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Why Are Radiators Put Under Windows?

Summary of topics:

Have you ever wondered why radiators are so often placed beneath a window? Is there a reason behind the placement or is it simply a random design choice during the construction of a property? You’re certainly not the first person to ask.

Keep reading to find out why radiators were historically placed under windows and why it may not matter so much within modern properties.

The history of radiators under windows

There is, in fact, a good reason as to why radiators are placed under windows. Before double-glazing was introduced and windows were mainly single-glazed, the window was the coldest area of a room. This is because the heat in the room is easily lost through the thin glass which creates a cold area close to the window surface.

By placing a radiator directly underneath the window, hot air is produced and released, which then rises to hit the cold air from the window. This creates a warm curtain of air over the window surface.

These days, most windows are double or triple-glazed, heat isn’t lost as quickly through these types of window and the area close to the window surface stays much warmer. Therefore, it’s not as common to see radiators under windows in new builds or modern homes as there can be more flexibility here.

Where is the best place to position a radiator?

Here are some key points to consider when deciding where to position a radiator:

Coldest part of the room

Your window may not be the coldest part of the room. For example, it could be a wall or a corner of a room. In this case it may be worth placing a radiator in a cool area to counter act the cold area close to the wall in a similar way to a window. Again, this will result in more effective heating. Heat reflecting materials are available which can be placed behind radiators, this reduces the heat being lost directly through the wall behind it allowing more heat into the room. It is also very important to consider any drafts, heat in a draughty room is lost very quickly.

Furniture

You’ll need to think about where you will be positioning your furniture, as this will impact the efficiency of your radiator. For example, make sure not to block a radiator with a sofa or the radiator will not be able to warm the room successfully. In fact, this is also one more reason why radiators are often still placed underneath a window as this space is most likely to be left empty.

Design

In the modern day, radiators are not only functional, but can also act as a focal design point of a room. There are numerous shapes and sizes to choose from, whether it is vertical or horizontal, panelled or slimline.

The look and design of the radiator will impact the placement, but it is strongly recommended to ensure your heating system can cope with the design before going ahead.

Should you tuck curtains behind radiators?

If your radiator sits beneath a window, you may feel inclined to tuck your curtains behind the heater so as to not trap any hot air. However, many modern radiators use the back panels as part of their heat output, so this would restrict the flow of warm air into the room.

We recommend opting for short curtains which would eliminate the issue or, if longer curtains are preferred, keeping them to the side of the radiator as much as possible.

Summary

  • Radiators used to be placed under windows to help the flow of warm air around the room as it hits the cold air from the window
  • Modern windows are double-glazed, so modern properties can be flexible within their radiator placement
  • It is not recommended to tuck curtains behind radiators as this could restrict the flow of warm air