Құрылыс қаптамасы: қасиеттері мен мақсаты

Concept in architectural and engineering practice
A building envelope or building enclosure is the physical separator between the conditioned and unconditioned environment of a building, including the resistance to air, water, heat, light, and noise transfer.

Control of airflow is important to ensure indoor air quality, control energy consumption, avoid condensation (and thus help ensure durability), and to provide comfort. Control of air movement includes flow through the enclosure (the assembly of materials that perform this function is termed the air barrier system) or through components of the building envelope (interstitial) itself, as well as into and out of the interior space, (which can affect building insulation performance greatly). Hence, air control includes the control of windwashing (cold air passing through insulation) and convective loops which are air movements within a wall or ceiling that may result in 10% to 20% of the heat loss alone. The physical components of the envelope include the foundation, roof, walls, doors, windows, ceiling, and their related barriers and insulation. The dimensions, performance and compatibility of materials, fabrication process and details, connections and interactions are the main factors that determine the effectiveness and durability of the building enclosure system. Common measures of the effectiveness of a building envelope include physical protection from weather and climate (comfort), indoor air quality (hygiene and public health), durability and energy efficiency. In order to achieve these objectives, all building enclosure systems must include a solid structure, a drainage plane, an air barrier, a thermal barrier, and may include a vapor barrier. Moisture control (e. g. damp proofing) is essential in all climates, but cold climates and hot humid climates are especially demanding. Air sealing can improve the energy efficiency of a building by minimizing the amount of energy needed to heat or cool the building. This is especially pertinent in cold climate buildings where space heating consumes the largest amount of energy. A blower door test can be used to test the quality of the air sealing of the building envelope. Smoke pencils can be used to detect gaps and caulking and weather stripping can be used to improve air sealing. HVAC systems can ensure that a building’s air intake is both adequate, safe, and energy efficient.

The thermal envelope, or heat flow control layer, is part of a building envelope but may be in a different location such as in a ceiling. The difference can be illustrated by the fact that an insulated attic floor is the primary thermal control layer between the inside of the house and the exterior while the entire roof (from the surface of the roofing material to the interior paint finish on the ceiling) is part of the building envelope. Building envelope thermography involves using an infrared camera to view temperature anomalies on the interior and exterior surfaces of the structure. Analysis of infrared images can be useful in identifying moisture issues from water intrusion, or interstitial condensation. Other types of anomalies that can be detected are thermal bridging, continuity of insulation and air leakage, however this requires a temperature differential between the inside and outside ambient temperatures.