English

Cooling in high ambient temperature (HAT) countries is a major energy consumer. In Kuwait, 70% of the electricity generated is consumed on cooling residential and commercial buildings. Because of the extreme temperatures in the summer, which can reach 50℃, outdoor fresh air vents are closed because AC units are incapable of cooling air at such elevated temperatures. Consequently, this has significantly reduced indoor air quality (IAQ) in residential and commercial buildings for indoor occupants.

In future building regulations, building performance is going to be extended to global performance, including indoor air quality (IAQ). In the energy performance (EP) field, successive regulations pushed for a "performance-based" approach, based on an energy consumption requirement at the design stage. Nevertheless, ventilation regulations throughout the world are still mostly based on prescriptive approaches, setting airflows requirements.

Most existing office buildings are equipped with indoor environmental quality (IEQ) sensors that are connected to the Building Management System (BMS) and provide feedback to the heating, ventilation and air-conditioning (HVAC). Unfortunately, they are often installed in locations selected based on practical reasons rather than for reliable representation of IEQ at actual workplaces. This leads to a difference in the IEQ sensed by the BMS and the occupants, resulting in increased complaints and decreased occupant satisfaction.

Improving actual operation performance of room air conditioners (RAC) shows great importance in the indoor environment and building energy conversation. The installation height and supply air angle of the indoor unit of RAC directly affect thermal comfort and energy performance in heating conditions. In this paper, a combined simulation of building, indoor air distribution, and performance of RAC is proposed to investigate the influence of installation height and supply air angle. The combined simulation model was validated by experiment results.

Heating, ventilating, and air conditioning (HVAC) systems attempt to achieve a uniform indoor environment. However, this can be challenging, because the placement and control of HVAC systems and sensors are affected by many unpredictable factors. The efficacious exploitation of this nonuniformity can lead to an improvement of indoor environment around occupants. Of the many indoor environment variables, we focused on the CO2 concentration associated with ventilation.

Maintaining thermal comfort in buildings has become a big challenge in developing countries. Cool roof or high reflective/emissive roof reduces absorbed building solar energy, roof surface temperature to reduce energy consumption and maintain thermal comfort. However, the impact on buildings thermal performance located in hot-dry climate and dusty conditions is not well-known.

For an ideal building airtightness test, the pressure difference between inside and outside would be constant over time and uniform along the entire building envelope, so that each leakage is equally considered and that the test result does not depend on the test conditions. This is particularly challenging for high-rise buildings as they are more subject to strong stack effects: the temperature difference between inside and outside induces a pressure difference along the envelope directly proportional to its height.

Indoor air quality (IAQ) control in educative centres, where students spend most of their time, is essential. The presence of high levels of contaminants can impact the academic performance of the students and, ultimately, their health. A study has been carried out to assess the IAQ of higher education classrooms with natural ventilation in order to quantify the exposure of the occupants to certain contaminants during the cold season. CO2, PM10, PM2.5, PM1.0, and volatile organic compounds (VOC) have been measured.

How accurately can reduced-order dynamic building energy simulation models (with Dymola simulation software) simulate the indoor climate (i.e., indoor air temperature, relative humidity and CO2-concentration) in common inhabited residential buildings? In order to address this question, high resolution measurement data of a zero-energy case study dwelling were gathered through a measurement campaign. A dynamic multi-zone modelling approach has been applied to have room-level indoor climate results.

In this paper various direct reading instruments and techniques used in air monitoring are reviewed. Principles of operation are described, pointing out advantages and disadvantages of using such instruments. A procedure for inspection activities, and a sampling and analysis approach is outlined. One case study, covering inspection in an office space is presented in detail, describing monitoring of different types of contaminants, possible false positives and calculations related to exposure limits.