Modern refrigerants have been developed to be more environmentally safe than many of the early chlorofluorocarbon-based refrigerants used in the early- and mid-twentieth century. These include HCFCs (R-22, as used in most U.S. homes before 2011) and HFCs (R-134a, used in most cars) have replaced most CFC use. HCFCs, in turn, are supposed to have been in the process of being phased out under the Montreal Protocol and replaced by HFCs such as R-410A, which lack chlorine.[14] HFCs, however, contribute to climate change problems. Moreover, policy and political influence by corporate executives resisted change.[15][16] Corporations insisted that no alternatives to HFCs existed. The environmental organization Greenpeace provided funding to a former East German refrigerator company to research an alternative ozone- and climate-safe refrigerant in 1992. The company developed a hydrocarbon mix of isopentane and isobutane, but as a condition of the contract with Greenpeace could not patent the technology, which led to its widespread adoption by other firms.[17][18][19] Their activist marketing first in Germany led to companies like Whirlpool, Bosch, and later LG and others to incorporate the technology throughout Europe, then Asia, although the corporate executives resisted in Latin America, so that it arrived in Argentina produced by a domestic firm in 2003, and then finally with giant Bosch's production in Brazil by 2004.[20][21]

The condensed, pressurized, and still usually somewhat hot liquid refrigerant is next routed through an expansion valve (often nothing more than a pinhole in the system's copper tubing) where it undergoes an abrupt reduction in pressure. That pressure reduction results in flash evaporation of a part of the liquid refrigerant, greatly lowering its temperature. The cold refrigerant is then routed through the evaporator. A fan blows the interior warm air (which is to be cooled) across the evaporator, causing the liquid part of the cold refrigerant mixture to evaporate as well, further lowering the temperature. The warm air is therefore cooled and is pumped by an exhaust fan/ blower into the room. To complete the refrigeration cycle, the refrigerant vapor is routed back into the compressor. In order for the process to have any efficiency, the cooling/evaporative portion of the system must be separated by some kind of physical barrier from the heating/condensing portion, and each portion must have its own fan to circulate its own "kind" of air (either the hot air or the cool air).


This is a great option for cooling your home or business without having to deal with the ductwork.  Other systems require ductwork so that the cool air can travel throughout the space.  A ductless mini split air condition doesn’t require ductwork because it has an air conditioner or a heat pump outside that connects to units in the home that handle the cooling being pushed into them from outside.  You can control the temperature of a whole home or just one room by controlling the air handlers in each specific area.  This allows for more control and a more efficient way to control the temperature and cost of operating the ductless mini split air conditioner.


Moncrief provides a wide range of services from high-quality energy-efficient systems, tune-ups and inspections, as well as repairs in the Roswell and Marietta areas. As a full-service heating and cooling company, we stay up-to-date on the most economical and energy-efficient systems available for your home or business. In addition, our technicians are well-trained in a wide range of systems to provide quality and cost-efficient furnace service, repairs and installation.
In 1992, a non-governmental organization, Greenpeace, was spurred by corporate executive policies and requested that a European lab find substitute refrigerants. This led to two alternatives, one a blend of propane (R290) and isobutane (R600a), and one of pure isobutane.[18][22] Industry resisted change in Europe until 1993, and in the U.S. until 2011, despite some supportive steps in 2004 and 2008 (see Refrigerant Development above).[27][67]
The basic concept behind air conditioning is said to have been applied in ancient Egypt, where reeds were hung in windows and were moistened with trickling water. The evaporation of water cooled the air blowing through the window. This process also made the air more humid, which can be beneficial in a dry desert climate. In ancient Rome, water from aqueducts was circulated through the walls of certain houses to cool them. Other techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season.[5]
Need your air conditioning repaired today? Let Dunes Heating and Air Conditioning LLC.  same-day air conditioning repair service come to the rescue. Our air conditioning repair, maintenance and installation technicians and contractors are some of the most highly skilled AC repair technicians in the area. So whether you need your commercial air conditioner repaired or your home air conditioning system replaced, let our team of factory trained and certified home central air conditioning repair technicians be there for you and your family!
When it comes to furnace repair, Roswell and area residents can rely on us for fast and efficient repairs. Moncrief has continued to be a consistent provider of heating and cooling services in the Roswell and Marietta. We have worked hard to gain your respect by providing quality services and products, and delivering on our promise of total comfort for your home and family while providing energy and cost savings.
First off, HVAC stands for “Heating, Ventilation, and Air Conditioning,” while AC stands for just the last part: “Air Conditioning.” In other words, when we talk about AC, we’re generally talking about the system that cools the air in your home (although sometimes people do use the term AC to refer to units that provide heat as well, especially when they’re talking about heat pumps). However, when we talk about HVAC, we could be talking about a system that does either the heating or the cooling, or both.

The Chartered Institution of Building Services Engineers is a body that covers the essential Service (systems architecture) that allow buildings to operate. It includes the electrotechnical, heating, ventilating, air conditioning, refrigeration and plumbing industries. To train as a building services engineer, the academic requirements are GCSEs (A-C) / Standard Grades (1-3) in Maths and Science, which are important in measurements, planning and theory. Employers will often want a degree in a branch of engineering, such as building environment engineering, electrical engineering or mechanical engineering. To become a full member of CIBSE, and so also to be registered by the Engineering Council UK as a chartered engineer, engineers must also attain an Honours Degree and a master's degree in a relevant engineering subject.


An air handler contains the components that move the air throughout your home, called the blower. It is usually set inside the home and operates with both the heating and cooling components of your HVAC system. If you take a quick look at an air handler, it may closely resemble a furnace. Air handlers can run with an air conditioner and contains the indoor coil, used to cool and heat your home depending on which system it’s running with.
A packaged system is a single unit combining all the components described in the split system. Since the unit is a package, it must be placed outside the building and indoor air is “ducted” from the building to the packaged system and back through an air distribution system. These units typically have SEER rating from 10 to 18. If heating is required, an alternate method of heating the interior of the building must be used, usually in the form of electric or gas heating.
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