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.
A firefighter is a first responder and rescuer extensively trained in firefighting, primarily to extinguish hazardous fires that threaten life, property, and the environment as well as to rescue people and in some cases or jurisdictions also animals from dangerous situations. Male firefighters are sometimes referred to as firemen.
A fire engine is a road vehicle that functions as a firefighting apparatus. The primary purposes of a fire engine include transporting firefighters and water to an incident as well as carrying equipment for firefighting operations. Fire trucks are big as School buses, Some fire engines have specialized functions, such as wildfire suppression and aircraft rescue and firefighting, and may also carry equipment for technical rescue.
A self-contained breathing apparatus (SCBA), sometimes referred to as a compressed air breathing apparatus (CABA) or simply breathing apparatus (BA), is a device worn to provide breathable air in an atmosphere that is immediately dangerous to life or health. They are typically used in firefighting and industry. The term self-contained means that the SCBA is not dependent on a remote supply of breathing gas. If designed for use under water, it is also known as a Scuba set. When not used underwater, they are sometimes called industrial breathing sets. Unofficial names include air pack, air tank, oxygen cylinder or simply pack, which are mostly used in firefighting.
A backdraft or backdraught is the abrupt burning of superheated gasses in a fire, caused when oxygen rapidly enters a hot, oxygen-depleted environment; for example, when a window or door to an enclosed space is opened or broken. Backdrafts present a serious threat to firefighters. There is some debate concerning whether backdrafts should be considered a type of flashover.
A flashover is the near-simultaneous ignition of most of the directly exposed combustible material in an enclosed area. When certain organic materials are heated, they undergo thermal decomposition and release flammable gases. Flashover occurs when the majority of the exposed surfaces in a space are heated to their autoignition temperature and emit flammable gases. Flashover normally occurs at 500 °C (932 °F) or 590 °C (1,100 °F) for ordinary combustibles and an incident heat flux at floor level of 20 kilowatts per square metre (2.5 hp/sq ft).
Ventilation is the intentional introduction of outdoor air into a space. Ventilation is mainly used to control indoor air quality by diluting and displacing indoor pollutants; it can also be used to control indoor temperature, humidity, and air motion to benefit thermal comfort, satisfaction with other aspects of indoor environment, or other objectives.
Firefighting is the act of attempting to prevent the spread of and extinguish significant unwanted fires in buildings, vehicles, and woodlands. A firefighter suppresses fires to protect lives, property and the environment.
Fire control is the practice of reducing the heat output of a fire, reducing the area over which the fire exists, or suppressing or extinguishing the fire by depriving it of fuel, oxygen, or heat. Fire prevention and control is the prevention, detection, and extinguishment of fires, including such secondary activities as research into the causes of fire, education of the public about fire hazards, and the maintenance and improvement of fire-fighting equipment.
Firefighting jargon includes a diverse lexicon of both common and idiosyncratic terms. One problem that exists in trying to create a list such as this is that much of the terminology used by a particular department is specifically defined in their particular standing operating procedures, such that two departments may have completely different terms for the same thing. For example, depending on whom one asks, a safety team may be referred to as a standby, a RIT or RIG or RIC, or a FAST. Furthermore, a department may change a definition within its SOP, such that one year it may be RIT, and the next RIG or RIC.
This is a glossary of firefighting equipment.
A pike pole is a long metal-topped wooden, aluminium or fiberglass pole used for reaching, hooking and/or pulling on another object. They are variously used in boating, construction, logging, rescue and recovery, power line maintenance, and firefighting.
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.
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.
The Charleston Sofa Super Store fire occurred on the evening of June 18, 2007, in Charleston, South Carolina and killed nine firefighters. This was the deadliest firefighter disaster in the US since the September 11 attacks. The fire was believed to have started in some discarded furniture in the loading dock area, and though the source of ignition remains undetermined, there is reason to believe it may have been a discarded cigarette.
One Meridian Plaza, formerly known as the Fidelity Mutual Life Building, Three Girard Plaza and Three Mellon Bank Center, was a 38-story high-rise office building in Philadelphia, Pennsylvania, United States. The 492-foot (150-meter) tower was designed by Vincent Kling & Associates and completed in 1972.
Firefighting is the act of extinguishing destructive fires. A firefighter fights these fires with the intent to prevent destruction of life, property and the environment. Firefighting is a highly technical profession, which requires years of training and education in order to become proficient. A fire can rapidly spread and endanger many lives; however, with modern firefighting techniques, catastrophe can usually be avoided. To help prevent fires from starting, a firefighter's duties include public education and conducting fire inspections. Because firefighters are often the first responders to victims in critical conditions, firefighters often also provide basic life support as emergency medical technicians or advanced life support as licensed paramedics. Firefighters make up one of the major emergency services, along with the emergency medical service, the police, and many others.
The use of a cutting extinguisher is a fire extinguishing technique that combines abrasive waterjet cutting with water spray extinguishing, through a single handpiece or nozzle. The fire-fighter approaches the fire from outside the main fire area, then uses the cutting action to drill a small hole through a door or wall. Switching to a water spray then allows the fire to be fought, as with a conventional fog nozzle.
Fire dampers are passive fire protection products used in heating, ventilation, and air conditioning (HVAC) ducts to prevent the spread of fire inside the ductwork through fire-resistance rated walls and floors. Fire/smoke dampers are similar to fire dampers in fire resistance rating, and also prevent the spread of smoke inside the ducts. When a rise in temperature occurs, the fire damper closes, usually activated by a thermal element which melts at temperatures higher than ambient but low enough to indicate the presence of a fire, allowing springs to close the damper blades. Fire dampers can also close following receipt of an electrical signal from a fire alarm system utilising detectors remote from the damper, indicating the sensing of heat or smoke in the building occupied spaces or in the HVAC duct system.
Cross-ventilation pertains to wind, fresh air or a breeze entering through an opening that flows directly through the occupied space and out through an opening on the opposite side of the building, where the air pressure is lower, whereby creating a flow of cool air and as well as a current of air across the room from the exposed area to the sheltered area. Windows or vents positioned on opposite sides of the room allow passive breezes a pathway through the structure, which circulate the air and provide passive cooling.
