English

In modern apartment buildings with good insulation and heat recovery, often having large windows and high internal heat gains, overheating may be a serious problem not only in summer season, but also during heating season. This study determined the design curves for the assessment of room temperatures and cooling demand in apartments. The design curves are based on many simulations and they show the effects of window airing, solar protection glasses, window size and orientation, cooled supply air and room conditioning.

A subjective experiment was conducted using 15 college-aged subjects of both genders in order to evaluate their physiological and psychological reactions, performance and fatigue under the different combinations of indoor humidity, local air velocity and illuminance.

The purpose of this study is to evaluate the relevance of household characteristics on exposure time to CO2 in houses with balanced ventilation. Statistical tests were conducted to measure the significance of household differences on time indoors. Household scenarios and ventilation scenarios were constructed to determine the level of CO2 indoors. The production of CO2 was calculated with the metabolic rate per age of the members of the household. Households are exposed to levels of CO2 higher than 1000 ppm in houses with low infiltration rate.

The life cycle cost (LCC) of the heating and ventilation system was simulated for a typical multi family dwelling and a typical detached house. Different ventilations systems were simulated resulting in different heating system designs. A health related cost dependent on the airflow rate which was based on recent studies was added to the life cycle cost. The health related costs are not analyzed but varied in a parametric study. An optimal airflow rate can be found depending on the assumed size of the health related cost.

The significant public health effects of ambient air pollution are mostly caused by exposures in indoor environments, where we spend over 90 % of our time. Indoor concentrations of air pollutants are in general higher than and often also independent of the outdoor air concentrations. In average, urban outdoor air contributes significantly to indoor concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), benzene and some other aromatic VOC:s, ozone (O3), and fine particulate matter (PM2.5), but not to, e.g., most VOCs and carbonyls or to the highest concentrations of CO and PM.

Small energy efficient fans have become commercially available for use in HVAC-systems; this open up new possibilities for alternative design of air distribution systems. In this paper the effect of integrating small fans in duct systems is investigated. Modelling and measurements shows that this design has the potential to save energy. When integrating fans in a duct system it is important to consider the system as a whole to find the most energy efficient system solution.

This article examines the effectiveness of air cleaners ranging from portable to duct-mounted devices and lists a variety of technologies that claim to remove particulate matter, chemicals/odors, VOCs and other pollutants. Determination of performance indices and summary of test results are presented.

In this article, models for estimating how the indoor environment quantitatively affects sick leave and work performance are presented. Working environment, facility services, personal motivation, psychological aspects are factors, other than IEQ, that affect work performance too.

Standard 62 was first published in 1973, the latest version designated as 62.1 was published in 2004 . Throughout its existence, that standard has generated controversy on the one hand and has served the building industry for ventilation and IAQ on the other hand. This article attempts to explain some of the concerns regarding that standard, and to counter some of the issues that have been raised.

Ultrafine particle (UFP) exposures can cause oxidative stress and inflammation in the lungs. The objective of that study was to examine the contribution of home heating systems such as electric baseboard heaters, wood stoves, forced-air oil/natural gas furnace, to indoor UFP exposures. The results of the cross-sectional survey conducted in 36 homes in the cities of Montreal, Quebec and Pembroke are presented. The authors' findings suggest that home heating systems are not important determinants of indoor UFP exposures.