The applicability of displacement ventilation for individual control of a microclimate

This paper introduces the desk displacement ventilation concept, which combines displacement ventilation with task conditioning. The experimental setup and results of full-scale steady-state and transient measurements and numerical simulations are described for a typical office configuration. Results are used to evaluate the concept with regard to the micro/macroclimate and thermal comfort. The steady-state results show that the separation between the micro- and macroclimate, which is characteristic of task conditioning, is less pronounced and may require improvement of the concept. This effect is investigated further via transient experiments. Results of the transient study show that the application of the displacement ventilation principle for task conditioning purposes is not suitable for standard office configurations. It should at least be supported by an additional system that introduces the air at higher velocity close to the occupant, of which several system types are already available today.</p

The influence of indoor air quality in classrooms on the short-term academic performance of students in higher education; a field study during a regular academic course

The indoor air quality (IAQ) in classrooms in higher education can influence in-class activities positively. In this context, the actual IAQ and students’ perceived IAQ (PIAQ), perceived cognitive performance (PCP), and short-term academic performance (SAP) were examined in two identical classrooms during regular academic courses. During the lecture, key performance indicators (KPI) for the IAQ, i.e. carbon dioxide concentration, particulate matter 2.5, and total volatile organic compounds, were measured. After the lecture, responses of 163 students were collected with a validated self-composed questionnaire and a cognitive test, which covered topics discussed during the lecture. A significant association between the IAQ KPI and the PIAQ was found (p < .000). The PIAQ significantly predicted the PCP (p < .05) and the PCP significantly predicted the SAP score (p < .01). These results indicate that the IAQ in classrooms is associated with the PIAQ and PCP, and therefore is associated with students’ SAP.publishedVersio

Emission rates of bio-based building materials, a method description for qualifying and quantifying VOC emissions

Biobased insulation materials offer opportunities to use vapor-open building constructions. Such constructions allow direct interaction between the biobased material and the indoor environment. This interaction raises questions about indoor air quality concerning volatile organic compounds (VOCs). This study presents results for the VOC emissions from biobased materials. It consists of two parts: 1) qualification of VOC emissions (compounds) from several biobased and non-biobased building materials, and 2) quantification of VOC emissions (emission rate) from expanded cork (biobased), particle board (semi-biobased), and EPS insulation. By quantifying the emission rate, the exposure to the released VOC emissions at room temperature in a standardized room can be compared to health limit requirements. Gas chromatography and mass spectroscopy (GC–MS) is used to derive the individual VOC emissions and the Total Volatile Organic Compounds (TVOC) from these materials. For qualification, two different sampling techniques are used in which temperature is introduced as a variable to investigate its effect on the type of compounds emitted. For quantification, the toluene equivalent approach is compared to the group equivalent approach. From the analyses it is concluded that temperature has an effect on the type of VOC compounds emitted from (biobased) materials. Results from the quantification indicate that expanded cork and particle board emit no harmful substances at a level that can affect human health. For EPS insulation, elevated levels of benzene were found to exceed healthy limits. The toluene equivalent approach for quantifying the emission, generally, underestimates the rate as compared to the more accurate group equivalent approach

The influence of indoor air quality in classrooms on the short-term academic performance of students in higher education; a field study during a regular academic course

The indoor air quality (IAQ) in classrooms in higher education can influence in-class activities positively. In this context, the actual IAQ and students’ perceived IAQ (PIAQ), perceived cognitive performance (PCP), and short-term academic performance (SAP) were examined in two identical classrooms during regular academic courses. During the lecture, key performance indicators (KPI) for the IAQ, i.e. carbon dioxide concentration, particulate matter 2.5, and total volatile organic compounds, were measured. After the lecture, responses of 163 students were collected with a validated self-composed questionnaire and a cognitive test, which covered topics discussed during the lecture. A significant association between the IAQ KPI and the PIAQ was found (p < .000). The PIAQ significantly predicted the PCP (p < .05) and the PCP significantly predicted the SAP score (p < .01). These results indicate that the IAQ in classrooms is associated with the PIAQ and PCP, and therefore is associated with students’ SAP.publishedVersio

Assessment of the performance of the AirTulip headboard prototype

This report describes the outcomes from experimental research into the performance of the prototype headboard as developed by AirTulip. Through measurements in a laboratory set‐up the Local Air Quality Index at the head level of a sleeping person, the air cleaning potential to support the general ventilation in- the sleeping room and the potential for draught complaints has been investigated

Assessment of the performance of the AirTulip headboard prototype

This report describes the outcomes from experimental research into the performance of the prototype headboard as developed by AirTulip. Through measurements in a laboratory set‐up the Local Air Quality Index at the head level of a sleeping person, the air cleaning potential to support the general ventilation in- the sleeping room and the potential for draught complaints has been investigated

Exploring the effects of indoor air quality on sleep and sleep quality of older people

We all are familiar with the phenomenon that when having a bad night's sleep we feel lousy the next day. This is also the case for people with dementia. We received a cry for help from a family carer claiming that his spouse with dementia displayed agitation and other symptoms of Behavioral and Psychological Symptoms of Dementia (BPSD) after a bad night while being exposed to poor indoor air. Nurses and family caregivers do report that some BPSD problems occur when heaters/air-conditioners are not switched on sufficiently early enough to maintain a comfortable indoor thermal environment (Wong et al., 2014). In a case study by Cremers (2015) findings showed that restlessness behavior (apnea, panic, humming) is observed in a person with dementia during the night when CO2 levels in de bedroom exceed 800 ppm. Poor indoor air quality (IAQ), measured via carbon dioxide (CO2) as a proxy, has a negative effect on people’s health and performance (Wyon & Wargocki, 2013; Allen et al., 2016). Furthermore, it is known that bedroom air quality relates to sleep quality and next-day performance in healthy young adults (Strøm-Tejsen et al., 2015). Little is known though about the influence of indoor air quality on persons with dementia. To explore this, we first wanted to reproduce the study of Strøm-Tejsen, before moving to involve ageing people because of ethical and practical reasons