Dear friends and family and pets,
We generally take the systems that surrounds us for granted. Ask yourself, what is an air conditioner? The answer would be rather childish: « It is a magical machine that can turn any room into a fridge » ; « it’s a winter maker. » But do we really know what an air conditioner or heater does? Well, as rising architects, we definitely should.
Let’s first think about the culture of living indoors. Our bodies evolved and became adapted to the external weather variations. But around seven generations ago, we the human kind became fond of living in constructed shelters, the buildings that we build, that are nothing more than a re-interpretation of the cave we once have inhabited. In class we talked about the ways humans used to control and create new indoor temperature. In medieval times we would just make a fire in the middle of the room. Then, we actually created a little enclosure were the fire would be lit: the fireplace.
In the image above we can see various niches on the wall’s thicknesses: this is where the fireplaces are placed. We can always notice that almost every single room in that building in particular has a fireplace. This is due to the human nature of wanting to control indoor temperature.
We evolved and technology evolved and the human being created something called a boiler, which is nothing more than a steam generator. It is a device that creates steam by adding heat energy into water. It basically heats water and makes that heated water circulate through a building by pipes.
The diagram above above shows us roughly how a boiler works. There is the actual boiler (in black) that is often hidden down below in a dark basement or outdoors. and it heats up the house
Air conditioners, on the other hand, it’s a device that moves heat out of a room. It sucks. I mean, it sucks the heat out of the room, and dumps it somewhere else, outdoors. In between that process the air goes through a refrigerating mechanism. This mechanism manipulates the pressure and the consequently the boiling temperature. Let’s take a closer look at the refrigeration machine: There are two basically two kinds of coils joined by a bulky, heavy compressor and an expansion valve. The evaporater coil transforms a cold liquid into a cold gas. Then you compress it. Then the cold gas become a high pressure gas that becomes a high pressure liquid in a condenser coil. This liquid goes through an expansion valve and the process restarts. It is a closed loop.
The thing that needs so much energy is the compressor. That is why your energy bill is so high. This is why the energy bill back at my hometown of Manaus is so high. This brazilian city and many others are really air conditioner dependent.
Strategies for cooling
Air conditioners, though are not the only forms of cooling a space; dry and hot weathers shoud taker advantage of a process called « evaporative cooling ». Below is a diagram of a Evaporative cooler. Evaporative cooling takes advantage of the water great enthalpy of vaporization. The temperature of hot dry air can be diminished significantly when the phase of water goes from liquid to vapor. This is because vapor requires much less energy.
Another system takes advantage of the peak loads during the course of a day. It is a strategy of not using energyduring the peak load. You run a refrigeration during the night and it creates something like a big block of ice. This block of ice will be used to cool the building during the day. That way it won’t be necessary to run a compressor during the day when everybody else is doing the same. This concept really struck me during the lecture, I have never though about that before.