatized subjects is presented in this paper.60 subjects, 30 males and 30 females, were exposed to 3 vertical air temperature gradients, and 3 room air temperatures, for a 3 hour-period. Room air temperature had greater impact on percentage unsatisfied due to air movement than temperature gradient.

Subjective experiments were conducted to investigate the effect of three different types of Task air-conditioning systems (3DU+, PEM, and TU) on thermal comfort in a climate chamber - conditioned at 28C/50%RH with task systems and 26C/50%RH without them.- It was found that these systems were effective in providing thermal comfort.

How much do we really know about ventilation ?It is admitted that for a good indoor air quality in a building, the amount of outdoor air ventilation is one of the most important determinants , but many critical questions and misunderstandings exist :Do we know the quantity of outdoor air is even needed in buildings? And about the ventilation requirements : they treat all the huge variability in buildings the same.