Why are the heater cores located under the window?

The reason for this is that this area is idle and there are no beds, cabinets, armchairs, etc. to be placed in the room. You can think of it as leaving room for items such as in other parts of the room. Yes, it seems like a partially logical thought, but that’s not why.

In this article, we will explain to you why such an application exists.

Although the windows are well insulated, we know that there is a cold air flow from there and this is the coldest part of the room.

Most people think that because the air heated by the honeycombs directly encounters this cold air, the heat is trapped in this area, and therefore the heating of other parts of the room takes place later. When approaching this situation with such an idea, the honeycombs placed in front of the window may seem meaningless. But of course, the process does not go as expected here.

A simple knowledge we learned in middle school actually explains this situation easily.

Warm air rises, cool air descends. Because the air molecules in the heated air dilute, expand and become lighter. Since its density will decrease, the pressure it will exert on the unit surface on the ground will decrease. For cold air, the situation is the opposite. The best example of this is hot air balloons.

For this reason, honeycombs placed in front of the windows appear as the most logical place in terms of rapid heating of the room. So why?

As the warm air coming out of the honeycomb rises towards the ceiling, it insulates the room by forming a direct barrier against the cold air coming from the window. Thanks to this barrier, while the cold air descends directly towards the core, it also helps to push the rising hot air into the room faster.

As an example, the following image will be explanatory:

While the hot air rising to the ceiling is moving towards the opposite wall, it is being pushed back towards the honeycomb due to the air circulation as it cools down. Thanks to this constant thrust and the circulation experienced, every part of the room heats up faster.

So the trick here is; the direct encounter of the hot air with the front of the window, which contains the coldest air of the room, and pushing it rapidly.

If the honeycomb was placed on a wall opposite the window, a heat barrier would form near the middle of the room. The window part of the room would remain cold compared to the other parts, as the thrust was low and the warm air had difficulty getting out of this area. Therefore, it is very important that the honeycombs are placed in front of the window that contains the coldest air in the room.

Source: Stack Exchange, Little-Knights, Siemens