Air Conditioning Appreciation Days are celebrated from July 3 to August 15 of every year to honor the invention and role of air conditioning in modern society.

An engineer named Willis Carrier invented the first cooling system (aka air conditioner) to help dry ink faster in a print shop. Was the device rather basic compared to today? Sure, but he soon improved upon it, and comparing it to the cooling methods that came before it, well … Eureka!

Like most creatures, humanity has craved thermal comfort since crawling out of the oceans. As necessity is the mother of invention, let’s look at some of the ways we’ve cooled off through the ages:


We don’t call them cavemen for nothing!

The first humans learned that sheltering in caves or beneath the earth was cooler than outdoors. In fact, some dug burrows. No wonder many people find meercats so fascinating. We could call such living conditions uncivilized, but in their own way, primitive man utilized a concept we use today called Geothermal Cooling.

More intriguing, caves enabled the construction of the first air-conditioned building in the United States. A ventilation engineer named T.C. Northcott built the Limair Sanatorium over Virginia’s Luray Caverns, designing the building to utilize that cool air from below ground to regularly exchange all the air in the building in five minutes.


The answer is blowin’ in the wind.

People without the technological ability to fashion more complex devices to cool themselves found simpler ways, using evaporative cooling almost instinctively. Way back, Egyptians hung wet reeds against the breeze to counter the Nile Valley’s intense heat. More recent history saw wet sheets or curtains hung in windows to catch moving air.

Along that same concept, U.S. Naval engineers cooled the room of a dying President James A. Garfield using a blower to force air through a box that housed cotton screens cooled by ice water. They sent the air into the room via a duct. The ‘unit’ brought the temperature in that White House room no higher than 80 degrees.


The way of water.

While the first aqueducts came about in Mesopotamia, the Romans improved upon them. Transporting water not only supported irrigation of crops, but pipes ran from some aqueducts through building walls to cool the indoors–if you were lucky enough to be higher on the food chain, that is.

Around 1000 BC, Ancient Iran created ‘qanats’ or tunnel systems. Like aqueducts, they transported water, but they also became passive cooling systems. Hot air traveled underground through air shafts via gravity. The air became cool thanks to passage over the water-filled qanat before working its way up wind towers to escape into basements. Qanats are still used in some places today.


The best HVAC innovations look to the future and the past.

Thanks to and because of technology, today it is critical to ventilate, heat, and cool our indoor environments as efficiently and passively as possible if we’re going to tackle decarbonization. Perhaps we can look at the challenge as ‘back to basics’ through better technology. What comes to mind? The mechanical ventilation and thermal comfort advantages of ERVs.

High-efficiency ERVs are the way to go for the thorough air exchange displacement Northcott sought with his experiment in cooling via underground caverns. They operate on a similar concept to the Qanat where air enters a ‘core’ that affects the temperature of the air before sending it back out transformed.

At BPE, we’ve looked to the past for inspiration and developed patented technology for inventing ERVs with superior efficiency and the best indoor air quality you can get. Plus, we understand what’s at stake when it comes to the planet. Check out our line of BPE Energy Recovery Ventilators to discover how you can enjoy winning HVAC in residential and commercial spaces: Put health first, save money, do your part to lessen the building industry’s effects on the environment and yes … stay comfortable indoors!