Draft:Topic3: Thermal Comfort and Indoor Environmental Quality

1. Introduction-Julia

As ASHRAE guidelines stated , since people spend about 80–90% of their time indoors and studies have indicated that a range of comfort and health related effects are linked to characteristics of the building, there has been a growth in interest in both academic and practitioner literature on occupant health and building design. There are studies to suggest that a few symptoms of discomfort from indoor environment lead to significant reduction in work performance of occupants . New building regulations/legislations and green building guidelines have highlighted the past idea of sustainability that often ignored psychological, cultural and sociological dimensions . Human beings have endeavoured to create indoor environments in which they can feel comfortable. Human health is foremost when it comes to assessing the overall comfort of the environment. If for any reason the built environment is leading to sickness or negative impact on occupant health then it is a matter of concern and could point to some design or technical flaw in the building system.

1.1. Thermal comfort-Julia

Thermal comfort influenced by several factors, including:

• Air temperature
• Humidity
• Air velocity
• Mean radiant temperature
• Clothing insulation
• Metabolic rate

Thermal comfort involves maintaining a balance between the heat produced by the human body and the heat lost to the environment.

1.2. Indoor Environmental Quality (IEQ)

Indoor Environmental Quality (IEQ) is most simply described as the conditions inside the building. It includes air quality, but also access to daylight and views, pleasant acoustic conditions, and occupant control over lighting and thermal comfort. It may also include the functional aspects of space such as whether the layout provides easy access to tools and people when needed and whether there is sufficient space for occupants. Building managers and operators can increase the satisfaction of building occupants by considering all of the aspects of IEQ rather than narrowly focusing on temperature or air quality alone.

As ASHRAE guidelines stated , since people spend about 80–90% of their time indoors and studies have indicated that a range of comfort and health related effects are linked to characteristics of the building, there has been a growth in interest in both academic and practitioner literature on occupant health and building design. There are studies to suggest that a few symptoms of discomfort from indoor environment lead to significant reduction in work performance of occupants . New building regulations/legislations and green building guidelines have highlighted the past idea of sustainability that often ignored psychological, cultural and sociological dimensions . Human beings have endeavoured to create indoor environments in which they can feel comfortable. Human health is foremost when it comes to assessing the overall comfort of the environment. If for any reason the built environment is leading to sickness or negative impact on occupant health then it is a matter of concern and could point to some design or technical flaw in the building system.

So I am very interested in this topic, which is very relevant to my daily life, and the following content will revolve around this.

2.1. Key Components of Thermal Comfort --Zhang Fengguo

Thermal comfort refers to the condition of mind that expresses satisfaction with the thermal environment. It is a complex interplay of environmental, personal, and psychological factors. ANSI/ASHRAE Standard 55-2020, a globally recognized guideline, outlines the parameters necessary to ensure thermal comfort in indoor environments.

• Environmental Factors

The thermal environment significantly affects comfort through four primary variables:

1. Air Temperature: A key determinant of thermal comfort, it influences the body’s heat balance. For most people, temperatures between 20–26°C are considered comfortable.
2. Radiant Temperature: Surfaces that emit or absorb heat can alter perceptions of warmth. For instance, cold windows or warm walls can impact the overall thermal sensation.
3. Air Velocity: Proper airflow enhances heat dissipation, improving comfort, especially in warm conditions. However, drafts in cooler environments may cause discomfort.
4. Humidity: High humidity reduces sweat evaporation, leading to discomfort, while very low humidity can cause skin and respiratory dryness.

• Personal Factors

Personal characteristics, such as clothing insulation and metabolic rate, also play a vital role:

1. Clothing Insulation: Clothing provides thermal insulation, affecting heat exchange between the body and the environment. ANSI/ASHRAE 55 accounts for clothing insulation values (clounits) when assessing comfort.
2. Metabolic Rate: Higher activity levels generate more heat, requiring cooler environments for comfort. For instance, sitting (1.0 met) versus exercising (2.0 met) creates different thermal needs.

