The materials and processes behind the product: Kvisten shines a light on low carbon choices

We recently welcomed a new product to our range?- Kvisten. This innovative wooden light fixture, partly made from repurposed television sets, is capturing the attention of eco-conscious specifiers.

A unique pendant luminaire that offers both energy efficiency and light quality, Kvisten is crafted from 77 per cent recycled or renewable materials. Having been asked questions like, “why wood?” and “how did you come up with the idea of using repurposed TV reflectors?” we wanted to share more about the inspiration, materials and development processes which led to the creation of Kvisten.

Here, Cecilia Niva – Product and Application Manager at 法格赫照明 –?reveals all. ?

Kvisten's body is entirely made of wood. What type of wood, and why?

Our goal as a company is for all our products to consist of at least 80 per cent renewable and recycled materials before 2030. So, with Kvisten, we wanted to really consider the materials we used in order to create a luminaire with low CO2 emissions and minimal climate footprint.

For Kvisten’s housing we settled on pine plywood with a birch veneer. The plywood is cross-laminated, to give strength in all directions, and we added a birch veneer to give a beautiful finish whilst also reinforcing the structural rigidity.

An internal researcher explored whether we could find a more sustainable material than wood. Our expectations were confirmed that currently, it would be difficult, if sourced ethically. This is something we continue to debate though, considering things like biodiversity, wood’s renewability and the fact that all forests consume CO2 while growing.

Most of the wood we use is 100% FSC certified, with a few small details from poplar wood that is 70% PEFC certified. But, we’ll never stop questioning whether what we’re creating is as good as it can be.

Using wood also gives Kvisten a lovely Scandi- feel and brings beautiful natural materials indoors. This is a hugely popular style and allows people to visually communicate their commitment to more sustainable spaces, compared to other material and product types, such as recessed fittings.?

The reflectors in Kvisten are taken from TV sets that have reached the end of their life. Tell us more about this, and how you settled on repurposed TV reflectors as a solution.

The inspiration behind using TV sets came from a familiar source - our flat panels which use a similar technique and the same material, white PET plastic, which provides 98% reflectivity. TV manufacturers also require maximum reflectivity for best uniformity and thinner screens, so we realised that repurposed reflectors would be ideal for Kvisten. The reflectors also don’t need any processing, except for cutting into shape.

We have an existing partnership with Stena Recycling, to ensure our waste is given new life. Around 1% of the total waste is treated as landfill, and as much as 85% is recycled into new useful materials. The rest of our waste is converted into energy that helps to heat households and other buildings. With Kvisten, we wanted to find a material which can be directly up-cycled, with no real limitations on how many we can source moving forward. Having decided on the material and worked with Stena Recycling to arrange sourcing, we experimented with positioning it in every possible configuration to ensure we got the highest level of reflection and as a result, efficiency.?

Is the efficiency of the reflectors key to the energy efficiency of the overall units?

It’s an important part of the outcome, but also, when we are creating a high-efficiency luminaire like Kvisten, we spend as much time as we can fine-tuning the design. With the reflectors, for example, we tried them under the LEDs, and then above, with holes cut, and we tried different options with the end caps too. With the reflectors, we have created a light chamber, pushing almost all the light out from the luminaire. And this high efficiency is the start of a positive spiral – we can run the diodes more gently which makes the luminaire even more efficient.

Thanks to the design of Kvisten, we’ve also eliminated the need for an LED safety sheet. It’s a standard in the industry that you have to protect installers and anyone working with the fitting from voltage and heat, so LEDs often need a clear safety cover to prevent them being touched. With Kvisten, the louvre itself acts as the protection, and it requires a tool to remove the optic. This doubles as a safety cover, removing the need for an additional cover and further improving the efficiency as the light has to travel through fewer layers of plastic.

Kvisten uses Fagerhult’s Delta as a louvre. But, it’s a new version of Delta, which uses half as much plastic as previous versions, or micro-prism louvres generally. How did you manage that?

If we look at the prisms used, they are a great deal smaller than those that would normally be described as micro-prisms. Traditionally, micro-prism means something which has a size of perhaps 3 to 3.5 mm. That’s measuring the thickness of the prism itself and also a sheet of plastic underneath. With Kvisten, we’re able to offer a solution with a thickness of 1.5 mm - less than half the thickness of standard microprisms - and therefore less material, less plastic.

