PR2019

Energy use in buildings has a significant influence on the global energy demand and environmental impacts. Among all building systems, heating, ventilation, and air conditioning (HVAC) systems are the most energy-intensive in terms of their total energy requirements. The production and operation of HVAC systems have a significant impact on the environment. These systems are also among the largest consumers of natural resources and materials in the building sector.

The indoor thermal comfort and air quality in classrooms have become of interest worldwide, predominantly because of their influence on children’s health, learning performance and productivity. Growing concerns with building energy efficiency emphasize the significance of this topic. This paper illustrates the outcome of a field study conducted in secondary school classrooms in Sydney, Australia, during the school year in 2018/2019.

This study aims to assess the indoor thermal and environmental quality of low-income households in New South Wales, Australia. It adds evidence-based findings on the performance of residential buildings and contributes to improving the indoor environmental quality of social housing. The research presented in this paper involved subjective and objective evaluation of indoor air and environmental quality.

In Switzerland, 70 % of building refurbishments are realised in stages. When only a window replacement is done, the new airtight windows can lead to a reduced infiltration air exchange and subsequently there may be moisture issues, e.g. mould. The integration of passive window ventilation openings (PWVO) with additional exhaust fans in the kitchen and bathroom(s) can ensure a user-independent basic air change rate. PWVO can be defined as small air inlets integrated in or near the window frame.

The new schools in Canada are designed to improve indoor environment quality while achieving a much better energy performance than the code compliance requirements.  

People spend the majority of their time in their own homes and so the indoor environmental conditions are an important determinant of population health and wellbeing and have economic consequences. Chile is undergoing rapid economic growth and is managing its national energy demand to minimize its greenhouse gas emissions. Its housing stock is growing rapidly, and is responsible for 15% of national energy demand. Accordingly, there is a need to understand the performance of the stock by measuring parameters that indicate air quality, thermal comfort, and energy demand.

As newer homes are being built tighter than the existing housing stock, questions have been raised about the concentrations of pollutants of concern in new homes and how mechanical ventilation systems can address this issue. This study measured pollutants of concern in 70 new homes with mechanical ventilation in California, USA and compared the results to a previous study of home without mechanical ventilation. The key pollutants were measured using both time-integrated and time-resolved over a one-week period and included formaldehyde, PM2.5 and NO2.

Due to the wind induced pressure, different results may be obtained if the inside-outside pressure difference is measured across different locations on the building envelope, i.e. if the external pressure tap of a differential pressure sensor measuring this pressure difference is placed in different positions. Therefore, the position of the external pressure tap may influence an airtightness test result as well.

This paper discusses two particular points of the buildings airtightness measurement method (ISO 9972) in relation with the pressure difference: (1) the nature of the pressure tap and (2) the place of the pressure tap outside. 

Uncertainties in airtightness measured using fan pressurization test should not be defined by the scattering of the points around the line defined using ordinary least square method anymore. Its definition requires first to know the uncertainties in pressure and airflow measurements. This works aims at quantifying one of the component of the envelope pressure uncertainty: the uncertainty in zero-flow pressure approximation due to short-term fluctuation of wind speed and direction.