1,721,179 research outputs found
The impact of increased airflow rates on indoor temperatures of passive house in The Netherlands
No full textThe increasing number of highly insulated and air tight buildings leads to the concern of indoor environment overheating and related comfort and health issues. This can already happen in a temperate climate as found in the Netherlands. This work studies the ventilative cooling process as a possibility to avoid overheated dwellings. A monitored dutch passive house was modelled in Trnsys and the impact of increasing air flow rates on indoor temperatures was simulated. The most overheated zone was chosen to be analysed. The ventilation rates were set in accordance with the ventilation system available in the house. Three possible ventilation rates were simulated and the results obtained for indoor temperatures were compared with measured data. The occupancy was estimated in accordance with registred CO2 levels and the other heat gains were calibrated based on indoor temperature during winter time. Results indicate that indoor temperatures can be considerably lowered by making use of constant outdoor flow rates during the warm season. However, alternative solutions such as shading devices and passive night cooling might be considered during very warm days, when outdoor temperatures rise above thirty degrees Celsius
The impact of increased airflow rates on indoor temperatures of passive house in The Netherlands
No full textThe increasing number of highly insulated and air tight buildings leads to the concern of indoor environment overheating and related comfort and health issues. This can already happen in a temperate climate as found in the Netherlands. This work studies the ventilative cooling process as a possibility to avoid overheated dwellings. A monitored dutch passive house was modelled in Trnsys and the impact of increasing air flow rates on indoor temperatures was simulated. The most overheated zone was chosen to be analysed. The ventilation rates were set in accordance with the ventilation system available in the house. Three possible ventilation rates were simulated and the results obtained for indoor temperatures were compared with measured data. The occupancy was estimated in accordance with registred CO2 levels and the other heat gains were calibrated based on indoor temperature during winter time. Results indicate that indoor temperatures can be considerably lowered by making use of constant outdoor flow rates during the warm season. However, alternative solutions such as shading devices and passive night cooling might be considered during very warm days, when outdoor temperatures rise above thirty degrees Celsius
Vooronderzoek voor een gevoeligheidsanalyse van ontwerp en gebruik van de operatiekamer op de ventilatie-effectiviteit
Get PDFDit artikel presenteert het vooronderzoek voor een gevoeligheidsanalyse van ontwerp- en gebruiksparameters van een operatiekamer over de verspreiding van bacteriën. De gevoeligheidsanalyse is gebaseerd op CFD simulaties om het gedrag van de luchtstromen en de verspreiding van bacteriën te analyseren. Het vooronderzoek bestaat uit een gridgevoeligheidsanalyse en een evaluatie van twee verschillende methoden om de gevoeligheidsanalyse uit te voeren
Percieved control over indoor climate and its impact on Dutch office workers
No full textA field study was conducted in nine modern office buildings in the Netherlands. The study focused on perceived control over indoor climate and its impact on satisfaction of building occupants, the incidence of building related (SBS) symptoms and self-assessed performance.
The study involved a questionnaire amongst 236 office workers. Statistical analyses were conducted to investigate correlations between combined perceived control over temperature and ventilation on the one hand and satisfaction-, SBS- and productivity-indices on the other.
Individual perceived control over indoor climate scores were perfectly normally distributed (using a 7 point scale coded from 1 = no control at all to 7 = full control) with as mean value 3.1 (SD 1.4). Respondents that perceived to have a high amount of control over their indoor climate were considerably more satisfied with their indoor environment. High control respondents also had significant less building related symptoms (BSI(5) 0.94 vs. 0.61). And productivity scores were significantly higher (6.3 %point) in comparison with the low control respondents
Comparison of thermal comfort and sensation scales : a case study
No full textThermal sensation is a conscious feeling that grades the thermal environment, while thermal comfort expresses satisfaction with this feeling. Multiple scales to quantify thermal sensation and comfort have been developed throughout the history of research on thermal comfort. In this paper, the most important scales for measuring thermal sensation are compared and evaluated. Of all scales, the ASHRAE 7-point scale (from cold, through neutral, to hot) is the most common. To measure comfort these scales are often presented together with an acceptability or a comfort scale. Another widely used scale, the Bedford scale uses also 7 points, but combines thermal comfort and sensation by coding from much too cool to much too warm with comfortable in the middle. The preference scale is to use to express whether the respondent would prefer warmer or cooler thermal environment. To compare difference between different thermal comfort scales a case study was conducted, in which a number of respondents were asked to report their thermal comfort. Different scales were presented to the respondents under same thermal environmental parameters. The responses on different scales have been compared. The findings of this study can give a guidance to compare thermal comfort studies using different scales
Comparison of thermal comfort and sensation scales : a case study
No full textThermal sensation is a conscious feeling that grades the thermal environment, while thermal comfort expresses satisfaction with this feeling. Multiple scales to quantify thermal sensation and comfort have been developed throughout the history of research on thermal comfort. In this paper, the most important scales for measuring thermal sensation are compared and evaluated. Of all scales, the ASHRAE 7-point scale (from cold, through neutral, to hot) is the most common. To measure comfort these scales are often presented together with an acceptability or a comfort scale. Another widely used scale, the Bedford scale uses also 7 points, but combines thermal comfort and sensation by coding from much too cool to much too warm with comfortable in the middle. The preference scale is to use to express whether the respondent would prefer warmer or cooler thermal environment. To compare difference between different thermal comfort scales a case study was conducted, in which a number of respondents were asked to report their thermal comfort. Different scales were presented to the respondents under same thermal environmental parameters. The responses on different scales have been compared. The findings of this study can give a guidance to compare thermal comfort studies using different scales
The effect of type and location of baby cots on indoor environment quality in a daycare centre
Get PDFLittle children spend a lot of their time in daycare centres while their parents are at work. While the effect of poor indoor environmental quality (IEQ) in office buildings has been vastly studied, very limited empirical studies on the effect of different environmental factors in daycare centres is available. In this study, the indoor air quality within baby cots of a Dutch daycare centre was studied in detail. Besides an extensive literature survey, actual measurements were performed at a daycare centre especially the effects of type and location of baby cots on the perceived indoor environmental quality. Analysis of the results obtained from this study shows indoor air quality levels in daycare centres requires more attention. The intention of this research is to come forward with some guidelines based on the lessons learned
Development of the environmental observation scale for the indoor visual environment
No full textINTRODUCTION: Lighting and colors and contrast are known to have a positive effect on visual functioning of older adults. The highest estimated prevalence (±40%) of visual impairment in the Netherlands, has been found in nursing homes. An observation scale was developed to evaluate a healthy environment for the (visual impaired) nursing home resident. METHODOLOGIES: Based on the literature, environmental parameters of the Environmental Observation scale for the Visual Impaired (EOVI) were defined. In a two round Delphi study professionals determined the domains, and the items within these domains. RESULTS AND DISCUSSION: The domains of the scale are ‘illuminance’, ‘the use of color and contrast’ and ‘obstacles’. The scale evaluates common rooms of a nursing home ward and can be used to improve the environment. To reach content validity in total 27 items of the common rooms were judged by experts. Of common rooms 1 item was maintained, 16 were adjusted, 7 new items were added and three items were removed. CONCLUSION: The content validity for the domains and items was performed for the common rooms. To have a tool to evaluate visual performance conditions of nursing homes, the same procedure will be used for the corridors and bathrooms
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