It’s strange how some people embrace cutting-edge products such as the latest smart phones and satnav but then prefer the 100-year-old technology of filament lamps – but never paper maps!
I suppose the appeal of these lamps is their cosy appearance. They can make a bar or café seem warm and comforting or ‘hygge’ as we say nowadays. The reason for this is the lamps’ lower colour temperature, CCT, often 2700K but some are as low as 2200K. These have a much ‘warmer’ appearance than the more usual 3000K – 4000K used in interiors.
Historically, the carbon and later, tungsten, filaments were run at low temperatures to improve their life. Higher filament temperatures made them more efficient in terms of lm/W and gave a whiter light but this technique slashed the lifetime.
These new retro style lamps use tiny blue LEDs mounted on thin glass. This is then covered with a uniform layer of phosphor to achieve white light. It is worth mentioning, however, that the efficacy and life of these lamps is generally lower than the mid- and high-power LEDs usually found in conventional sources.
Don’t forget that lampshades were introduced not long after the introduction of the incandescent lamp and this brings me to an important aspect of these retro style lamps. A powerful bare filament whether it’s tungsten or LED can be very glaring.
If you don’t want to use a lampshade, you have two options. One solution is to use more, lower output, lamps. Generally, lower wattage lamps emit fewer lumens per length of filament and are thus less intense to look at.
Interestingly, one manufacturer says that a high lumen output from a warm 2200K source just doesn’t look right. There may be something in this – we naturally associate warm sources such as candles, gas lamps and campfires with low levels of illumination.
Another solution is to dim the lamps. Not all brands of this type of lamp are dimmable so it’s something to look for. You should always check the compatibility of the lamp with your dimmer. My recommendation is to use dimmable versions.
One slightly disappointing aspect of many of these lamps is that they only have a power factor of 0.5. For home use where you are billed in watts, this may not matter but for commercial properties billed in Volt Amps (VA), these lamps consume a lot more than they appear.
Lastly, look at the rated life of the lamp. 15,000 hours is typical but some are as low as 5,000 hours. Mind you, even that is at least twice as long as a conventional filament lamp.
Enigma has a huge range of this style of lamp. All are dimmable and 2200K. The difference is in the shape of the bulb and the filament shape. There are also versions with copper, gold and silver crowns.
The version we looked at is the 8W, 600 lm, 125 mm clear globe. It has eight straight filaments. What sets this apart from other similar lamps is the colour rendering, CRI 90, so the 2200K lamp achieves a nice, warm appearance whilst still giving excellent colour rendering.
Factorylux Large Globe
This is a 125 mm diameter clear globe with eight straight filaments. It is comfortable to look at and Factorylux says that the light output has deliberately been kept fairly low to minimise glare.
However, it is also dimmable. What distinguishes this lamp from others is that it has a rated life of 25,000 hours and colour rendering, CRI, of 90+.
The clear bulb coupled with the filament support wires produces a striking bicycle wheel spokes effect on the ceiling/floor.
If you do want a high output lamp, Factorylux has a 700 lm version but this is frosted and has a slightly lower CRI.
Integral Sunset Vintage
This is different in several ways from the usual 125mm globe. It has tinted glass and with the warm LED filaments has a CCT of just 1800K. It looks really warm and comfortable.
Another difference is that it has just two filaments.
The light output is 170 lm and consumes just 2.5W so it is not so intense or glaring as some higher power ones on the market.
You could achieve a good effect in a space by using lots of these rather than a few big ones.
If you want dimming ability, Integral have a similar 5W, 380 lm version.
Kosnic KTC Antique Filament
Kosnic has a wide range of filament type lamps and we chose this helix-shaped one simply because it looked different from many others on the market.
The 125 mm diameter globe has an inner golden-coloured finish that gives the lamp a warm 2200K colour appearance. There is hardly any shadowing from the lamp so it emits a soft light all around.
There is a comprehensive datasheet which, very usefully, includes a list of compatible dimmers. It’s a nice lamp.
The 7W radio-valve shape we tested is part of the companyh’s current range which is soon to be upgraded. For example, some of the new lamps deliver over 120 lm/W and have a CRI of 90.
The series also includes A60/GLS shaped bulbs in wattages from 8 to 11W.
This particular lamp has a clear bulb and four filaments. It’s one of the most efficient lamps in terms of lm/W. As such, it produces a lot of light from a small package.
Sylvania Lighting ToLEDo GLS
This is a budget range of LED filament lamps designed as straightforward replacements for a standard GLS lamp (sometimes known as A60 bulbs). There are four straight filaments in the clear bulb and range from 4.5W (with an output of 470 lm) to 11W (1,521 lm).
In my opinion, the lower wattage versions are preferable because they are easier on the eye; the 11W really needs a shade.
They are non-dimmable and, like many others, have a power factor of 0.5. One advantage of these lamps is that they deliver a lot more lumens per watt than many of their competitors.
The datasheet includes a coloured diagram showing the strength of colours across the spectrum. You might know this as the Gamut Area Index.