Why Are Radiators Installed Under Windows?

For a lot of people, the placement of their radiator has never really been a point of concern. In fact, most probably think it doesn't matter, but there is a very good reason why you typically find radiators under windows, and the answer might just surprise you.

Why are radiators installed under windows?

There are a number of reasons why radiators are placed under windows; here are a few of the most commonly known ones.


In the times when central heating was still a new concept, the coldest area of any room was around the window. Victorian-era houses lacked the double and triple-glazing technology of today, so rooms then had significantly less insulation than they do now.

When households could afford a central heating system, it made logical sense to place the system near the coldest part of the room, near or beneath the window.


Radiator practicality

One of the more obvious reasons that radiators are placed under windows is that it is often unused space.

The area under most windows is generally quite limited in terms of practical uses, so people generally opt to place their radiators there. This does tend to vary, though, according to the architecture of your house.

Since radiators can take up a fair amount of space, placing them under the window frees up space on the other walls where you might want to position other furniture, such as a wardrobe or bookcase.

Some also theorise that being able to look out the window comfortably is a factor. Radiators discourage the placement of furniture, and furniture can impede those looking to admire the view.


The other reason is a little bit more scientific, as it is to do with the laws of thermodynamics. With traditional radiators, the hot air rises through the top. This air then interacts with the cold air from the window, further pushing warm air into the room.

If you were to place a radiator in the middle of the room, the heat wouldn't fill the room, and you would end up having cold spots. So, placing it on a nearby wall thus makes sense, and this is where both aspects of practicality and aesthetics come into play.


Radiator aesthetics

Most people with a radiator in their home are well aware of its presence, as they can be quite hard to miss. When radiators are placed on open and bare wall space, they become even more noticeable. This is why some people prefer to install their radiators under windows, as this area is generally seen as less noticeable than in the middle of a wall.

Should you put your radiator under the window?

Whether or not you place your radiator under a window largely depends on your house and how well-insulated it is.

For houses that are older or poorly insulated, placing a radiator under the window can be a good way of counteracting incoming cold air, but this approach is notoriously energy-sapping. If you haven't already, it might be worth investing in double-glazing or triple-glazing windows, as they do a good job making a room warmer due to the added layers of insulation.

With modern homes or, more specifically, ones built in the last twenty years, radiators can pretty much be installed anywhere. Due to improvements in glass insulation technology, radiators can be effective on any side of the room. This is why an increasing number of people these days are placing radiators according to what is practical or aesthetically appealing.

Ultimately, there is nothing wrong with placing your radiator under a window. Double glazing may have its benefits, but it is still not completely effective at preventing cold air from coming in. The space under the window works well as it is often free of furniture, and the radiator can better push the hot air around the room.

Where and how to place radiators

While you technically can install your radiator 'anywhere,' it is probably best to stick to solid wall space. Look for a part of the room that doesn't see too much traffic, as this will help to prevent injuries or unnecessary tampering, particularly if you have children or pets.

It is most advisable to install your radiator 3 to 4 centimetres away from the wall and at around 10 to 15 centimetres clear of the floor. If you're replacing a radiator, try to place the new one in the same location as the old one, as this makes installation far easier. Note that this could change slightly according to whether you have purchased a horizontal or vertical radiator.

Lastly, from an interior design perspective, you may or may not want the radiator to be the focal point of the room. Radiators are a very noticeable feature when you walk into a room, so it's important that you pick a radiator that aligns with the look you're going for.


What is a BTU rating?

BTUs or British Thermal Units are units that are used to measure the efficiency of a radiator. They represent the amount of energy it takes to heat around one pound of water. BTUs encompass factors such as room dimensions, window size, and wall material.

When purchasing a radiator, you should be able to see the BTU rating in the specifications section; if not, you can always use a BTU calculator.

Are vertical radiators better than horizontal ones?

Are vertical radiators better than horizontal ones

With the number of options available on the market, it can be difficult to choose between getting a vertical or horizontal radiator. To reassure you, always bear in mind that the two do not differ in terms of their function; they primarily vary because of how houses have different needs when it comes to space.

Vertical radiators are an ideal option for small rooms, and this is because horizontal radiators may simply take up too much space in a small room. Also, despite what many think, vertical radiators have an equal BTU heat output to horizontal ones, so they do the same job of warming cold air.

On the other hand, horizontal radiators more commonly come in flat panel options, which can save space while being slightly more efficient. Double panel radiators, for example, are more common in this orientation and can be run at lower powers to make cold air warm and keep heating bills at a minimum.

Fundamentally, both vertical and horizontal options bring an equal number of benefits to the table, so neither can really be seen as better than the other. The answer to this largely comes down to how well each shape can fit into and function within your home.

What type of radiator should I buy?

Buying a radiator is far from simple and straightforward, as there are many factors to consider. You first need to determine which room the radiator will be placed in because not all radiators are suitable for every room.

Once you've settled on the room that it'll be in, you can look at how you would like it to be fueled. Radiators work via electricity, and central heating ones use water, but there are also dual fuel options.

If, for some reason, you aren't able to find out the BTU rating of a radiator, then the actual size can be a good indicator of how effective it will be in your room of choice. As you may have guessed, larger radiators typically have greater heat output than smaller ones.

We recommend using our guide - What Size Radiator Do I Need? Or, check out our BTU calculator because working it out yourself can be complex.

You can lastly look at the material. Traditional radiators are generally made of cast iron, emit a good amount, and can be placed practically anywhere. However, the best modern radiators are made with aluminium which is better for heat transfer, is more energy-efficient, and is considered to be more stylish.

Shop the range of radiators at PlumbNation

Check out our vast range of radiators with styles and sizes to suit any space. From Flat Panel Radiators to Column Radiators and Designer Radiators, there is plenty of choice at PlumbNation.