Internal Environment of Buildings PDF

School of Architecture & the Built Environment **MECHANICAL SERVICES BE6812** 4. **[Internal Environment of Buildings]** Objectives: This topic provides an overview of the building's indoor (or internal) environment. It covers the need for a pleasant environment, the factors that would likely af...

School of Architecture & the Built Environment **MECHANICAL SERVICES BE6812** 4. **[Internal Environment of Buildings]** Objectives: This topic provides an overview of the building's indoor (or internal) environment. It covers the need for a pleasant environment, the factors that would likely affect the pleasantness of the indoor environment and the instruments that are used to measure these factors. **4.1 [Necessity of a Pleasant Indoor Environment]** Buildings provide an environment for the occupants to perform a desired task. We spend most of our time indoor working, relaxing or simply resting. The indoor environment should therefore, be as pleasant and comfortable as possible. The indoor environment comprises the physical space itself, it also include another factor called the ***indoor climate.*** This indoor climate includes: - the air quality ( ventilation and air movement ) - the thermal conditions ( temperature and relative humidity ) - the acoustic condition (sound level) - the lighting condition (both quality and quantity) The indoor environment (especially for buildings that are not totally enclosed, i.e. naturally ventilated buildings) are affected to a certain extent by the quality of the external environment, i.e. the type of climate and quality of the outdoor air. However, if due considerations are given at the design stage to the building layout, use of building materials and the incorporation of mechanical and electrical services, the indoor environment in any building can be made as pleasant as possible to the occupants. A good indoor environment enhances:- - occupant's health. - occupant's comfort. - deterioration of occupant's health. - less satisfied tenant (in a rental property) - creating negative publicity Failure to respond promptly and effectively to indoor environmental problems can lead to :- - deterioration of the furnishing (eg. carpet, curtain, etc). - deterioration of the equipment. - deterioration of occupant's health; - less satisfied tenant (in a rental property); - creating negative publicity To achieve a healthy indoor environment, the building will need to operate in an environmentally conscious manner throughout the building's life cycle, i.e. from the initial design to the construction, occupancy and maintenance of a building. **4.2 UN SDG 3: Good Health and Well-Being** UN SDG Goal 3 aims to ensure healthy lives and promote well-being for all at all ages. This goal encompasses reducing mortality rates, combating diseases, promoting mental health, and improving health systems [The Importance of Indoor Environments] People spend around 90% of their time indoors, making the quality of these environments critical to overall health. Poor indoor conditions can lead to respiratory problems, increased stress levels, and reduced productivity. A well-maintained indoor environment can significantly impact physical and mental health by ensuring good air quality, adequate lighting, comfortable temperature, and noise control. By addressing these factors, buildings can help reduce the risk of respiratory issues, stress, and other health problems, thereby promoting overall well-being. Poor indoor air quality, often caused by pollutants like mold, dust, and chemicals, can lead to respiratory issues and other health problems. Adequate lighting, comfortable temperature, and humidity levels are essential for physical comfort and mental well-being. Additionally, minimizing noise pollution can reduce stress and improve sleep quality. Ensuring a healthy indoor environment involves regular maintenance, proper ventilation, and the use of non-toxic materials. - **Indoor Air Quality**: Poor indoor air quality can lead to various health issues, including respiratory problems, allergies, and even cardiovascular diseases. Sustainable buildings focus on improving ventilation, reducing indoor pollutants, and using non-toxic materials to enhance air quality. - **Natural Lighting and Ventilation**: Access to natural light and proper ventilation can significantly impact mental and physical health. Buildings designed with ample natural light and good airflow can reduce stress, improve mood, and enhance overall well-being. - **Thermal Comfort**: Maintaining a comfortable indoor temperature is crucial for health and productivity. Sustainable buildings often incorporate energy-efficient heating and cooling systems to ensure a stable and comfortable indoor climate. - **Noise Reduction**: Excessive noise can lead to stress, sleep disturbances, and other health issues. Sustainable building designs often include soundproofing measures to create a quieter and more peaceful indoor environment. - **Access to Clean Water**: Ensuring access to clean and safe water within buildings is essential for health. Sustainable buildings often incorporate water purification systems and efficient water management practices. By addressing these aspects, sustainable buildings contribute to achieving SDG 3 by creating healthier indoor environments that promote the well-being of occupants. **4.3 [Factors Affecting the Indoor Climate]** \(a) [Ventilation] Ventilation is the process of providing \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ and the \_\_\_\_\_\_\_\_\_\_\_\_ of stale air from a building. The amount of ventilation depends on the indoor air movement and the air change rate. Ventilation is required to maintain good \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. \(b) [Thermal Condition] The human body needs to lose heat to the surrounding environment in order to keep the body at a constant temperature. The rate of heat loss will depend on the \_\_\_\_\_\_\_\_\_\_\_\_ and the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ of the surrounding air. \(c) [Acoustic Condition] Excessive exposure to high sound levels in an indoor environment may affect the occupants of a building. \(d) [Lighting Condition] Indoor lighting comes from both natural daylight and artificial lighting. Poor quality of light may produce colour distortion. Excessive or insufficient lighting levels may result in \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ and \_\_\_\_\_\_\_\_\_\_\_\_\_\_. **4.4 [Instruments Used to Determine These Factors]** +-----------------+-----------------+-----------------+-----------------+ | S/No. | Factor | Unit | Instrument | +=================+=================+=================+=================+ | 1. | Air Movement. | m/s |  | | | air flow in a | | | | | room. It helps | | imagesCAS41N58 | | | to increase the | | | | | heat loss from | | | | | the body by | | | | | convection.* | | | +-----------------+-----------------+-----------------+-----------------+ | 2. | Air | °C |  | | | *The air | | | | | temperature | | | | | refers to the | | | | | average | | | | | temperature of | | | | | the air inside | | | | | a room.* | | | +-----------------+-----------------+-----------------+-----------------+ | 3. | Mean Radiant | °C | Description: | | | Temperature | | globe | | | (MRT) | | thermometer.jpg | | | | | | | | *The MRT is the | | | | | average effect | | | | | of radiation | | | | | from the | | | | | surrounding | | | | | surfaces inside | | | | | a room.* | | | +-----------------+-----------------+-----------------+-----------------+ | 4. | Relative | \% |  | | | *The RH of a | | | | | sample of air | | | | | is the ratio of | | | | | the actual | | | | | amount of | | | | | moisture in the | | | | | air compared to | | | | | the maximum | | | | | amount of | | | | | moisture the | | | | | air can hold at | | | | | that | | | | | temperature.* | | | +-----------------+-----------------+-----------------+-----------------+ | 5. | Sound Level | Decibel (dB) | slm2 | | | | | | | | *Sound is the | | | | | pressure | | | | | variation in a | | | | | medium and is | | | | | measured by the | | | | | Sound Pressure | | | | | Level (SPL)* | | | +-----------------+-----------------+-----------------+-----------------+ | 6. | Lighting Level | lux (lx) |  | | | *It is | | | | | determined by | | | | | measuring the | | | | | illumination | | | | | level.* | | | +-----------------+-----------------+-----------------+-----------------+