• Energy Research

Office employees often face discomfort due to dry air, impacting their productivity. Existing solutions like standalone humidifiers or HVAC-integrated systems are either inefficient or costly. Thus, maintaining optimal air humidity remains a challenge. Green walls offer a potential solution by influencing humidity and air quality. A survey was conducted in five Warsaw office buildings involving 85 participants to investigate this issue. Measurements were taken in three stages: without humidifiers, with standalone humidifiers, and with green walls. The results showed a high acceptance of humidification systems, with green walls being perceived as the most effective in neutralizing air humidity perception. The air quality was rated highest with both humidifiers and green walls. Notably, well-being indicators significantly improved with humidifiers, particularly with the presence of green walls. This study underscores the potential of green walls in improving indoor environmental conditions and occupants’ well-being, offering a promising avenue for enhancing office comfort and efficiency.

Reduction of the primary energy consumption is a crucial challenge for the building sector due to economic and environmental issues. Substantial savings could be achieved within the household. In this paper, we investigate the energy performance of a single-family house located in the temperate climate. The assessment is based on the comprehensive thermal diagnostic of the building performed on-site and via computational analyses. The on-site measurements included diagnostics of the building envelope, heat source, heating and domestic hot water system, ventilation system, and indoor environmental quality. Analyses confirmed that the studied building, which was built in 2008, meets the legislation requirements for the primary energy usage at that time and nowadays. However, results show discrepancies between energy performance obtained through on-site measurements and computational methods following regulations. Partially, discrepancies are a result of differences on normative values and how the building is operated in practice. It is also showed how important the role in the assessment of energy consumption through measurements is played by the measurement period.

The energy consumption of purely convective (i.e., various air volume (VAV) mixing ventilation) and combined radiant and convective HVAC systems (chilled ceiling combined with mixing ventilation—CCMV or personalized ventilation—CCPV) was investigated with multi-variant simulations carried out the IDA Indoor Climate and Energy software. We analyzed three different climates: temperate, hot and humid, and hot and dry. Our results show that the use of CCPV substantially reduced energy consumption compared to the conventional VAV system in hot climates. We also show that increasing the room temperature to 28 °C is an effective energy-saving strategy that can reduce consumption by as much as 40%. In the temperate climate, the VAV system was preferable because it used less energy as it benefited from outdoor air free-cooling. The control strategy of the supply temperature of personalized air had an impact on the energy demand of the HVAC system. The most efficient control strategy of the CCPV system was to increase the room temperature and keep the supply air temperature in the range of 20–22 °C. This approach consumed less energy than VAV or CCMV, and also improved the relative humidity in the hot climate.

AbstractThis paper introduces a database of 34 field-measured building occupant behavior datasets collected from 15 countries and 39 institutions across 10 climatic zones covering various building types in both commercial and residential sectors. This is a comprehensive global database about building occupant behavior. The database includes occupancy patterns (i.e., presence and people count) and occupant behaviors (i.e., interactions with devices, equipment, and technical systems in buildings). Brick schema models were developed to represent sensor and room metadata information. The database is publicly available, and a website was created for the public to access, query, and download specific datasets or the whole database interactively. The database can help to advance the knowledge and understanding of realistic occupancy patterns and human-building interactions with building systems (e.g., light switching, set-point changes on thermostats, fans on/off, etc.) and envelopes (e.g., window opening/closing). With these more realistic inputs of occupants’ schedules and their interactions with buildings and systems, building designers, energy modelers, and consultants can improve the accuracy of building energy simulation and building load forecasting.