Thanks to modern technology, most of us are spoiled to a life where we don't have to worry about living without central heating and air. Simply trying to imagine a hot summer day or freezing winter night without it seems unreasonable. However, this wasn't always the case and as much as we like to ignore it, there are still places today where heating and air conditioning are not available. Here is a brief history of central heating and air and how we came to be so fortunate.
Air conditioning was said to be used in ancient Egypt by the ruling classes and their technique used water to cool masonry. Even though water was a precious natural resource in that area, they saw the need to use it for more than just hydration and sanitation needs. As primitive as this technique was, it was an amazing example of how early technology was developed.
Early heating systems used wood as the primary fuel source up until the 1900's,which is when coal became a practical heat source and cast iron stoves were invented to burn it. Dave Lennox, of Lennox brand furnaces, was the first to pioneer a steel riveted coal burning furnace in 1885. Shortly after this, early pioneers, such as Stuart Cramer, a textile mill owner, began experimenting with various dry air cooling techniques in order to humidify the air in his factory. He coined the phrase "water conditioning" at that time and filed a patent for his technology.
As cooling systems continued to develop, inventors started using compressed ammonia as the main refrigerant, rather than water. Eventually, this transformed into the compressed gas cooling systems that we use today.
As technology improved and a need was discovered for a way to actually circulate the hot and cold air, blowers began to be designed that could replace the need to "stoke" a fire and improve the already popular convection heating methods. The 1950's gave rise to the popularity of central cooling systems, which eventually gave way to the central air units that we use today.
These days, Air Conditioning units use compressed gases to cool the air, while a majority of the heating systems use either gas or water. Systems of ductwork were designed and implemented that could circulate both hot and cold air depending on the needs. The United States currently uses 20% of its energy to fuel the electricity needed to cool buildings. As more and more systems continue to move from fossil fuels, this can only increase.
We should consider ourselves fortunate that these systems developed as they did, otherwise we would be spending our days and nights as our ancestors did. It is hard to imagine that only recently has central heating and air become a viable option, but we are often reminded of it when we visit old buildings that have only old heating systems. We are so used to living with this technology that these days, offices and schools shut down without heat or cooling. Sometimes we forget just how lucky we are.
This article posted Jan 17, 2009.
