Heating, Ventilation, and Air conditioning (HVAC) are the science of vehicular and indoor environmental comfort. Its purpose is to offer acceptable indoor air quality and thermal comfort to its users. The process includes the modification of the existing environment by adjusting the temperature, humidity, and relative humidity. The result is increased comfort level and a more comfortable work atmosphere. It also helps to reduce energy consumption in indoor environments.
Heat pump technology is the most commonly used technology in HVAC. It involves the use of heat sources such as electricity for heating and cooling purposes. Heating sources are usually air or water. Some HVAC systems also use solar power as an additional source of energy for heating and cooling.
One type of HVAC is the Direct Air Furnace (DAF). It is an evaporative cooler that removes moisture from the air and then condenses the water droplets into a liquid form. DAFs uses an open vent configuration. This is one of the simplest forms of HVAC and may be operated using natural gas, oil, or coal. An evaporative cooler is not an efficient heating or cooling system because it does not have the thermal efficiency of later types of HVACs.
Another type of HVAC is the forced-air furnace. It is an AC (visible) machine that burns liquid petroleum fuel to produce hot air. It is often used in applications where there is an excess of demand for hot air but not enough supply to meet the requirement. As HVACs have become more efficient over time, they are now frequently used instead of forced air cooling and heating systems.
A third HVAC type is the indirect vent furnaces. This furnace operates by utilizing the exhaust gases from another furnace to heat the dwelling. The difference between an indirect and direct vent furnace is that the latter places the combustion product or fuel at a distance from the heating unit so that any moisture drawn by the heating process is diverted to the ventilation stream instead of being vented directly to the outside. This type of furnace has a closed-loop system and requires an extra stage of ventilation before it becomes fully efficient.
The variety of HVAC systems is vast. It would be very difficult to name every type of HVAC system on the market today. Some have only one purpose; to provide fresh air to the living space. Some are for industrial and commercial settings, and others are geared toward home heating. For the home user, however, a few different types of HVAC are available to meet the diverse needs of the homeowner. The first step to purchasing a new one is to determine the home owner’s specific needs.
Directly vented HVACs are ones in which the combustion product is burned as opposed to being drawn through ducts into a cooling system. For homes with older HVAC systems, this may not be such a big deal, but it does pose a safety hazard. With a direct-vent system, if there is a buildup of flammable materials, such as paint or varnish, this can result in serious consequences. Newer models of direct-vent heating and cooling units do not have this problem because the product is burned only inside the HVAC.
Another important term to be familiar with is “air-conditioning” or “heating.” Air-conditioning and heating are terms that are commonly used interchangeably, but they are actually two separate systems. AC is the abbreviation for “amps,” while HVAC is short for “heating, ventilation and air conditioning.” Air conditioning uses AC mixtures with variable speed fans to provide cooling. Heating uses natural gas, oil, or propane to provide warmth, while VAC uses electricity, mechanical motion, or an ionization source to create humid or damp air.