Radiant tube heaters are compact, self-contained direct heating devices. They can be used to heat factories, warehouses, foundries, gymnasiums, loading docks, race track stands, arena bleachers, outdoor restaurants, swimming pool surrounds and many other areas. Radiant tube heaters can also be used for snow melting and de-icing, as well as in car washes and other hostile environments.   The sun in a tube Radiant tube heaters heat buildings in essentially the same manner that the sun heats the earth – with infra-red energy.   Infra-red energy is a form of electromagnetic (EM) radiation. It makes up a portion of the electromagnetic spectrum and has wavelengths close to the wavelengths of visible light, but infra-red energy cannot be seen by the human eye. Infra-red energy, like all EM radiation, travels in straight lines at the speed of light.   Infra-red energy is commonly thought of as heat but infra-red energy only creates heat when it is absorbed by things with mass. For example, infra-red energy generated by the sun travels through space relatively unaffected until it strikes the earth's surface where it is transformed into heat energy. The heat energy is stored in the ground and is given off to the air. Imagine yourself walking along a sandy beach on a very hot day. The sand is very hot on your feet even though the air temperature is considerably cooler. That is because the sand, which has a lot a mass, readily absorbs the infra-red energy from the sun, while the air, which has very little mass, does not. The more mass something has the more infra-red energy it can absorb and the more heat it can then give off.

Radiant tube heaters radiate infra-red energy which is absorbed by things with mass and whose surfaces are not highly reflective, such as floors and people. An intermediate transfer medium such as air or water is not needed, nor are fans or pumps. As personnel, floors and objects in the primary radiation pattern are warmed by the infra-red energy, they tend to radiate heat to the surroundings by conduction and convection.

How radiant tube heaters work In a radiant tube heater a gas burner is connected to one end of a steel tube combustion chamber. Hot combustion gases are moved through the tube by a high-energy vacuum exhaust system. Combustion contaminants are exhausted at the other end of the tube to the outside. When combustion takes place inside the combustion chamber, the tube radiates infra-red energy. A highly polished aluminum reflector directs the infra-red rays to the target area.

The illustration at left shows a simplified cross-section of a radiant tube heater. The steel tube (yellow-orange circle) radiates infra-red rays (red lines) 360º around the tube. A carefully designed reflector (black line) ensures all the rays are directed toward the target area.

Advantages over forced air heating systems   Lower Fuel Costs When conventional forced air heaters are replaced with radiant tube heaters it is commonplace to achieve fuel savings of 30% - 50%. Fuel savings of greater than 50% are not uncommon.   Less Heat Loss Because heat is generated and maintained at and near floor level, ceiling temperatures are lower, reducing heat loss through the roof.   Fast Heat Fast heating-up time means the heat does not need to be turned on very far in advance of employees showing up for work.   Greater Comfort at Lower Temperatures Because the heat is given off primarily from the floor and other surfaces and not the air, worker comfort can be maintained at lower thermostat settings.   Target Heating When several radiant tube heaters are employed in a given space such as a factory or warehouse, the heat can be efficiently delivered only to specific areas, such as those occupied by employees, by turning on only the radiant tube heaters for those areas. This saves the cost of heating unoccupied parts of the building.   Out-of-the-way Installation Radiant tube heaters are installed overhead and out of the way. Their low profiles take up less space than conventional heating equipment.   Faster Heat Recovery As radiant tube heaters do not rely on heated air to deliver heat, heat lost through an opened door is recovered more quickly than with conventional forced air heating systems.   Unobtrusive Operation With no fans, radiant tube heaters are quieter than conventional forced air systems and because they do not move air they do not stir up dust.   back to PilotLight online