Heating your home isn’t as simple as choosing the designer radiators you really like and assuming they’ll do the job – you need to be certain that each radiator is fit for purpose. There’s no point buying a radiator based on looks if it’s not going to provide enough heat, always leaving the room feeling too cold.

Therefore, once you’ve decided on the perfect radiator that will complement the look of every room, you need to make sure the radiator is the right one to heat the room properly. In the UK, this is done by calculating the BTU needs of the room in order to determine what size of radiator is the best one.

What is BTU?

BTU stands for British Thermal Unit. It’s the standard heat measurement used in the UK, and shows the amount of energy it takes to heat one pound of water (roughly the equivalent of a pint) by one degree Fahrenheit.

Why it is so important to know the exact BTU

By knowing how much heat each radiator will emit, you can calculate the wattage output needed from each radiator in order to efficiently heat each room. If you install a radiator that’s too small for the room, the energy required to heat the room will be greater than the radiator can produce, meaning the room will always be too cold. If your room is on the cold side of the house, draughty and poorly insulated, a larger radiator will be required to heat it to the same standard as a similar sized room that is facing south, has efficiently insulated cavity walls and triple glazing. In larger rooms, you may even need more than one radiator.

If you install a radiator that’s too big for the room, you’ll be producing too much heat which means you’ll be wasting energy.

BTU calculator

While there is a mathematical way of calculating the BTU needs of every room, it’s a lot easier to complete our online heat calculator to find out the heat output needed to create a comfortable temperature for each room in your house. Before you start, it will be useful to make a note of room dimensions, window sizes and the type of home insulation. The calculator will tell you the wattage requirement per room, giving you an idea of the radiator sizes you’ll need. This will be an enormous help with your budget calculations which, in turn, will dictate your radiator choices.

Other factors to take into account

There are many features in a room that will affect the amount of heat needed, and the trick to getting suitable radiators is to take them into account. They include:

  • the size of the room
  • which floor it’s on
  • the number and size of windows in the room
  • how many external walls there are
  • how well insulated the room is which indicates the amount of heat loss there may be)
  • which direction the room is facing
  • what the room is being used for in order to calculate how much heat is needed (bedroom, living room, hall etc). For example, the hallway isn’t a room in which people spend much time, so its heating needs are less than the living room where you’ll be spending a lot of time
  • is there an additional heating source in the room, e.g. an oven and hob in the kitchen, a fireplace in the living room, or a hot water tank in one of the bedrooms

Once you’ve calculated your wattage

Then comes the fun bit of choosing your new designer radiators. Our full range of radiators can be found on the website. All our radiators come with a BTU rating so you can work out the size you need for each room. On each product page, select the length, height and depth (where indicated) of the radiator; at the bottom of the screen you’ll see the Heat Output in Watts. You can then adjust the length and height until you find the correct size for the room it’s intended for, along with the total price.

Our advice is to then visit one of our showrooms to make sure you’ve made the right choice of radiator design and size. Each showroom has examples of most of the models we sell, along with the colour charts and examples of finishes. Our specialist staff will also go through your heat calculations to double check you’re ordering the correct sized radiator so you don’t make any mistakes that will prove costly in terms of time and money. They’ll also be happy to answer any questions you might have about heating your home.