• Psychological and Contextual Factors

1. Psychological aspects, such as cultural expectations and prior experiences, also influence thermal comfort. For example, individuals accustomed to tropical climates may tolerate higher temperatures better than those from colder regions.

2.2. Key Components of IEQ-Julia

Indoor Environmental Quality (IEQ) encompasses several key elements that collectively impact the health, comfort, and productivity of building occupants. Here are the main components:

• Indoor Air Quality (IAQ)

1. Pollutants: Includes volatile organic compounds (VOCs), particulate matter, carbon dioxide (CO2), and other contaminants.
2. Ventilation: Proper ventilation helps to dilute and remove indoor pollutants.

• Thermal Comfort

1. emperature: Maintaining a comfortable temperature range is crucial.
2. Humidity: Balanced humidity levels prevent discomfort and health issues.

• Lighting

1. Natural Light: Access to daylight improves mood and productivity.
2. Artificial Lighting: Should be designed to minimize glare and mimic natural light.

• Acoustic Comfort

1. Noise Levels: Reducing unwanted noise and providing sound insulation enhances concentration and comfort.

• Ergonomics and Architecture.

1. Design: Ergonomic furniture and thoughtful architectural design support physical comfort and reduce strain.

• Access to Nature

1. Views and Greenery: Incorporating natural elements and views of nature can improve mental well-being.

3.1. Dynamic Integration, Optimization and Control-Julia

Because the conditions of a space are constantly changing based on the number, types and activities of occupants, these systems controlling indoor environmental quality need to be managed not just holistically — but also dynamically. The dynamic management of these systems allows for demand-based systems which use energy only when needed.

Digital technologies and connected solutions enable both near-real time optimization of energy, IEQ and hyper-personalization. By extending our analysis of IEQ from just systems into a specific space and even further to an individual occupant, hyper-personalized and optimized systems can lead to unprecedented improvements in energy efficiency. This can be accomplished by adding personal cooling, IAQ and lighting devices and integrating those devices into the broader system controls to optimize for personal comfort.artificial Intelligence for Efficient thermal Comfort.

3.2. Assess-Julia

Because every space is unique in its design, environment, and use, it is critical to assess the needs of that space first to determine the best approach to optimize IEQ for its occupants. In addition, as the use of the space evolves over time, ensuring that the proper indoor environment is supported may require recurring or continuous assessment techniques.

Assessments come in many forms and can address specific pieces of equipment, entire systems or even the application of those systems to the space and its need. Standards like LEED and other traditional approaches address how a system or space is designed but not how a space performs over time. Emerging methodologies and those recommended by the WELL Building Institute aim to address the issues associated with the performance of a space holistically.

In addition, there are several approaches and tools that can be applied to assess the indoor environmental quality of a space — ranging from simple measurement practices to assure minimum compliance with industry standards, to sophisticated modeling and simulation of airflow, lighting and acoustics in the space, and real-time surveys of occupants on various elements of IEQ. Solutions should therefore be tailored to the needs of the space, the occupants in that space and the needs of the customers who are charged with ensuring the right type of indoor environment is created to support its occupants.

3.3. Mitigate-Julia

Based on the outcomes of an assessment, mitigation strategies can be developed to eliminate issues with indoor environmental quality. In addition, micro-climates can be specifically designed to meet the needs of specific spaces by using occupant centric approaches. Since there are a great deal of options when it comes to mitigation and design strategies, it is critical to the select the right approach for the right situation.

It is that critical balance that differentiates us as a partner in the sustainable built environment. In fact, we have demonstrated that by focusing on use-centric strategies and optimizing systems around occupants, much greater energy savings can be achieved. We also focus on uncovering and maturing innovations that support the goal of reducing risk and improving energy efficiency simultaneously.

