Have you ever taken the time to check over the new Heating as well as A/C units today. Look at the new HVAC tech and compare them to the older models years ago. This was something I never had thought about. When I got bored late one night, I decided to search around on the internet. The internet is a great source of information on heating and a/c. I was able to find some fantastic information on the different models of HVAC and how they changed over the years. I started comparing the old and new central heating and a/c systems! When I began my research you would not believe what I genuinely found! There was a whole lot of information on a/c and heater models. In the formation of heating and cooling, there were no functions like controlling humidity, zone control or even air quality. Also the first AC unit was mainly a fan that blew ice over air. The oil heating systems used an actual container filled with oil in order to heat the home. Basically they used some energy sources like gas, wood or electric in order to heat. Radiant flooring and boiler systems took awhile to start. When I was a child we had window a/c units and a space heater. So I didn’t know anyone who had central HVAC. It was wild when homes had one giant box that contained both heating and air.