Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. "Refrigeration" is sometimes added to the field's abbreviation as HVAC&R or HVACR, or "ventilation" is dropped, as in HACR.
Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the same techniques used to excavate ores of gems, such as diamonds and rubies. Soft-rock mining refers to the excavation of softer minerals, such as salt, coal, and oil sands.
An adit or stulm is a horizontal or nearly horizontal passage to an underground mine. Miners can use adits for access, drainage, ventilation, and extracting minerals at the lowest convenient level. Adits are also used to explore for mineral veins.
In architecture, a clerestory is a high section of wall that contains windows above eye-level. Its purpose is to admit light, fresh air, or both.
A solar chimney – often referred to as a thermal chimney – is a way of improving the natural ventilation of buildings by using convection of air heated by passive solar energy. A simple description of a solar chimney is that of a vertical shaft utilizing solar energy to enhance the natural stack ventilation through a building.
In architecture, an atrium is a large open-air or skylight-covered space surrounded by a building. Atria were a common feature in Ancient Roman dwellings, providing light and ventilation to the interior. Modern atria, as developed in the late 19th and 20th centuries, are often several stories high, with a glazed roof or large windows, and often located immediately beyond a building's main entrance doors.
A windcatcher, wind tower, or wind scoop is a traditional architectural element, originated in Iran (Persia), used to create cross ventilation and passive cooling in buildings. Windcatchers come in various designs, depending on whether local prevailing winds are unidirectional, bidirectional, or multidirectional, on how they change with altitude, on the daily temperature cycle, on humidity, and on how much dust needs to be removed. Despite the name, windcatchers can also function without wind.
Shaft mining or shaft sinking is the action of excavating a mine shaft from the top down, where there is initially no access to the bottom. Shallow shafts, typically sunk for civil engineering projects, differ greatly in execution method from deep shafts, typically sunk for mining projects.
Ventilation is a part of structural firefighting tactics, and involves the expulsion of heat and smoke from a burning building, permitting the firefighters to more easily and safely find trapped individuals and attack the fire. If a large fire is not properly ventilated, it is much harder to fight, and can build up enough poorly burned smoke to create a smoke explosion or enough heat to create a flashover. Poorly placed or timed ventilation can increase the fire's air supply, causing it to grow and spread rapidly. Flashover from inadequate ventilation can cause the temperature inside the building to peak at over 1,000 °C (1,830 °F).
The stack effect or chimney effect is the movement of air into and out of buildings through unsealed openings, chimneys, flue-gas stacks, or other containers, resulting from air buoyancy. Buoyancy occurs due to a difference in indoor-to-outdoor air density resulting from temperature and moisture differences. The result is either a positive or negative buoyancy force. The greater the thermal difference and the height of the structure, the greater the buoyancy force, and thus the stack effect. The stack effect helps drive natural ventilation, air infiltration, and fires.
In architecture, a lightwell, sky-well, or air shaft is an unroofed or roofed external space provided within the volume of a large building to allow light and air to reach what would otherwise be a dark or unventilated area. Lightwells may be lined with glazed bricks to increase the reflection of sunlight within the space. Lightwells may have sunlight reflecting mirrors on the top of light well.
Passive cooling is a building design approach that focuses on heat gain control and heat dissipation in a building in order to improve the indoor thermal comfort with low or no energy consumption. This approach works either by preventing heat from entering the interior or by removing heat from the building.
Passive ventilation is the process of supplying air to and removing air from an indoor space without using mechanical systems. It refers to the flow of external air to an indoor space as a result of pressure differences arising from natural forces.
In architecture, an area is an excavated, subterranean space around the walls of a building, designed to admit light into a basement. Also called a lightwell, it often provides access to the house and a store-room/service cupboard for tradesmen, such as a coal store vault under the pavement.
Old Law Tenements are tenements built in New York City after the Tenement House Act of 1879 and before the New York State Tenement House Act of 1901. The 1879 law required that every habitable room have a window opening to plain air, a requirement that was met by including air shafts between adjacent buildings. Old Law Tenements are commonly called "dumbbell tenements" after the shape of the building footprint: the air shaft gives each tenement the narrow-waisted shape of a dumbbell, wide facing the street and backyard, narrowed in between to create the air corridor. They were built in great numbers to accommodate waves of immigrating Europeans. The side streets of Manhattan's Lower East Side are still lined with numerous dumbbell structures today.
Underground mine ventilation provides a flow of air to the underground workings of a mine of sufficient volume to dilute and remove dust and noxious gases (typically NOx, SO2, methane, CO2 and CO) and to regulate temperature. The source of these gases are equipment that runs on diesel engines, blasting with explosives, and the orebody itself.
Ventilation may refer to:
The Tower at PNC Plaza is a 33-story skyscraper in Pittsburgh, Pennsylvania. It is the corporate headquarters of the PNC Financial Services Group and has approximately 800,000 square feet (74,000 m2), standing 33 stories tall. Nearby buildings totaling 37,000 square feet (3,400 m2), were purchased by PNC and deconstructed to make space for the Tower at PNC Plaza. It is located at the intersection of Fifth Avenue and Wood Street, where PNC and its predecessors have been based since 1858.
Oasia Hotel Downtown is a 27-story mixed-use hotel and office skyscraper in the Downtown Core district of Singapore. Its exterior includes 21 species of climbing plants on its facade. The building's exterior, constructed atop vertical grid panels, will appear more "furry" over time, with only specks of its orange, pink and maroon aluminium mesh exterior remaining visible. About 40 percent of the building's volume consists of communal green space elevated vertically into the skyscraper.
