Airbase publication

There has been substantial concern about the potential for radon levels to increase in homes undergoing energy retrofits, especially those including substantial air sealing. This study evaluated if precautionary measures could curb increases in radon in over 250 homes receiving energy efficiency retrofits. The goal of these precautionary measures was not to provide full radon mitigation, but rather to avoid increases in radon following retrofit.

People spend approximately 90% of their time within indoor environments, and consequently, characterizing the chemistry of indoor air is valuable from a human health perspective. A simple-to-run indoor air chemistry model is needed as an initial screening tool for public health applications. The Simplified Indoor Air Chemistry Simulator (SIACS), which is currently in development by EPA, incorporates 78 chemical species with 211 chemical reactions and aims to fit this need.

Radon is a naturally occurring gas that is hazardous to human health, making it desirable to minimize exposure. Radon can infiltrate buildings and accumulate to concerning levels, especially in those with tight exterior envelopes and low fresh air exchange rates. Previous research has suggested that air sealing, a common tool for improving building energy efficiency, can increase indoor radon concentrations (Pigg et al. 2017).

This paper reports preliminary analysis from a large field study of 100 university classrooms in Central Texas. Lecture classrooms and auditoriums were sampled for three consecutive weekdays in the 2019 – 2020 academic year. Carbon dioxide (CO2) concentrations, used as a marker for both ventilation and exposure, and temperature were measured in the general room area and when able, the supply airstream. HVAC control data that relates to ventilation was also saved for comparison.

Ventilation and source control (e.g. using low volatile organic compound (VOC) emitting materials) are two recommended approaches to control indoor air pollution and VOC’s in particular. Decisions on how to minimize exposure can be supported by indoor air chemistry modeling, since the relationships between VOC’s, their precursors, and building ventilation is so complex. For example, modeling could be used to examine the impact of altering building ventilation.

PCM (phase change materials) is an innovative technology and an effective method for improving the thermal mass of buildings owing to it possesses the property of large thermal capacity within a limited temperature range, which is similar to an isothermal energy tank. However, most of the previous studies focused on the combination of PCM and walls that the utilization potential of rooftop is lack of concern though there is a significant amount of heat gains from rooftop.

Responding to the hot humid climate, the Taiwan government expects to broadly install air-conditioning in classrooms to provide a comfort study environment for school buildings and prevent the risk of overheating; therefore, corresponding to the installation of air-conditioning, it is important to draw up the energy-saving strategy while considering the thermal comfort.

Portable air cleaners have demonstrated their effectiveness in reducing indoor PM concentrations. Common rating systems assume the air cleaner is in a room having limited air exchange with ambient air and the rest of the building. In this analysis, we model conditions in which people operate air cleaners in rooms with some natural ventilation. METHODS: A simplified mass balance model was developed for a 50 m3 room within a 350 m3 home, assuming well-mixed spaces, homogeneous infiltration, and applying the LBLX ventilation model.

In this study, questionnaire survey and field measurement were conducted for the houses with the elderly in urban and rural areas across 6 regions of China, during heating period. As the results, the prevalence of hypertension was found around 40% in both urban and rural areas. In the northern regions, the room temperature in urban residences was stable at around 20°C, and in rural areas this temperature rarely reached 20°C but it fluctuated greatly.

The current research investigates the relative humidity conditions in Swedish dwellings (678 apartments and single-family houses), comparing measurements from the 2007/2008 BETSI-survey (heating season), with the recommendations of the EN 16798:2019. Analysis shows that 61.4% of the apartments and 29.8% of the single-family houses belong to Cats. 3 and 4, which correspond to moderate and low level of expectation, respectively (mainly due to low relative humidity).