Thermal comfort, IAQ and Energy use in Bedrooms

The research question of this report is “Is it possible to save energy by lowering the bedroom temperatures in winter”. In this paper first the literature on optimum sleeping temperatures is investigated. Then bedroom temperatures and CO2 levels in a cold week in March 2018 are investigated in 16 bedrooms of students of the Master course Technoledge Climate Desing in 2017-2018 of the faculty of Architecture and the Built Environment of the Delft University of Technology. This study shows that it must be possible to save energy by lowering the bedroom temperature in winter.

Survey on the thermal comfort and occupant behaviour in the bedrooms of Japanese houses

In order to know the thermal comfort of bedrooms, we have measured the air temperature and relative humidity in the 27 bedrooms of 11 houses. We have also conducted a thermal comfort survey, quality of sleep and occupant behaviour survey with the residents. Residents are highly satisfied with the thermal condition of the houses, using various thermal adjustments such as fans, clothing modifications, etc.

Effects of window position on the air flow distribution in a cross-ventilated residential bedroom.

Results of an investigation of the effects of window position on the airflow characteristics for a typical bedroom setting in Taiwan are presented. Four different window positions were examined in the experiment which used a full-scale laboratory bedroom model with a single bed. A three-dimensional ultrasonic anemometer was used to measure airflow distribution and the results of flow measurements at two height levels are presented. Computer simulation of the airflow distribution was performed using the standard k-e turbulence model.

A study of a control strategy utilizing outdoor air to reduce the wintertime carbon dioxide levels in a typical Taiwanese bedroom.

A C02 concentration of more than 1000 ppm has been monitored in Taiwanese bedrooms during sleeping hours in the wintertime. The high indoor C02 levels were caused by poor ventilation due to insufficient ventilation rates. This study sought to reduce the wintertime C02 concentration level in a typical Taiwanese bedroom with less outdoor air to maintain thermal comfort. C02 was used as an indicator to assess whether an adequate ventilation rate has been obtained to dilute or remove harmful pollutants.

The Southampton survey on asthma and ventilation: humidity measurements during winter.

As part of a collaborative trial on the effects of ventilation on house dust mites and asthma, 20 mechanical ventilation units were installed in houses in the Southampton area in southern England. The hypothesis is that continuous ventilation over winter months can maintain humidity below a mixing ratio of 7 g/kg, with a consequent reduction in house dust mite numbers. The systems served upstairs only, extracting from bathroom and landing and supplying fresh air to bedrooms.