Supply and Demand: The push to understand building energy use | EXPLORE→

The Case for Unconditioned Air

With all of the conversation right now around worker’s rights and workplace amenities, it is easy to forget just how far we have come. In fact, only a few generations ago the comfort of workers was secondary to their productive output. No story illustrates this better than the plight of the Sackett-Wilhelms Lithographing & Publishing Company in Brooklyn, New York. In 1902 the company was having trouble with its printing presses, the publishing platform of choice for the social media of the age. The problem was that the warehouse where they ran their presses had large swings in its internal humidity. This would cause their paper to expand and contract and would produce distorted printed images. The humidity swings were caused by, well, nature. At the time there were no ways to control humidity besides blowing fans and as anyone who has tried to beat the heat in front of a fan will tell you, they can only do so much. 

Luckily for the Sackett-Wilhelms Lithographing & Publishing Company, and for all of us, a young engineer, fresh out of college, named Willis Carrier submitted a drawing for a machine that would blow air over cooled coils. Carrier’s employer was already making heating coils so he wondered if the same principle would work in reverse. It did, but not enough to meet the printer’s specifications of no more than 10 degrees variance in indoor humidity. The failure led Carrier to continue improving on his idea until it eventually worked but even then, the fact that what was being called an apparatus for treating air also cooled the often miserable air temperature inside factories was nothing more than a pleasant byproduct. 

The first commercial use of these air cooling apparati didn’t come until after the first world war. The Rivoli Theater in Times Square approached Carrier (his former employer sold the rights to the invention to Carrier because they didn’t see a future in it) to install the first of his machines. Theaters were an obvious place for this kind of invention, they packed people closely together indoors in heavy clothing that was, for some reason, the formal attire of the time. Previously theaters used fans blowing over ice to help keep them enjoyably cool but there were limits to that technique. In the summer of 1880, New York’s Madison Square Theatre reportedly used four tons a day per day to help keep its patrons comfortable but would often get complaints about the unpleasant smells being released by the ice that was harvested from New England’s increasingly polluted lakes. The Rivoli Theater’s investment paid off, moviegoers flocked to the theater on summer days just as much to beat the heat as to watch the latest cinematic adventure. Other theaters followed suit and the result was the ongoing phenomenon of the summer blockbuster. 

Now air conditioning is standard issue for most buildings. The technology was the catalyst for the population growth of almost uninhabitable hot areas like the American Southwest. Economic divides can be seen in the adoption of AC. There are 1.6B installed air conditioning units in the world and 67 percent of them are in just 3 countries: China, the US, and Japan. The current household penetration rate for air conditioning is above 90 percent in Japan and the US, 60 percent in China, and is still below 20 percent in developing countries like Mexico, Brazil, Indonesia, and India. The United States has about 40 percent of worldwide capacity. There is a cultural divide separating AC usage as well. In China the vast majority of air conditioning units are installed in residences while in Europe they are much more common in commercial buildings.

Air conditioning has also allowed for the construction of tall buildings, many of which were built to be so reliant on air conditioning that they don’t even have windows capable of opening. There are plenty of reasons not to put opening windows on tall buildings. They are more expensive, they can take away from the architectural look of the building, and they represent a liability as anything that gets thrown from them could be harmful or deadly to someone below. Perhaps most importantly they protect the integrity of the building envelope which is particularly critical in high rise structures where wind forces vary from top to bottom. But windows do have important benefits. They can help a building cool or heat itself without the use of air conditioning and can help air quality by bringing in fresh, outside air (note: some outside air is obviously fresher than others). The ability of buildings to bring in uncontaminated air became front and center during the pandemic, many buildings were told to bring in as much outside air as possible, no matter the costs of heating or cooling it.

Now we are starting to see buildings designed in a way that makes them less reliant on air conditioning. Uber’s new headquarters in San Francisco is a great example of this. It has  14-foot-tall glass panes that open and close automatically to regulate the conditions inside an atrium that connects the entire building vertically. These windows are connected to the building management system and are placed strategically around the building in places with different wind and sun exposure. The team behind the project says that the windows led to about a 20 percent reduction in mechanical systems and the atrium areas of the building are used as informal gathering spaces so employees can connect with each other and stop to smell the roses (or whatever other scents are wafting in from outside). 

We owe a lot to air conditioning. It has helped keep us comfortable in our homes and our workplaces, even areas that humans historically have struggled to survive. But our reliance on air conditioning is one of the things that is keeping us from lowering our energy consumption to a sustainable level. A new breed of building is turning back the clock by opening up the windows, representing a change in how we achieve the comfortable temperatures that we crave. These buildings are the exception, not the rule, though. The vast majority of large buildings are still sealed boxes that need artificial heating and cooling in order to be usable. In order to stretch our resources, we all might have to get used to using the air conditioning less, even if it means a bit of discomfort. This might seem like a step backward but is still a far cry from the sweltering factories at the turn of the 19th century that were more worried about humidity’s effect on their product than the temperature’s effect on their worker’s comfort.

Image - Design