Wednesday, June 22, 2005

LED's: A Bright Idea?

Is it a home? Is it a showhouse? Is it a spaceship? Visitors to the Vos Pad can be forgiven for their confusion because this unique apartment, overlooking the Thames near Chelsea Harbour, is perhaps a bit of all three.

The Vos Pad is a home to Marcel Jean Vos, a Dutch designer and property developer. Marcel has been renovating apparently modern two-bedroom flats in London for several years, stripping out the cheap and inadequate interiors placed in by the original builders and customising them for a wealthier, largely single clientele. There are certain tricks of the trade which he has learned over the years: getting rid of the second bedroom, enlarging the bathroom, installing underfloor heating under limestone flooring and adding some good lighting. Especially the good lighting. Marcel became more and more interested in lighting design and began to feel that many of the current fashions, especially the near universal use of halogen downlighters, were actually rather bad lighting, being harsh and unforgiving. He looked at the emerging technology of using LEDs (light emitting diodes) and started to incorporate them in a limited way in one or two of his conversions.

Then he appears to have been hit by a brainwave. Why not use nothing but LEDs in his next apartment? No one else has ever done this before. Not in the UK. Not in Europe. In fact, nowhere at all. It was both a challenge and an opportunity. The Vos Pad was born.

LEDs have existed since the 1960s — in red. We have grown used to them being used in displays for calculators and digital clocks but we tend to think of them as being useful only for intricate task lighting and displays. However it took nearly 30 years for them to make a blue LED and even longer to produce a white one. Whilst red and green LEDs are produced in millions and are incredibly energy efficient, the blue and white colours were expensive to produce and used a lot of power. But improvements in the manufacturing process are being made all the time and the American lighting firm Luxeon have recently produced an LED that has the optical power to take on conventional lighting. Luxeon's LEDs have a precise beam with minimum glare, operate on a tiny current, generate almost no heat and have an anticipated bulb life of 50,000 hours, way above anything sold commercially as a lightbulb — a compact fluorescent, long life bulb is reckoned to last about 8,000 hours in comparison.

The Vos Pad is lit by no less than 105 light fittings, each containing three LEDs, one red, one green and one blue. Turn them all one together and they produce a very clear white light though dimming controls mean that the colour mix can be varied to produce either a warmer colour or fully fledged coloured party lights. What is perhaps more remarkable is that all these 105 lights are mounted in the floor, pointing straight up at the ceiling. "This is actually a very good way to light a room," said Marcel. "Washing the ceiling with light — uplighting — is a much gentler way of providing light to a room and it gives a far more even light quality." It's only possible to do this because the LEDs produce almost no heat so there is no risk of fire or burning at floor level. Additionally, the LEDs operate at such low current that they have been wired together using low voltage data cabling, Cat 5, better known for networking computers and telephones.

To get the floor lighting effect correct, the Vos Pad has been carefully designed in the minimalist style. The surfaces are all white or off-white and there is a minimum of soft furnishings around. The walls have been kept pretty bare and the lights have been arranged around the perimeter of the room. Even so, the uplighting wash is effective enough to ensure that the overall effect is a very even light throughout. To showcase their capabilities, Marcel has also chosen to fit LEDs into the spa bath (the fittings are waterproof) and within the kitchen's glass worktop.

At the moment, LEDs are still someway short of becoming mainstream. There are still few suppliers and very few electricians will have ever come across them. Prices for fittings are still on the high side, especially considering how many fittings you need to light a flat. TLC, a discount mail order supplier, is selling white LEDs for £25 each. But on the plus side, the power consumption is negligible — with every light on in the Vos Pad, the power consumption is only 300watts, about the same as five ordinary bulbs. And the longevity of the lamps means that it is unlikely they will ever have to be replaced. If the trend towards lower prices for Leds continues, it will only be a matter of time before other homes appear using this amazing technology for lighting.

In the meantime, Marcel Vos hopes to become more than just a groundbreaker. His first step in creating an LED-lit apartment has aroused enormous interest from fashion magazines and property developers and he has started a consultancy, Vos Solutions, to kick start the LED lighting revolution. Given time, LEDs may become as commonplace as low voltage halogen downlighters: but this won’t happen without a great deal of encouragement and vision from entrepreneurs like Vos.

Vos Solutions 0207 384 0714

Mark Brinkley

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Tuesday, June 21, 2005

Part P will add to Cost of Building

New building regulations, which according to the Government are aimed at curbing the unacceptable number of deaths, injuries and house fires caused by faulty electrical installations, came into force on January 1.

The unacceptable number of deaths figure seems to hover around the 10 mark annually and that it is by no means clear how the implementation of the new regulations, known as Part P, will reduce this figure, although it will add significantly to costs for builders. Rather like the CDM regs which were introduced in 1994 to a fanfare of publicity about how many lives would be saved: since their implementation, construction site deaths have increased.

Part P inspections do not apply to small electrical works in the home, which are arguably the most dangerous because they are more likely to be undertaken by complete novices. There is also no requirement for a first-fix inspection which would uncover dubious practices like running cables diagonally across walls, the kind of mistake which electrocuted MP Jenny Tongue's daughter last year. Some qualified electricians may undertake first-fix inspections but a large number will only be notified after the works have been completed.

