The acronym ‘H-V-A-C’ or ‘aitch-vak’ stands for the functions of heating, ventilating, and air conditioning. HVAC systems are based on the science of mechanical engineering and work on the principles of thermodynamics, fluid mechanics, and heat transfer. HVAC systems are of specific significance for designing medium as well as large industrial and multi-storeyed office buildings, such as skyscrapers. HVAC systems’ three essential functions of heating, ventilating, and air-conditioning give the required thermal comfort and indoor conditioning of air. HVAC systems are workable at highly viable installation, operation, and maintenance costs. These industrial supply systems help in ventilation, reducing air infiltration, and maintaining pressure within spaces, indoors as well as outdoors. HVAC systems are also vital in providing safe and healthy building conditions in marine environments like large aquariums, where it is necessary to regulate the temperature and humidity, at near optimum levels, as well as allow fresh air ventilation from outdoors. Heating and air systems assist in getting rid of musty atmosphere indoors and bring freshness to a place, whether home or office, by ventilating the place to remove unpleasant smells and excessive moisture by effective air circulation, thereby preventing stagnation of the interior air.
The HVAC heating system provides electric or resistance heating by using a filament with the passage of electricity. Heated air is sent through forced air systems via ductwork. On hot days of summer, cool air can be sent via the same ductwork and thus be used for air conditioning. Pressurized gas is used in propane heaters to warm less insulated areas, such as patios, warehouses, and garages. Portable propane heaters can be taken out for outdoor activities, and hence are relied upon by people in the construction business and event planning, as well as by homeowners. Propane heaters are of different sizes, types and strengths. Portable heaters require no vent. They are lit by a match and can be wheeled around for easy transport, and also have a hooded shield, which helps to reflect heat downwards. These portable heaters are also used on decks and lawns for outdoor parties. The HVAC air cooling function, which helps in dissipating air, works on ventilating the area around the object, thereby resulting in cooling the object as well as allowing the object to have a larger surface area with increased flow of air. The HVAC ventilating process works on the same lines as cooling, whereby air is replaced to control temperature. This helps to remove odours, smoke, moisture, dust and airborne bacteria. Ventilation involves both the exchange of air as well as circulation of air within the building.