Garage heating

Machine Mart's Buyers Guide To Heating

Keeping your garage or workshop warm is not just for comfort, it’s a matter of safety too. It is much more difficult to use machines and tools when your hands are cold and the risk of injury rises as the temperature falls.

There are several ways to heat your workspace, with a choice of fuels.

  • Electricity
  • Bottled Gas – Propane/Butane/LPG
  • Oil –Paraffin/Diesel/Waste oil
  • Solid fuel - Wood/coal/Biomass

Each fuel has its pros and cons and consideration should particularly be given to the power supply, ventilation and size of your premises. 

Are very clean and convenient and there is a wide choice of electric heaters available with heat output from a few hundred watts up to 15kW if you have a suitable power supply. Care has to be exercised with any electric appliance to keep it away from water and/or flammable substances. 

A normal domestic, 13Amp single phase power supply is capable of powering up-to a 3kW heater. However you also need to think about any other equipment you may need to operate, the length and core size of the supply cable. 

In commercial premises a 3 phase supply will be capable of a far greater supply, enabling you to use more powerful heaters. 

CONVECTOR HEATERS – This type of heater has an element which heats the air surrounding it. As warm air is lighter than cold air, the heated air rises and is replaced by cooler air, creating a current. As there are no moving parts, this is an almost silent type of heater. They are ideal for heating an enclosed space and have a lower risk of fire hazard than fan or radiant heater and may be left unattended.

FAN HEATERS - This is basically a convection heater which includes an electric fan to speed up the airflow. This makes the heating process much faster, but is relatively noisy, also due to the higher temperatures involved fan heaters should not be left unattended. Machine Mart sells both domestic and industrial versions. 

RADIATORS and RADIANT HEATERS – Directly heat items around them by radiated heat. Some also heat the air in a room by convection. However, due to their higher surface temperature, care should be taken with furnishings nearby. There are both domestic and industrial models available. These heaters operate silently. 

QUARTZ HALOGEN – These heaters provide instant heat and only heat the objects placed in front of them, not the surrounding air. This makes them ideal in situations where there are constant draughts and they are also silent. 

Industrial space heaters can be fuelled by Paraffin and Diesel (Not red) or Propane gas. They use an electric fan to blow the heat created by burning the fuel into the environment. They are ideal for heating large spaces for example warehouses, factories and garages. With heat output from 35,000 to 344,000 Btu. All require mains electricity to power the fan but only at a relatively low wattage. 110 and 230 volt models are available. As with electric heaters, care has to be exercised with any electric appliance to keep it away from water and/or flammable substances. 

There are a variety of cast iron stoves to suit domestic and commercial premises. The advantages of this method of heating are – No reliance on a mains supply of gas or electricity. They may be used to burn coal or wood, including waste wood and off-cuts and. They can add an attractive traditional feature to a room. The majority of them may also be used for boiling a kettle or cooking. There are models suitable for use in boats, houses, pubs restaurants, workshops, studios and many other places. Heat outputs vary from 10,000 to 61,000+ Btu. Because Solid fuel stoves do not require an electric supply, they may safely be used where water may be present, but you should still be careful where flammable substances are present. 

The output of a heater is measured in Watts (W) and kiloWatts (kW) for electric heaters and British Thermal Units (Btu) for all the others. 1 Watt is approximately 3.4 Btu. There are 3 steps to calculate the power of heater you need, you should consider:

1. The volume of the space to be heated,
2. The rise in temperature required.
3. How well insulated the space is.

The volume of the space is calculated by the following formula - width x length x height. So, for example a single garage 3m wide x 5m long x 2.5m high will have a volume of 37.5 cubic meters.

This figure should be multiplied by the required rise in temperature, in °Celsius.

And then multiplied again by the figure below, depending on the level of insulation in the building. This figure is as follows- 
No Insulation x 3.5, Light Insulation x 2.5, Medium Insulation x 1.5, Heavy Insulation x 0.5
Then to return a result in Btu, multiply this by 4
Therefore, in the case the single garage mentioned above, with a temperature rise of 10°C and it has no insulation, the calculation would be:
37.5 x 10 x 3.5 x 4 = 5250 this gives an answer in Btu. 
(To convert this to kiloWatts divide 5250Btu by 3412 = 1.5kW)

So now you know how much heating power is required, you should turn your attention to the available power source.