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A gas fired infra-red heating system emulates the efficiency of the sun by generating radiant energy that is converted into heat when absorbed by objects in its path. Once the infra-red energy is absorbed by the floors, machinery, stock and people, it is then re-radiated to warm the surrounding air.

This method of heating an area allows the source of heat to begin at the floor level. This makes it one of the most efficient and effective methods to heat industrial areas whether well sheltered or open to air infiltration.

Types of Radiant Heater

There are two main types of Radiant Heater available.

Radiant Plaque Heaters

Example of a radiant plaque heater
Example of a radiant plaque heater

Radiant Plaque heaters are a compact, wall or roof mounted heater which do not need to be flued to the outside of the building. They are particularly suited for spot heating due to the high surface temperature of the emitter.

This type of heater typically is silent in operation, with electronic ignition and near instant heat due to a minimum of warm-up time.

They are typically used in older buildings where there is a lot of ventilation. Some example installation locations would include sports halls, churches, factories and workshops.


  • Heat outputs vary from 8.8kw to 44kw
  • High efficiency rating of 92%.
  • Instant heat - minimum warm up time required.
  • Quick heat loss recovery - not heating the air only the people &objects.
  • Roof or wall mounted - no valuable floor space required.

Radiant Tube Heaters

Example of a radiant tube heater
Example of a radiant tube heater

Radiant Tube Heaters are usually roof mounted and are typically flued to the outside of the building. This makes them ideal for newer buildings with a low air change rate.

This type of heater is more aesthetically pleasing than plaque heaters and this makes them ideal for commercial / retail applications. However, they are slightly more expensive to purchase and install. They also feature electronic ignition and very low noise levels.


  • Wide range available from 15kw to 44kw
  • Various lengths 9, 12, 15, 18 meters and optional U and L configurations available.
  • Instant heat - 3 to 4 minutes heat-up time.
  • Quick heat recovery - not trying to heat the air so heat is less susceptible to air changes.
  • Unique turbulator baffle - helps give an even heat temperature throughout the tube.
  • Venting options - air intake and exhaust flues available, providing for a fully room sealed system.
  • Roof or wall mounting options with no valuable floor space being taken up.

Radiant Plaque vs Radiant Tube - Quick Comparison

Radiant Plaque heaters are less expensive than radiant tube heaters to purchase and install. This type of heater tends to suit old buildings where there is plenty of ventilation. Radiant Plaque Heaters are also particularly suited for spot heating due to high surface temperature of emitter.

Radiant Tube Heaters tend to suit new buildings where air change rate are low and flues are required. Note: Radiant Tube Heaters can be installed without flues provided they meet the ventilation criteria of IS3212:1987. Radiant Tube Heaters are more aesthetically pleasing which is important in Commercial / Retail Applications.

Ventilation Requirements

A Ventilation rate of 35m3/hour per kW of installed capacity is required for un-vented gas appliances. This rate is essential for all plaque heaters and un-vented tube heaters.

Many older buildings will already have sufficient ventilation, however, new buildings should be checked against the above criteria. If the ventilation requirement cannot be met with natural ventilation then mechanical extraction may be used.

Design Strategy

A quick rule of thumb guide may be used to determing the heating requirement of an area. This gives a good approximation of what equipment you will need.

1. Calculate the floor area of the building (m2)

2. Multiply the floor area by one of the factors below to get the heat input needed in kW.


EXAMPLE: Building floor area 800 m2 x 8m High. Average insulation. Therefore, Heat Input = 800 x 0.2(from heat input factors table) = 160 kW

3. Determine the available mounting height for heaters from the table below.

4. Choose heater model according to the available mounting height allowing sufficient clearance over the heater. The larger the heater selected, the more economical the installation.

5. Work out the number of heaters needed dividing the total heat input needed by the heater capacity given in the table.


(Note, RV = Plaque, EDX/EHL = Tube)

EXAMPLE: For our building above we would select model RV 130 as it is the most suitable appliance for this application due to mounting height of 6 - 8.5 m. Each RV 130 provides 38.1 kW. Divide 160/38.1 = 4.19 heaters. Therefore, the number of heaters required would be 5 No RV 130 providing 5 x 38.1kW = 190.5kW.

Further information

Further information on our Radiant Plaque heaters, including pricing and technical data, is available at the following product group:

Further information on our Radiant Tube heaters, including pricing and technical data, is available at the following product group: