When researching the Different types of Infrared Heating for ourselves, we found that much of the information available was confusing and often conflicting.
The growing number of infrared heaters, lamps and suppliers in the marketplace isn't helping this situation and when we discovered existing lamps being given new names and then promoted as new technology by some retailers, some specialist retailers actually professing to have we thought it would be helpful to provide a "whistle blowing" list of the different types of infrared lamps that are currently available, so that we and our customers can all make more accurately educated decisions.
To be confident of the accuracy of our information we have asked industry expert and heating consultant Ian Lewin Bsc (Hons) to help us put together the following list of infrared lamps and some basic useful information for us.
Ian is a Science and Technology graduate and time-served electrician with over twenty years experience working in the infrared heating industry.
Basic Heating 101
In science heat is defined as the as the flow, or transfer of energy from a warm object to a cooler object.
There are three ways this transfer can occur:
- Convection - which is the transfer of energy through air or liquid, such as a conventional radiator in your room heating the air and causing it to circulate.
Conduction - through direct contact with a heat source, e.g. heating a needle in a candle flame and
- Radiation - energy transferred in the form of waves or particles that need no air, liquid or direct contact... Light from the Sun travels to Earth in this way (thankfully) and infrared is an "invisible part" of the Sun's light that we feel as heat. That heat is transferred to any surface the waves hit, but it's still very dark and cold in space as all that radiation in between the Sun and Earth is just travelling through!
- Your infrared heater does the same. A hot element, the "lamp" emits radiation, which travels to a surface (you) to warm it up; the air temperature in between is still the same as before you turned on the heater... Enough Science!(For more on this topic if you're interested, see "what is infrared").
Infrared Lamps & Lamps types - General
Different types of radiation are described using measurement of wavelength, or frequency. We also use the terms short wave, medium wave and long wave.
What's relevent when looking at infrared heaters, is the knowledge that short wave has the most energy, which means that short wave lamps are the hottest. In general, the short wave lamps all produce visible light in addition to heat and the various lamps types have coatings to filter out most of that visible light, typically except for Red.
Short wave infrared lamps operate at a very high temperature and heat up almost instantly (1 - 2 Seconds). They are extremely efficient and convert almost all of their input power into radiated heat.
Medium wave infrared lamps operate at a lower temperature, but their other properties i.e. speed and heat conversion efficiency are almost identical. They are a good choice of lamp if you're going to be close to it, for example siting under a restaurants parasol.
Long wave "infrared" lamps use a different technology that is significantly cooler, slower to heat up and less efficient than the above. They are useful for indoor applications, particularly where additional light would be an issue (see below).
Ruby sleeved and Ruby slim lamps
These are Short-wave lamps with red coloured glass to filter out all but the red end of the visible spectrum. Ruby sleeved and Ruby slim lamps were the industry standard for many years and they are still in use in many older fittings.
The lamps gives a 'ruby' red glow and are quite bright.
Gold coated lamps
Gold coated lamps are short-wave emitters that were developed by Philips as an alternative to ruby lamps.
Philips called the lamps HeLeN lamps before they were taken over by Dr Fisher. Gold coated lamps give much less glare than ruby lamps and commonly referred to as anti-glare.
They are Pink coloured to look at, but more importantly they are what's called "colour neutral" at a 3m distance. This means that surfaces at 3m away from the heat source are not tinged red – they look natural.
Ultra Low Glare Lamps
These are exactly the same as the above Gold coated lamps, but with an extra layer of coating, which meas they give out a little less visible light, which is used as a selling feature by some brands such as Tansun and Burda.
Looking at the lamps they are a slightly different to the standard gold lamps being a duller pink and they are still colour neutral at shorter distances.
Zero Light emitters
These are NOT short wave lamps they are LONG WAVE emitters.
These lamps have a Ceramic element – long heat-up time – only about 60% efficient as a radiant heat source due to convection losses. Generally they are used where visible light is not wanted – for example in photographic studios, or where a specific wavelength is required – e.g. vivariums and some pet heating. Ceramic lamps are widely used in the plastics processing industry as the absorbtion wavelengths are most compatible.
Absolutely no good at all for patio heating regardless of what you may read from websites. OK as local heating in well insulated areas. eg offices.
For example the softglow lamps you promote on your own website are good radiant heat source at closer distances – eg parasol heaters where heater is close to your head.
Looking at the lamp, they can be either a dull white (due to a frosted element), or a dull orange (true medium-wave, same as old fashioned bathroom heaters). As with the short-wave lamps, they are colour neutral at a distance.
Hope this explains it and Don't mind if you reference me as author
Please note that not all of the lamp types Ian describes above are available on our website, as the costs of stocking each type outweigh any real or significant benefits provided. However if you're looking for something specific that we don't have listed, please email us and we'll try to get it for you.