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We all know what is HVAC? (For those who don’t know, HVAC is heating, ventilating and air conditioning.) We also know the usage and requirement of HVAC in today’s world but were there usage of HVAC in our history? Well definitely we can’t imagine the Greeks or the Romans sitting in their rooms fitted with state of art air conditioning systems but we all know they were a smarter breed and they definitely must have had some or the other means to bring them thermal comfort. Let’s take a quick look as what form of HVAC system our history had, if there were any. We definitely won’t find anything similar or even near to the technology we use nowadays but there must be some form of comfort providing system. Let’s find out!
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This was a period of Greeks, Romans, Egyptians, Chinese and of course the Indians. While Egyptian’s used to use man powered fans, the Indians used to use rope fans. Roman’s used to use something known as hypocaust (a central heating system which has furnace in the basement and flues to distribute heat). It has a system for radiating heat for rooms and even steam for the bath of the rich. Chimneys were used extensively towards the start of 1400s which allowed people to have private rooms. It is also known that Leonardo Da Vince built water driven fan to ventilate a suite of rooms.
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In France, ventilating machines were used in the mines. These machines used to have a series of fans with blades which used to direct fresh air into the shaft. This was the time when the idea of houses with chimneys came to America from Europe. Large quantities of wood and coal were used during that era for heating their homes. Invention of thermometer by Galileo changed the way temperature was measured till then. Ferdinand II developed a thermometer independent of air pressure. This was the time when the very first gravity exhaust ventilation system was made for the US House of the Parliament.
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Initially many countries used to use stove built of bricks or fuller’s earth. Fahrenheit invented the first mercury thermometer. The first ventilator using centrifugal fan was made.
The era saw a series of important inventions that changed the lifestyle of the people of the whole world. Benjamin Franklin invented the very first stove which is supposed to be known as the first steam heating system. Then a series of some vital discoveries by Joseph Black including latent heat changed the way heat and temperature was perceived. James Watt brought a revolution by inventing the steam engine. A stove with a furnace for heating air was used in England. This arrangement had system of pipes which could heat up even big factories. Today that arrangement is known as direct fired heat exchangers.
Heat developed from friction was considered a form of vibrations. Carnot founded thermodynamics and James Joule discovered that work produces heat. Heat started to be considered as a form of energy. Hot water heating systems were used for large commercial and public buildings. Also the first warm furnace is developed. Houses with water spray system to humidifying and cooling were used. Supply air and exhaust air systems started to be driven by steam engines.
Also the law of conservation of energy is discovered. The first and second laws of thermodynamics were made. Boilers with higher capacity were used. Laws of gases were discovered and widely put to use.
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This era saw a sudden steep in the inventions and evolution of the HVAC systems. Furnace system with centrifugal fans, high pressure steam heating systems, massive fan systems and high speed centrifugal fans and axial flow fans with small electric motors were in extremely high usage. The first fan coil dehumidifying system was made by a company called Buffalo Forge. The same company made the first spray type air conditioning device. The first railway and industrial air conditioning system was devised by Sturtevant, including a backward inclined blade centrifugal pump. Buffalo Forge designed a system to remove dust particles from air streams.
The HVAC industry started using Scotch Maine type boilers with oil and gas burners and induced or forced type fans were used. A system which brings down the temperature to 10 degree Fahrenheit but increases the humidity to uncomfortable levels was made. The Rational Psychometric Formulae for fundamental calculations was invented. A forced air system which uses a fan was made. The first centrifugal refrigeration machine was made for air conditioning large spaces.
Hydronic circulatory pumps and radiators started to be used in the air conditioning systems for circulating water in the system. The first refrigeration with a compressor was made. The first residential air conditioning was made. Room coolers that use the technology of the refrigerators were made. Panels for heating floors and ceilings started to be made. The use of solar power as a power source was made. The first man walks on moon with life support and cooling systems
The heating pump heats on the reverse refrigeration cycle and on lower outdoor temperatures. Due to the over usage of refrigerants the environment was endangered and thus the United Nations Montreal Protocol for protection of earths ozone layer was signed. With the help of international co operation chlorofluorocarbon (CFC) which depletes ozone layer was phased out from usage. A multi million dollar research program on air conditioning and refrigeration system began.
The history is in the making...
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Hvac fundamentals : Samuel C. Sugarman