Industrial Space Heater

What is a space heater?

A space heater is an individual device usually used to heat a single, small area or space, unlike a central heating system which is used to heat a number of rooms. Portable space heaters can create heat by either burning a fuel such as gas or diesel, or using an electrical supply. Electric space heaters are generally considered to be better and safer as there are no unpleasant fumes, no need for a permanent exhaust, additional fuels, or naked flames, just plug them into a suitable supply and they’re ready to go.

I’ve heard the term ‘space heater’. What’s the difference between a portable electric heater and a space heater? Nothing. Portable electric heaters are a type of space heater.

How to calculate your space heater requirements:

The first port of call when choosing a portable space heater for an area is to size the area. The size is chosen in three dimensions, so must include length, width and height. The area being heated must also be enclosed. The calculation for heat requirement is done in cubic metres so you require the length x width x height in metres. If you only have the dimensions in feet, then these will need to be multiplied by 0.3048 each in turn to give dimensions in metres, then those figures must be calculated to get the volume in cubic metres.

Once you have the volume in cubic metres, you need to decide on a temperature rise. Choosing a required temperature doesn’t always give an accurate calculation, as the amount of heat required is based on the insulation value and temperature rise – it will obviously take less heat energy to raise a room from 15 deg C to 20 deg C than it would to raise a rom from freezing (0 deg C) to 10 deg C.

Having chosen a temperature rise, the final part of the calculation is the K value or insulation index. If the room is well insulated, on a similar level to a house, then a K value of 1.2 is correct. If it’s insulated, but less so, like a porta-cabin, caravan, or workshop then 2.2 is the correct K value. For draughty workshops, open warehouses and uninsulated buildings then use 3.0.

If there is no insulation at all, for example a marquee or a building site, then the value 4.0 should be used for K value.

So the full equation is (length x width x height) x temperature rise in deg C x 4 x K Value = BTU/hr required.

The BTU/hr required can be divided by 3412 to give kW/hr.

So for example a 30ft x 60ft marquee with a 4 m high ceiling, requiring to be at 22 deg C when it’s -5 deg C outside:-

30 x 0.3048 = 9.144 ( 30ft in Metres.) x 2 = 18.288 (60ft in Metres.)

9.144 x 18.288 x 4 = 668.90188 (Volume in cubic metres.)

668.90188 x 27 (total deg C temperature rise.) = 18060.35

18060.35 x 4 = 72241.4 x 4.0 (K value for Marquee (uninsulated)) = 288,965.6 BTU/hr

288,965.6 BTU/hr divided by 3412 = 84.690973 kW/hr output.

Please note that although these figures are a very good place to start and an industry standard method used for calculation of heat load, they should be treated as indicative rather than absolute. They are there to give you an idea as to how much heat you might require but due to the amount of variables involved in accurately specifying heat loads for each separate application then we cannot guarantee they will be 100% accurate.

Conversion Table

MetresFeetDeg CDeg FKW/hBTU/h
1 Metrex3.28084xxxx
1 Foot0.3048xxxxx
1 Deg Cxxx33xx
1 Deg Fxx-17xxx
1 kW/hxxxxx3412
1 BTU/Hxxxx0.000293x

Why Broughton EAP

At Broughton EAP, we have been in the industrial heating business for over 30 years. We have provided solutions for a host of prestigious big names including end users such as the Bugatti Owners Club and the Ministry of Defence and climate control specialists Andrews Sykes, ICS Cool Energy and Carrier Rental. We’ve designed, manufactured and supplied industrial space heaters to provide warmth everywhere from small industrial units all the way up t huge aircraft hangars, offices to mines and everywhere in-between.Our equipment is built to last, fully serviceable with full spare parts availability and comes backed up with a two year warranty.

Details on our full range of portable HVAC equipment including industrial space heaters can be found at Should you wish to discuss your requirements or need help in selecting the best possible and most cost-effective system for your specific application then please do not hesitate to contact us on either +44(0)1527 830610 or by sending a message to