3.4. Manage-Julia

Since the purpose and use of any space can change over time, it is not sufficient to address indoor environmental issues just once. It is important to continue monitoring critical spaces and managing indoor environmental quality, ensuring that spaces always meet the needs of their occupants. Sensors and real time occupant surveys which provide feedback to automated control mechanisms enable real-time adjustments of indoor environments. Connected systems can enable remote experts to monitor and diagnose issues and recommend improvements based on sensors and system diagnostics, enabling a space to “react” to activities and incidents over time.

By continuously managing and monitoring spaces, we continue to ensure the best environments for occupants while optimizing energy usage, minimizing costs and carbon footprint. As digital and IoT (Internet of Things) technologies advance, our ability to control micro-climates, predict potential issues and improve the performance and environmental footprint of various spaces will also increase; enabling healthy and efficient spaces that endure over time.

4. Optimizing Thermal Comfort--Lin Zirui

Passive Design

• Using natural methods such as proper building orientation, shading, and insulation to reduce energy use.

1.Building orientation: Choose the right building orientation based on local climate and sun trajectory to maximize solar gain and reduce direct sunlight when necessary. Place windows on the south or west side of the building to gain solar heating in winter and reduce heat gain through shading measures in summer.

2.Shading design: Use fixed shading facilities such as blinds, sunshades or roof overhangs to block direct sunlight and reduce indoor temperatures. Use adjustable shading facilities such as electric curtains, blinds or awnings to adapt to different weather conditions.

3.Insulation: Use high-efficiency insulation materials such as aerogels, phase change materials or vacuum insulation panels and insulation technology to improve the insulation performance of the building envelope and reduce heat transfer.

4.Natural ventilation: Use the wind pressure difference generated by openings in different parts of the building, such as windows or doors, to promote air flow. Similarly, the thermal pressure difference generated by the temperature difference between indoor and outdoor can be used to promote air flow.

Active Systems

• Advanced HVAC systems and smart technologies for temperature regulation.

1.Intelligent HVAC system: Adopting the intelligent building energy-saving thermal comfort control framework based on deep reinforcement learning, by predicting and optimizing the operation strategy of the HVAC system, the prediction accuracy of thermal comfort is improved, and the purpose of reducing energy consumption is achieved at the same time.

2.Multi-objective optimization control: Considering the two objective functions of indoor thermal comfort and energy consumption, the genetic algorithm is used to optimize the HVAC system parameters to achieve energy efficiency optimization.

3.Dynamic thermal comfort control: Based on the particle swarm optimization algorithm, the thermal environment and the thermal perception data of the occupants to the environment are measured in real time to achieve the optimal control of dynamic comfort.

Energy-Efficient Strategies

• Integration of renewable energy sources and systems that minimize environmental impact.

1.Renewable energy integration: Solar panels, wind turbines and geothermal systems can provide sustainable energy for buildings. The integration of multiple renewable energy sources can be achieved by coupling wind and solar power generation with hydrogen energy storage systems. Through technologies such as water electrolysis, hydrogen storage and hydrogen fuel cells, the large-scale application of renewable energy-hydrogen-electricity can be achieved.

2.Integrated Energy System (IES): By integrating multiple energy resources, the energy production, supply, storage and consumption processes are optimized to improve energy efficiency and reduce environmental pollution. These systems usually include photovoltaics, wind power, cogeneration, gas boilers, electric boilers, electric energy storage and carbon capture equipment. Optimization scheduling methods include stochastic programming, robust optimization, long-term optimization, medium- and short-term optimization and real-time scheduling. These methods can cope with the uncertainty of renewable energy and the fluctuation of load demand.

5. Health and Well-being Impact

Discuss the connection between thermal comfort, health, and productivity. Poor thermal conditions can lead to discomfort, reduced efficiency, and health issues.

6. Challenges and Future Trends

Balancing energy efficiency with individual comfort preferences.

Innovations in building materials and smart systems aimed at improving thermal comfort and IEQ.

7.Conclusion

Summarize the importance of addressing thermal comfort and IEQ in building design for enhanced occupant satisfaction and well-being.

Encourage the integration of sustainable practices in building development.