• building energy saving
• local cooling
• local heating
• personal comfort system (PCS)

Addressing the well-being and comfort of individuals has emerged as a central concern for researchers. The assessment of the thermal environment holds particular significance, given its substantial impact on both the comfort of occupants and the energy efficiency of the building. Thermal comfort is the most influential Indoor Environmental Quality (IEQ) factor in space perception and the predominant on energy consumption.
Ensuring thermal comfort holds utmost significance in work environments, playing a dual role in enhancing personal well-being and boosting productivity while also being a primary contributor to overall dissatisfaction within a space. The widespread adoption of remote work following the COVID-19 pandemic has left numerous offices understaffed. This shift has directly translated into inefficient energy usage, resulting in increased energy consumption in domestic settings and the unnecessary air-conditioning of entire offices, even when a significant number of desks remain unoccupied.
In this context, numerous researchers have developed models and systems designed to meet individual needs, such as Personal Comfort Systems (PCSs). PCSs are defined as systems that heat and cool individuals without affecting the surrounding environments and other occupants. Unlike traditional HVAC systems that condition the entire building volume, PCSs focus solely on creating a "personal" microclimate. This targeted approach allows for the customization of thermal conditions at individual workstations, enabling the primary HVAC system to operate within a broader setpoint range and leading to a significant reduction in overall energy consumption. Despite these advantages, the technological solutions for implementing PCSs are still under research, and the current market offers a limited selection of PCS options.
This comprehensive research delves into the exploration of PCSs in building environments, focusing on heating and cooling conditions for flexible office setups.
The thesis begins with an overview of thermal comfort, encompassing evaluation procedures, standards, and models for assessing both temperature and sensation indices, as well as addressing the causes of local discomfort. A critical review of current PCSs follows, highlighting their historical evolution, challenges, and potential benefits. The study emphasizes the shift from conditioning entire spaces to treating individual areas, optimizing energy use, and improving perceived thermal comfort, especially in the context of the COVID-19 pandemic and remote working trends.
The research advances into a case study of office buildings, exploring global and local comfort and discomfort in different landscape offices. The findings reveal suboptimal conditions in modern offices, emphasizing the potential of PCSs in creating more sustainable and occupant-centric workspaces.
A preliminary study and sizing of a new PCS, specifically a heating desk, are conducted using Building Energy Simulation (BES) and Computational Fluid Dynamics (CFD). The results indicate substantial energy savings and improved localized thermal comfort, laying the foundation for further analyses and real-world prototyping.
Therefore, the first experimental phase focuses on prototyping and studying different versions of heated desks, exploring innovative solutions. The PCS was able to recreate a neutral comfort environment at 17°C ambient dry-bulb temperature heating efficiently hands by conduction and thighs, ankles, and face by radiation. Then, the research highlights advancements in ergonomic design and reduced energy consumption, showcasing also the potential for energy-saving benefits.
Moving forward to the cooling side, the study explores an uncharted PCS – the Evaporative Cooler Fan (ECF) – as a sustainable solution for cooling and reducing heat strain risk during heatwaves. Results demonstrate promising temperature reductions, effective humidity control, and high Corrective Power (CP) values on experimental activities, positioning ECF as a cost-effective PCS alternative to traditional air conditioning.
The research concludes with a BES analysis of the previously studied PCSs in various scenarios, focusing on a standard three-floor office building under diverse climatic conditions. The evaluation method considers factors such as energy cost, CO2 emissions, and primary energy consumption, providing insights into the year-round adaptability, efficacy, and efficiency of PCSs, with energy savings up to 50% with the heating desk and 65% with the ECF.
The findings advocate for tailored approaches based on climate and building characteristics, envisioning a future where innovative technologies, user-centric design, and sustainable solutions drive a paradigm shift in applying PCSs for enhanced comfort, energy efficiency, and reduced carbon footprint in building environments.