Infrared heat lamps are widely used across a number of different industries, ranging from heating food in restaurants to providing therapeutic warmth for physical therapy treatments. All heat lamps emit invisible infrared radiation in order to generate heat but they are available in ruby or clear glass and we will explain what this means for each type of lamp below.

Core Difference: The Glass Envelope

Clear Infrared Heat Lamps

Clear heat lamps use a transparent quartz or hardened glass.  They are completely transparent which allows the light to pass through freely.  It emits a full spectrum of light and can be used for visible light or infrared lighting.  This type of lamp can be found in applications where a high heat output is needed but the presence of visible light is not a major concern. 

Ruby Infrared Heat Lamps

Ruby lamps are made from a quartz glass that is coated with a thin layer of red/ruby material, often containing metal oxides.  This coating is sometimes a gold colour to make it suitable for use in churches.  The aim of this coating is to diminish the brightness of the light that comes off of the filament while still allowing the infrared heat to come through.  

Key Operational Differences

The coating or lack thereof within the glass envelope of the infrared heat lamp directly impacts how it works and operates:

Heat Output and Efficiency

The heat output (infrared radiation) will be the same for comparable wattage lamps, regardless of their coating.  The difference is minuscule between lamps of the same wattage with a different coating and this will not be noticeable.

Application Suitability

Choosing which type of heat lamp is best between ruby and clear infrared lamp will depend on what you are using them for and where they are being used.

Ruby Lamps should be used when you require a heat lamp but need something that has a reduced glare.  An example of this would be where a lot of people might be present as the glare from clear lamps can cause discomfort, especially when someone is around one for an extended period of time.  This would be applicable to an outdoor patio heater or in a personal workspace such as a garage. 

Clear Lamps should be used when maximum visibility could be useful or would not cause a hindrance to what the room is being used for.  This could be in an industry setting where bright light would in fact be useful to help people focus on the job at hand.  Clear lamps have also been found to better for paint drying or curing materials as this process benefits from a full light spectrum output.