It is difficult for most of us to imagine life without air conditioning. Modern AC units have come a long way over the past 30 years. Precise temperature control, humidity control and quietness of operation are all things we have been accustomed to.
But what did our great grandparents do to get comfortable? And how about their great grandparents – certainly air conditioning was not available then.
Or was it?
Air conditioning can be traced back to the days of the Egyptians, perhaps even before.
They used a method we can easily understand today. Early cultures, say 2,000 years or so ago, hung wet cloth or wet reeds in their window openings. Why?
Modern day example: Drive down the highway, roll your window down, and put out your hand. You hand will feel cool. Wet your hand first, and you will find that it is even colder than before.
The reason this occurs of course is because water on your hand is evaporating from its surface, and this evaporation causes one to feel colder. The less moisture or humidity the air holds, the more evaporation occurs.
So you see, any light breeze produced by the wet reeds produced the same type of cooling for Egyptians. You didn’t need to be rich or a political leader in those days to enjoy basic cooling.
In Arizona or New Mexico, temperatures get can get up to 115 degrees. The climate is so dry, there is almost no humidity. Use of cooling by evaporation is very common in these climates because it is so effective. With no complicated air conditioners, an evaporative cooler can drop the temperature from 115 degrees down to the 70s without too much effort.
Here, water is dripped over pads that can look like woven straw. Air is blown over. Sound familiar?
Evaporative coolers work by merely by having a fan blow over a “pad” similar to straw which has water dripped on it. The water evaporates by the fan blowing air, and immediately the air gets colder.
Seems the Egyptians were an inspiration for our modern day cooling system.
It’s nothing short of amazing to walk from an outside temperature of 110 degrees into a building cooled by this method and immediately see temperatures in the 70s or low 80s.
At Controlled Release Technologies our mission is to provide all HVAC users with innovative, proactive solutions to preventable HVAC problems.