Detection of Air Leakage in Building Envelopes using Microphone Arrays

Unintended airflow through building envelopes leads to an increased demand in heating and cooling energy. The most common way to measure air leakage of buildings is the blower door test, which quantifies the overall leakage rate of one room or a building. To reduce air leakage and associated energy loss in new and existing buildings, it is necessary to identify leak locations and prioritize sealing of more substantial leaks.

Design of a Retrospective Survey for Occupant Satisfaction with IEQ in Classrooms

The occupants’ satisfaction with the indoor environmental quality (IEQ) of a building is a key factor to determine if the indoor climate can be considered as acceptable. Current standards, evaluating the IEQ, do not always guarantee sufficiently high occupant satisfaction levels, since these standards do not handle all satisfaction influencing parameters, such as, personal preferences or perceived control. Therefore, the assessment of occupant satisfaction with the IEQ remains an important issue.

Developing a New Passive Tracer Gas Test for Air Change Rate Measurement

This paper describes the ongoing development of a new tracer gas test (TGT) for total air change rates measurement. This new TGT, intended for use in large-scale IAQ assessments and based on constant tracer injection, employs an alternative tracer gas that is more adequate than the currently employed SF6 and perfluorocarbons and that can be co-captured and co-analyzed along with commonly assessed VOCs using a commercial passive IAQ sampler. Via literature study and lab testing, decane-D22 was found to be a suitable tracer substance.

Development of a Smart Thermostat

Recently, understanding thermal comfort management enabled the scientific community to broaden its research towards smart device set-ups, in order to further reduce energy consumption and thermal comfort satisfaction. Thus, the need to minimize user interaction and implement prediction functions has arisen. In this work, the development of a smart thermostat is presented. The procedure is divided into three basic stages: calibration, development of energy saving and thermal comfort routines, and comparison with a conventional thermostat’s operation.

Ventilation Benefits when Using Radiative Cooling Material in High Ambient Temperature Countries

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.

Development of Performance-Based Assessment Methods for Conventional and Smart Ventilation in Residential Buildings

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.

Do Spatially Distributed Sensor Measurements Provide Better Representation of Indoor Environment than Single Sensor Measurements? A Mechanically Ventilated Office Space Case Study

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.

Effect on Thermal Comfort and Energy Consumption of Different Installation Height and Supply Air Angle of Room Air Conditioner by Simulation

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.

Examination of Occupant Arrangement in an Office Floor based on Nonuniformity of CO2 Concentration Using Computational Fluid Dynamics (CFD) Simulation

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.

Experimental Study of Cool Roof Impact on Building Performance in Hot-Dry and Dusty Climates

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.