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Radiator BTU Calculator

BTU & Watt Calculator

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Why Do You Need Our Radiator BTU Calculator?

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 and 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 designer radiators or towel rails for a room – how do you know if the one you’ve got 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 radiator BTU calculator. Our BTU calculator 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 calculate BTU output of your room so you can find the most appropriate size radiator. Larger rooms are likely to require a greater number of radiators. Use the best BTU calculator to find out what BTU requirement and Watt output that will efficiently heat your room.

What Is a BTU?

BTU stands for British Thermal Units. 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.

BTU calculations account for the heat required to fill a room as well as the amount of heat loss.

How Does It Work?

Using our radiator BTU Calculator is pretty simple. The calculator works by factoring in the following aspects of your room:

  • From you inputting the dimensions of the room concerned (length, width and height in feet or metres), it’s able to automatically calculate the room’s cubic volume by multiplying these values together.
  • Our clever BTU calculator then throws into the mix further mathematical equations, which are based on the data you input for other factors – the type of room concerned (lounge / dining room, kitchen, bathroom or bedroom) and whether it features a north-facing wall, double glazed windows and French windows / patio doors (heat loss).
  • Finally, the BTU calculator will deliver the result, which comes in two parts – the first, a range between two values in BTUs; the second, a range between two values in watts. This then provides you with an accurate radiator sizing guide for the room, so you can be confident that, in choosing a radiator whose heat output lies within those ranges, it will be able to warm (and keep warm) the room both comfortably and affordably.

What If the Room Features More Than One Radiator?

You will only need to use the BTU 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.

Need Assistance?

If you require further assistance for assessing the required BTU of your room, don't hesitate to get in touch with Designer Radiators Direct today! Contact us by phone on 01257 442 911 or send an email with your enquiry to [email protected]. Alternatively, you can also fill out and submit your questions to us by using our online contact form.