An HVAC control system is a computerized mechanism used to adjust heating, air conditioning, and ventilation components within a building. It may feature manual or automatic operation, and is often customized base on the specific demands of each building. 

Amperage is a term often used by electricians, and means electrical current, measured in amperes, or amps. The ampere is the SI unit for electrical current, or the amount of electrical charge that flows through a conductor in a given time. One ampere is a charge of one coulomb — about 6.241 X 1018 electrons — per second flowing past a given point. 

Amperage must be controlled in order to protect the electrical wires and circuits from overheating or short-circuiting. This is why electricians use fuses and breakers. A 30-amp fuse, for example, will allow smaller appliances to run on the line it protects, but if an electric clothes dryer pulls 60 amps, a metal filament in the fuse will melt and break the circuit immediately. Breaker switches also control current through circuit breaking. Larger electrical devices often have their own circuits with higher capacity fuses or breaker switches to avoid such overloads.

 

A variety of cooling agents, or refrigerants, are used in the average household. Freon® in air conditioning units, hydrofluorocarbons (HFCs) in refrigerators, and chlorofluorocarbons (CFCs) in aerosolized products are just a few common examples of refrigerants encountered on a daily basis. 

While these chemicals have their uses, it has also been proven that they can harm the environment and deplete the earth's ozone layer when left unchecked or disposed of improperly. Refrigerant recovery is a sector of the environmental industry that works to collect and re-purpose these and other such chemicals, or to properly dispose of the chemicals in a manner that does not harm the environment.

Heating, ventilation, and air conditioning (HVAC) systems usually require routine preventive maintenance to keep them in proper working order. Large units that are used in hospitals, schools, factories, and office buildings are usually maintained by skilled HVAC technicians. Simple maintenance and repair jobs on home heating or air conditioning units can usually be performed by individuals with relatively little knowledge or experience with HVAC systems. HVAC preventive maintenance helps to reduce wear and tear, improve the efficiency of a system, and extend the life of a unit.

Some manufacturing plants, hospitals, and other large buildings staff full- or part-time specialists to perform HVAC preventive maintenance and make emergency repairs when necessary. Many repairmen and women have detailed knowledge of every aspect of a system, including the structure and function of air vents and the interior of mechanical engines. They understand the organization of belts, fans, gears, and wires, and know how to make sure that everything is kept in proper working order. Professionals might consult operators' manuals and blueprints to help guide them through maintenance jobs.

Individuals who have systems installed in their homes might hire technicians to perform detailed maintenance jobs, though many people are able to handle simple HVAC preventive maintenance tasks themselves. It is usually fairly straightforward to maintain small air conditioning, heating, or refrigeration units with basic tools and common sense. Owners' manuals often come with detailed instructions on how to maintain a unit.

Chlorofluorocarbons are manmade chemical compounds composed of three types of atoms: chlorine, carbon, and fluorine. These compounds were in household products and as a fire retardant for decades, and are believed to have caused serious damage. In addition to potentially causing illness due to exposure, chlorofluorocarbons have been banned throughout much of the world for their devastating effect on the ozone layer of the Earth.

In the 1890s, a Belgian chemist was able to produce chlorofluorocarbons, also called CFCs, in a laboratory. It was not until the 1920s, however, that their use became widespread through the efforts of inventor Thomas Midgely. Midgely had already achieved considerable fame for the invention of leaded gasoline, despite the profusion of workers contracting deadly lead poisoning during production. First used to replace the dangerous gases that were used in refrigeration systems, CFCs were quickly adapted for use in air conditioners, aerosol cans, military aircraft, and hundreds of other products.

Some experts consider chlorofluorocarbons to be one of the most deadly greenhouse gases ever invented. According to some estimates, a single chlorofluorocarbon compound can destroy 100,000 particles of ozone, allowing dangerous ultraviolet rays to filter through to the Earth's surface. Additionally, chlorofluorocarbons absorb massive amounts of heat, which is then reflected back to the planet. On top of both these destructive functions, CFCs can also survive in the atmosphere for at least a century, meaning that they may continue to cause atmospheric damage for over a hundred years after bans take effect.

Another very common use of aluminum duct is as a dryer duct. Clothes dryers use high heat to dry clothes, converting the water in the clothes to water vapor that is then vented out of the home. Aluminum duct is commonly used in this application because of its resistance to corrosion. A duct can transport moist air for many years without the threat of rust. The cost of these aluminum ducts is generally low due to the small diameter of duct needed.

Many believe that the best way to keep your home cool during the summer is to use an air conditioner to keep the temperature down, but there are other options. Something you may not know about your air conditioner is that it runs far more efficiently when it is properly cleaned and maintained. Even if it hasn't been used recently, the filter may need a good cleaning. Not only will your air conditioner do a better job of keeping your home cool when it is properly cared for, but it will also use less electricity.

Another good idea is to use a dehumidifier. Excessive humidity can cause the temperature to feel higher than it actually is. Reducing the humidity level is a good way to make your home feel cooler and to keep it more comfortable.

A classic use for an exhaust fan is in an environment like a kitchen or a bathroom. These locations tend to get filled with steam, and steam can promote the development of mold, which is not desirable. An exhaust fan can be used to vent the warm, moist air to the outside, where it can disperse harmlessly. Exhaust fans can also vent cooking odors outside so that they do not linger indoors, and when people cook smoky foods, the fan can help keep the air in and around the kitchen clear.