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British Thermal Units (BTU) measure heat output from radiators. Some rooms will need more heat, and others less; it depends on the size of the room, its function, and the number & type of windows in the room.
Depending on their functions, dimensions, wall materials and the number and size of their windows, some rooms in your home will require more heat than you might expect; others less. This then offers a challenge when choosing and purchasing a radiator or towel rail for a room – how do you know if the one you’ve in mind will deliver the correct amount of heat? How do you know if it’ll deliver too little or too much? How do you know if its heat output will be adequate and efficient?
The answer lies in finding out the ideal heat output for the room. This will be primarily measured in British thermal units (BTU), so the best way to work it out is by using what’s known as a BTU calculator. It will help to narrow down your radiator choice based on what’s truly going to be an effective and efficient radiator for the space; an appropriate model for the room in which you intend to install it.
When purchasing a radiator from Designer Radiators Direct, it's best to measure the BTU of your room so you can find the most appropriate radiator for it. Larger rooms are likely to require a greater number of radiators. Use our BTU calculator to find out what BTU and Watt output will efficiently heat your room.
Strictly speaking, a British thermal unit is a calculation of the energy needed to heat 1lb of water at 39-40°F (3.8-4.4°C). In energy terms, this roughly equates to 1.055 kilojoules (kJ); in layman’s terms, it’s more or less the amount of energy it takes to burn a wooden match.
To use our BTU Radiator Calculator opposite is pretty simple, don’t worry; but to break it down, here’s what the process is all about:
You will only need to use the calculator once for a room – the result it produces is for the heat output of the entire room. So, if you’re planning on installing or replacing more than one radiator, the figure will be for the heat output of all the room’s radiators combined.
Be aware then that, if you’re new to purchasing radiators and having them installed, should you be dealing with a fairly copious space – such as a large lounge or hallway – you may need two, three or more radiators evenly spread throughout the room to ensure there’s adequate heat. In this scenario, you should simply divide the calculator’s result between the number of radiators you’re intending to install or replace in the room.