Information & explanations, latest texts & monographs on
HVAC (including recent related patents.)
HVACHVAC is an initialism that stands for "heating, ventilation, and air-conditioning". This is sometimes referred to as climate control. These three functions are closely interrelated, as they all change the temperature, pressure and humidity of the air within the building. In modern building designs, the design, installation and control systems of these functions are integrated into a single "HVAC" system. Table of contents showTocToggle("show","hide") 1 Heating 1.1 Central Heating 1.2 Local Heating 2 Ventilation 2.1 Natural Ventilation 2.2 Forced Ventilation 3 Air-Conditioning 4 Thermostats 5 External links Heating Heating systems may be classified as central or local. Central Heating Central heating is often used in cold climates to heat private houses and public buildings. Such a system contains a central boiler, furnace or heat pump to heat water, pipework to distribute the heated water, and heat exchangers or radiators to conduct this heat to the air. The term radiator in this context is misleading, since most heat transfer from the heat exchanger is by convection, not radiation. The heat exchangers may be mounted on walls, or buried in the floor to give under-floor heating. When so mounted it is often referred to as "radiant heating". All but the simplest systems have a pump to circulate the water and ensure an equal supply of heat to all the radiators. The heated water is often fed through another heat exchanger inside a storage cylinder to provide hot running water. Forced air systems send air through ductwork. The ductwork can be reused for air conditioning and the air can be filtered or put through air cleaners. The heating elements (radiators or vents) should be located in the coldest part of the room, typically next to the windows. Popular retail devices that direct vents away from windows to prevent "wasted" heat defeat this design parameter. Drafts contribute more to the subjective feeling of coldness than actual room temperature. Thus rather than improving the heating of a room/building, it is often more important to control the air leaks. The invention of central heating is often credited to the ancient Romans, who installed a system of air ducts in walls and floors of public baths and private villas. The ducts were fed with hot air from a central fire. Perhaps there are examples from other early civilisations waiting to be unearthed. Local Heating Local heating devices are self-contained heaters that are usually controlled manually. Such devices include:
This article is adapted from from Wikipedia All Wikipedia article text is available under the terms of the GNU Free Documentation License Recent HVAC related patents From USPTO: 6718240: Remote keyless entry system 6718100: Fire resistant conduit insert for optical fiber cable 6717919: Imprinting method for automated registration and configuration of network devices 6717654: Combined range-finding, sighting and scanning system and method 6717524: Voice acquisition system for a vehicle 6717513: Electronic message delivery system utilizable in the monitoring of remote equipment and method of same 6717299: Isolation system for a motor 6716520: Structural reflective insulating material for ducts and other purposes 6716274: Air filter assembly for filtering an air stream to remove particulate matter entrained in the stream 6715814: Vehicle center console with integrally molded HVAC air passage 6715799: Corrugated pipe coupling having six degrees of freedom 6715690: Slope predictive control and digital PID control 6715246: Ceiling tile transmitter and receiver system 6712426: Motor vehicle front end structure 6712387: Method and apparatus for controlling deployment of a side airbag 6712280: Deep mass compensation for a vehicle automatic climate control 6712164: Vehicle having systems responsive to non-mechanical control signals 6712133: System and method for automatic temperature control in vehicles using predictive coding 6711767: Apparatus for warming a bed 6711470: Method, system and apparatus for monitoring and adjusting the quality of indoor air 6710929: Method of forming and using laser light columns 6710573: Method of controlling pulsed AC power 6709480: Self-supporting pleated filter 6709041: Instrument panel and center stack assembly 6708092: Method of grouping message identification and parameter identifications for a diagnostic system 6707447: Therapeutic and computer input gauntlet 6705938: Apparatus for controlling the environment of a parked vehicle 6705671: Electronically integrated vehicle support structure 6705533: Digital modulation for a gas-fired heater 6705523: System and method for delivering supplies to a production line 6704742: Database management method and apparatus 6704681: Method and apparatus for sensing microbial growth conditions 6703930: Personal alerting apparatus and methods 6703127: Macrocapsules containing microencapsulated phase change materials 6702875: Carbon fiber filters for air filtration 6702545: Venturi fan 6701772: Chemical or biological attack detection and mitigation system 6701725: Estimating operating parameters of vapor compression cycle equipment 6701288: Method and apparatus for designing and editing a distribution system for a building 6700310: Self-powered wireless switch 6700284: Fan assembly including a segmented stator switched reluctance fan motor 6700224: Security and energy control system 6700174: Batch fabricated semiconductor thin-film pressure sensor and method of making same 6700128: Apparatus and method for simultaneously germicidally cleansing both air and water 6699915: Foamed fireproofing composition and method 6699118: Vent apparatus 6698445: Fluid flow control damper assembly 6698219: Energy-efficient variable-air-volume (VAV) system with zonal ventilation control 6698215: Level sensory device and mounting bracket therefor |