Another interesting aspect of Part P is that it applies exclusively to dwellings: it's the only building regulation to do this. This may be in an attempt to reduce the number of fire brigade call outs for domestic fires, which average around 7,000 a year and cost nearly £50 million a year. But the feeling is that the implementation of Part P will have negligible impact on safety, deaths by electrocution or fire service costs but will add between £150 and £300 to the cost of building a new house or an extension.

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Mark Brinkley

If you can only see this single article on screen please click on the 'Housebuilder's Update' heading (screen top left) to view the rest of this month's items and have access to our archives.

Sunday, June 19, 2005

Temparature Rises in Insulation Debate

Testing the effectiveness of insulation is notoriously difficult. Mark Brinkley reports on the merits of laboratory vs field testing.

The world of thermal insulation is well used to professional rivalries and knocking copy, but a current spat between rival manufacturers threatens not merely competing products but the whole system of third party accreditation which underpins construction innovation in Britain.

At the heart of the dispute is the claim by the French firm Actis that it's top selling product, Tri Iso Super 9, a reflective multifoil only 25mm thick, is equivalent to 200mm of mineral wool. This claim, substantiated by BM Trada and thereby widely accepted by building control and the NHBC, is hotly disputed by manufacturers of competing products and now one of them, Celotex, has commissioned independent tests which it hopes will disprove it.

Behind the dispute lies a battle for the future of roof insulation. As the thermal regulations become ever tighter, designers and builders have been struggling to accommodate the necessary insulation within the roof fabric. Mineral wool is now rarely used because it's simply not efficient enough to give a sufficient U value within the rafter void. Foam board manufacturers, principally Kingspan and Celotex, have been benefiting hugely from the legislative changes but have also found that they have been loosing market share to reflective multifoil insulation.

Richard Crisp, marketing director for Celotex UK, said: "We became acutely aware that sales of Actis and other multifoils were growing. If it works as advertised, then we would like to be making it or, at least, selling it. So we set out to see if it was as good as it claimed to be." Celotex paid for samples of the Actis to be independently tested by the National Physical Laboratory in Teddington. There, it was subjected to the standard test for thermal insulation, known as the guarded hot box test. To be equivalent to 200mm of mineral wool, the R value measurement would have to have been around 5.0: in fact, Actis scored just 1.7. Used in a roof application, this would give a U value of between 0.5 and 0.6, whereas the latest Part L requirement is much lower, at just 0.2.

The NPL labs results were in line with test data from Germany, Canada and the USA for reflective multifoils. So how has Actis managed to achieve acceptance in the UK market and why have BM Trada seen fit to give it their stamp of approval? The answer lies in what is being tested and the relative importance of conduction, radiation and convection.

Actis claims that the guarded hot box test looks principally at rates of thermal conduction whereas their product works by stopping other channels of heat loss, principally radiation, convection and unplanned ventilation. They prove their product by building comparison roofs and measuring the heat loss from each. If a roof insulated with Tri Iso Super 9 can be shown to perform to the same standard as one built with 200mm of mineral wool, then the thermal characteristics must be equivalent. Actis last undertook such test in 1997. It was verified by BM Trada who checked the design, construction and the test data and subsequently gave it their stamp of approval.

On the back off this one test, multifoils have been given the green light to sell into the UK market as being equivalent to 200mm of mineral wool. Other multifoil manufacturers have only to prove themselves to be as good as Tri Iso Super 9 for them to be accepted. One such, YBS Super Quilt, has even used the National Physical Laboratory to show "a 13.7% better performance than its nearest competitor" without publishing what the actual test results are.

During the next 12 months, Part L is due to be tightened again. The multifoils are faced with another hurdle, for it will no longer be enough to be equivalent to 200mm of mineral wool. Rather, it is believed that the new standard will be around 250mm of mineral wool. Actis already have a new product in production, known as MultiPro TS 250, and testing is underway to show its performance characteristics. It's essentially the same product but with eight reflective layers instead of six. Industry watchers are awaiting the test results with interest, but few are anticipating anything different to the previous tests. (site in French)

Housebuilder's Update background:

Insulation: the murky science

Ever since thermal conductivity rates were first measured and compared, there has been debate about just how relevant they are. It is accepted that heat moves through the building fabric via four different methods, conduction, convection, radiation and ventilation, and also that the more complex the structure, the more difficult it is to model what is happening within it. There is also likely to be a huge discrepancy between laboratory results and as-built performance, similar to what has been found with sound insulation designs. The regulatory authorities accept laboratory measurements as gospel: there is remarkably little post-completion testing carried out, if only because a whole building is such a complex system that it's impossible to isolate the effect of one particular component.

The field is therefore open to anyone who can show that their product performs as well as, or better than, a competitor.

Reflective multifoils are being sold as the answer to every roof builder's problem: how to build in really good insulation levels without having to deepen the roof profile. They hardly rank as an innovation, having been around for decades, but until recently they were always seen as being too expensive compared to the wools and foams which builders more normally work with. But with Part L demanding ever increasing depths of insulation, multifoils have come into their own and are they are now taking an increasing market share.