# Tag Info

## New answers tagged convection

0

As the hot air goes up and the cold air goes down, the radiator is located where there is a better circulation, ie, even though the window is double glazed, there will always be cold air entering the division by the material itself. So the cold will push the hot air inside the room. Another explanation can be the fact that external walls can have thermal ...

1

Because under window is the place where delta-T (the Change in Temperature) is largest in the whole room. The larger is delta-T, more efficient the system is. Window even when closed is still a coldest place, because it is a thinnest wall. Cold air flows downwards, thus under window. What is an efficiency of a radiator depends on whether your goal is to ...

-1

Its because the hot air that is created by the radiator heats the colder window making the glass warmer... therefore the glass is allot less likely to condensate and at the same time keeps the room allot warmer because the heat will radiate out wards away from the window along with any drafts or such ... also if the radiator is placed on a wall without a ...

1

Reason is quite simple. If you have a window without radiator and outside is really cold, the window glass would be cold as well. This will lower temperature of the air around the window and this air will flow immediately down (physics). So if someone want well heated room with very cold floor .. do it, put radiator to opposite side. That's why it is wise ...

0

A number of reason: - the wall under the window is basically useless - placing the heater under the window allows you have a more even temperature throughout the room: the window is the coldest place in the room, if you were to place a heater on the other side of the room and wanted to reach a certain temperature by the window, the other part of the room ...

3

As the hot air goes up and the cold air goes down, the radiator is located where there is a better circulation, i.e. even though the window is double glazed, there will always be cold air entering the division by the material itself. So the cold will push the hot air inside the room. Another explanation can be the fact that external walls can have thermal ...

38

Since this is a physics forum I assume the OP is interested in a quantitative answer in terms of the efficiency of the system and how it differs based on the relative positioning of heat sources and heat sinks. The math required to analyzed such a system is too much for me to manage right now, but I believe the following principles apply and are objectively ...

6

As described in the other answers, putting the radiators (or hot air vents in a forced-air system) under the windows offsets the greater heat loss of the windows, but there is another reason. As room air flows over the surface of a window, it will lose heat to the window (and the outside). This can cause moisture in the air to condense out onto the window. ...

7

As Programmer mentions, by putting the radiator in front of the area most prone to heat loss and ingress of cold air, you are effectively screening off the room from cold air. However, there is also the fact that radiators are often quite a bit hotter than other heat sources such as forced air. Therefore it makes sense to put it in the coldest part of the ...

52

The reason is because the heat loss occurs mostly in the windows and the fenestration. The idea is that you would like the incoming air to be heated up. Also, it creates an air curtain that prevents more heat from being lost through this exposed areas. The final reason is to make the temperature of the room more or less uniform. If the heaters were placed at ...

1

My guess would be it's there to prevent the cooling air from accumulating below the window and flowing into the rest of the room. Anything goes to avoid cold feet ;)

47

Partly practical, the wall under the windows isn't useful for anything else. We had a house where the heaters were placed in the middle of the only empty walls, so nowhere you could put furniture, bookcases, etc. Before double glazing there would be a draft from the windows so the idea was to heat this incoming air by having a radiator immediately below the ...

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