The 5 most common questions about BTU

1. What does BTU mean?

BTU stands for British Thermal Units and this is the most common way energy and heat output is measured in the UK.

1 BTU = The amount of heat needed to raise the temperature of 1 pound (0.45kg) of water by 1° Fahrenheit (0.56° Celsius).

2. Why is BTU important?

British Thermal Units are important because they are the gauge by which you can measure how adequately a radiator will heat your room.

When searching for new radiators (or air conditioning units), you will see their energy outputs displayed in BTUs.

To work out how many BTUs are required to comfortably heat each room in your home, please use our simple Heating Calculator.

3. How does BTU work?

1 BTU is the amount of heat needed to raise the temperature of 1 pound (0.45kg) of water by 1° Fahrenheit (0.56° Celsius).

Your radiator will have an associated figure that shows how many BTUs per hour your radiator is capable of emitting.

Using our heating calculator, you can work out how many BTUs each room in your house is required to get the room up to a comfortable temperature.

You can then choose suitable radiators that are capable of providing the right amount of heat.

4. Is BTU per hour?

Normally, when you see the BTU of a radiator, it refers to the BTUs per hr (BTU/hr) that are used to heat the room.

Please consult our Heating Calculator to establish what BTUs per hour your radiator should emit, so that your room is heated properly.

5. What BTU should I get?

You need to get a radiator that emits enough BTUs to heat your room sufficiently. Use our heating calculator to establish what you need in each of your rooms and choose a suitable radiator(s) accordingly.

The amount of surface area on a radiator will affect how much heat (BTUs) the radiator can emit. For example, a double panelled convector radiator will emit more heat (BTUs) than a heated towel rail of the same dimension.

This is because the surface area of the radiator is greater than the heated towel rail and more heat can be radiated as a result.

If you have a small amount of space in your room and can't find a suitable horizontal radiator with enough BTUs to heat the room, consider a vertical radiator that can make better use of upward space.

Use our Heating Calculator


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