This also changes the appearance of the louvre - the prisms are practically invisible. I would say it’s more reminiscent of our Opal louvre. So, you have this very smooth, clean appearance, combined with the degree of control and the optical properties of a micro-prism solution like Delta.

So, you cut down on plastic. But, the plastic you do use in the louvre is virgin plastic, not recycled. Why is this?

This was a deliberate decision. Virgin plastic is clearer and therefore the luminaire has a higher efficiency. Kvisten produces 144 lumens per watt, which is very high for an LED luminaire. If we had used recycled plastic, we would have lost perhaps 4% to 5% efficiency. So, we might have created the illusion of more sustainability by using recycled plastic, but customers would have to use more energy to light their space, with all the implications of that.

What other measures did you take in relation to sustainability and materials?

We wanted to use as little material as possible, and also as few different materials as possible. As wood is a great material in terms of sustainability, we managed to create a design which not only uses it for the housing, but also the mounting sheet, the driver lid, the sensor lid, the wire attachments, the wedge that holds the housing together and finally also the wooden plug. Kvisten truly is a wooden luminaire. The packaging is also entirely recycled and completely plastic-free.

For the form of the house we replicated the clean line aesthetic of Notor. Kvisten started at 65mm but grew, reflecting the demands of the UK market for direct light output. We made a conscious decision to size Kvisten for maximum efficiency (144 lm/w) and best light quality and glare control. With this in mind, we tapered the edges of the housing to help increase the optical area.

So, all in all, we found 1% efficiency gain here, and 1% there, and it all adds up. During this project, it became clear that when many people with different expertise are challenged to think in new ways, then really big things can happen. Many small changes have combined to make a huge difference to the result.

The wires used are another area of change. Tell us more about “wires without worries”.

Every component of Kvisten is considered, including suspensions. Nickel plating of metal luminaire components is commonplace, but nobody really knew why. Traditionally, wire locks are nickel plated, and they also contain a small but significant amount of lead. With Kvisten, we chose to use brass. We eliminated the nickel, eliminated the lead, and we love the look of brass.?

When using recycled materials, do you have to carry out additional testing, or fulfil additional certification criteria?

No new certification standards are involved but, since the reflectors were going to vary from unit to unit, we did a lot of additional testing. Essentially, we checked every combination of reflector, to make sure the performance was consistent. We always do test assembly and test installations, but with a novel product like this, we do a lot more, checking everything is OK in a wide variety of circumstances.

And because the housing is made from wood, you have to test more to ensure it’s entirely stable in terms of moisture and temperature variation. We knew we needed to achieve the standard IP20 protection rating, so there is no difference in what you reach, but it’s a more involved process to get there.

Can Kvisten be customised?

Because Kvisten has a wooden housing, it’s going to look like natural wood whatever you do. It does have a water-based lacquer coating that is 1% white. The lacquer is there to seal the unit and protect it from UV and the discolouration that can cause to unprotected wood, but other pigments can be substituted if required. In time, and for any customer that wants to work with us on a bespoke unit, we may investigate other finishes all together, but that’s not standard currently.

The LEDs offered as standard with Kvisten are rated for 50,000 hours of lifespan. But, if required, the luminaires can be used in conjunction with premium diodes for 100,000 hours. The rule of thumb we work to at Fagerhult is that we want to offer something that can last 20 years. How many hours that translates into depends on how many hours per day you have your lights on. With a location like a hospital or a warehouse, the answer might be 24/7. With an office, it might be 8 or 9 hours a day, with maybe nothing on weekends or holidays, so a lot less. For those customers, we find they don’t often request the premium diodes – 20 years is enough – and the 50,000-hour offering is primarily with those customers in mind.

To help bring Kvisten to the market within the same timescales as a standard fitting, we opted for a smaller initial standard assortment. This is because, when working with aluminium we already know the tolerance but, when working with completely new materials, we have to learn everything. In the next update we are including Tuneable White and CRI 90 within the standard assortment. They are available currently as customisations, but as the demand has been high we are making it easier for these options to be specified.

To make it comparable and transparent, Kvisten comes with an Environmental Product Declaration (EPD), providing clarity around Kvisten’s total environmental impact throughout its lifecycle.?For more information about Kvisten, and to download the EPD, click here. ?