Dehumidifying Cooling - Alternative Systems
The term air conditioning refers to the process of providing heat comfort and dehumidification of the air in the interior by cooling. In a broader sense, the term HVAC is also used for heating, cooling and ventilation or disinfection processes to improve the condition of the air.
It is a modern invention to transport heat using machines to provide air conditioning, cooling buildings is not. It is known that the ancient Romans circulated the water coming from the aqueduct on the walls of those houses to cool certain houses, because water is expensive to use in this way, only wealthy people could afford such a luxury.
In medieval Iran, there were buildings that were cooled in the hot season with cisterns and wind towers.
In 1820, British scientist and inventor Michael Faraday discovered that compressed and liquefied ammonia cools the air when it can evaporate. In 1842, Florida doctor John Gorrie used compressor technology to produce ice, which he used to cool the air in his hospital in Apalachicola. used. He hoped to use his ice maker to eventually adjust the temperatures of the buildings, even thinking of a centralized system that would cool the entire city.
Today, operating rooms in hospitals (where the air is filtered to reduce the risk of infection and humidity is controlled to reduce the patient's dehydration. While special applications such as heart surgery require low temperatures (about 18°C), and others such as neonatal wards need relatively high temperatures (about 28°C) is needed.
Air conditioning has become a compulsory use in topics such as laboratories, data processing centers, plant growth areas, nuclear facilities, mines, cooking and processing areas, and even aircraft air conditioning.
Nowadays, due to the necessity of these applications, topics such as high operating cost, less energy emission and carbon footprint have come to the fore. There have been developments especially in cooling systems, and with these developments, dehumidifying cooling systems have emerged as alternative systems. These systems have features that will provide the desired indoor air quality and contribute to the global warming of today's problem by reducing the increasing threat against the ozone layer.
In addition to reducing the initial investment cost and saving energy in dehumidifying cooling systems, the main purpose is to use them in special application areas. Areas where dehumidification cooling systems can be successfully used are supermarkets, schools, restaurants, military warehouses, ski and skating rinks and indoor swimming pools. In addition, most facilities with insufficient dehumidification capacity can benefit from dehumidification cooling systems as additional dehumidifiers.
Moisturizing Materials
The desiccant material holds or releases moisture due to the moist air and the difference in vapor pressure on its surface. Solid desiccant substances used in the adsorption process store water molecules in their surface pores and no chemical change is observed in them. Liquid desiccant materials used in the absorption process can generally hold more water than a unit amount of solid desiccant material, but as the amount of water retained increases, the operating problems of the system increase. Silica gel, active alumina, lithium chloride salt and molecular sieves are mostly used as solid dehumidifiers. In addition, titanium silicate and synthetic polymers are new generation solid dehumidifiers developed to make cooling applications more efficient. Liquid dehumidifiers are lithium chloride, lithium bromide, calcium chlorite and triethylene glycol solutions.
Simple Dehumidification Cooling Systems (Stand-Alone)
These systems are very economical systems that do not contain CFCs. Especially in humid areas, it can be applied successfully to meet all thermal comfort conditions.
Conventional Cooling Supported Dehumidification Cooling Systems (Latent-Load Reducer)
When the conventional vapor compression cooling system and the dehumidifying cooling system are combined, systems generally defined as hybrid systems emerge. The main purpose of the dehumidification cooling systems is to meet the specific system needs, rather than reducing the initial investment cost or saving energy. In addition, today in developed countries, these systems have come to compete with conventional vapor compression systems, which are well known in both industrial and comfort applications.
Damage from Humidity of 70 Million Dollars a Year
According to a study in the USA, these systems have the potential to save 422 million GJ of energy per year and to prevent more than 20 million tons of carbon dioxide emissions. According to the report of the American Hotel and Motel Association, the damage caused by high humidity to hotels and motels reaches 70 million dollars per year. These systems purify unpleasant odors and particles from the air. Thus, they provide healthier and more comfortable environments.
In Turkey, these systems are almost never implemented, not recognized, and lack of knowledge and confidence about performance and cost efficiency are the biggest obstacles to their implementation. (computer programs etc.), the creation of real performance data will encourage the use of these systems much more.
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