How many radiators do I need in a room?

When it comes to designing your perfect living space, deciding how many designer radiators you need in a room to heat it efficiently is a key consideration.


When it comes to designing your perfect living space, deciding how many designer radiators you need in a room to heat it efficiently is a key consideration.

Before deciding on where to position them and installing your new radiators, you’ll need to establish how much heat output you’ll need to keep things nice and toasty. The heating output of a designer radiator is measured in British Thermal Units (BTU). Obviously, the larger your room is, the higher its demand for heat will be. However, other factors, like where to position your designer radiators and how many radiators you need in a room are also things you’ll need to consider.

The style of designer radiator you choose, along with flooring, insulation, room layout and wall space may also impact the BTU output you need. Manually working out the number of BTUs you might need can be quite a complex and challenging calculation to make, thanks to the different factors listed above. Here are a few top tips to help you get the right information:


How big is your space?

In order to work out how many radiators you need in a room, the first thing you’ll need to do is establish the volume of the space you want to heat. This quick calculation can be done by multiplying the length of your room, in metres, by its width and height, as follows: L (m) x W (m) x H (m) = volume (m³). As a general rule of thumb, have one radiator for every 5m³ of space you need to heat.


How many BTUs do you need?

Once you have established the volume of the room you want to install your new designer radiators in, you’ll need to work out the standard level of heating output, in BTU, required to heat a room of that size. In general, this can be done by multiplying the volume (m³) of the room by 153, as follows: Room volume (m3) x 153 = BTU output required.


What else do I need to consider?

Once you know how what the required BTU output is, there are a number of other factors to consider which can either increase or decrease the output rating of the designer radiators you require. While it’s not an exhaustive list, the following factors should be considered:

  • Solid floor – decrease total BTU by 10%
  • Uninsulated cavity walls – increase by 10%
  • Foam-filled cavity walls – decrease by 20%
  •  Upstairs bedrooms – decrease by 25%
  • Double glazing – decrease by 5%
  • Two outside walls (ie rooms on a corner of your house) – increase by 15%
  • Three outside walls – increase by 40%
  • Northern-facing outside wall(s) – increase by 10%
  • No loft insulation – increase by 15%
  • High ceiling (3m+) – increase by 20%


How many radiators do I need in a room?

As a general rule the larger the radiator, the larger the BTU rating. However, simply choosing the biggest designer radiator may not be the best option. Sometimes, two (or more) smaller radiators can be more efficient than one big one.


Make it easy on yourself

If maths isn’t your strong point, there is an easier way of working out your heating requirements. By using our online Designer Radiator BTU calculator, you can quickly and easily work out how much output you require and how many radiators you need in a room.

Our BTU calculator should be used for guidance only, but it will give you an accurate estimate and a good starting point from which to choose the right size of designer radiator for your room.


Choose from our wide range of designer radiators

As the above guide shows, working out how many radiators you need for a room is easy. The hard part comes when you’ve got to choose which designer radiators will help you create the perfect space.  With so many different sizes and shapes to choose from, it’s hard to know where to start, but that’s where we can help. Whether you’re looking for vertical designer radiators to create a real focal point to any wall, contemporary designer radiators that complement your design or colour scheme, or bespoke glass designer radiators that inject a bit of your personality into the room, we have the perfect one for you.

So, why not pay our Designer Radiator Showroom, in Ashby de la Zouch, a visit for more inspiration and designer radiator ideas. With over 4,000 designer radiators in stock - all at factory direct prices with fast, free UK delivery - you're sure to find whatever you're looking for. Alternatively, give us a call on 01530 564 122 or email us, we’ll be happy to help.

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