Insulation - Warm welcome in the Isles

Where better to put a new insulation product to the test than the wind-lashed Orkney Islands? Energyflo, a lowcarbon, low-energy system of dynamic insulation devised by the Environmental Building Partnership, has been incorporated into a development of 32 homes on Orkney. This is nearing completion, and 20 more homes have already been commissioned. Heading even farther north to the Shetland Islands, the system has been installed in a bird observatory on Fair Isle.

Put simply, dynamic insulation aims to trap the warmth that escapes through the walls and roof of a building and return it inside. The idea is far from new, but the Environmental Building Partnership (EBP) claims to have perfected the process with the Energyflo cell, made from expanded and moulded polystyrene.

The cells are sandwiched inside the walls and/or roof of a building. The interior is slightly depressurised, using an extractor fan, flue or similar outlet, which causes the air outside to be drawn through the walls and into the building.

As the air passes through the insulation layer, it picks up the heat that was on its way out and returns it to the inside of the building, reducing the need for space heating. EBP says the product can be used in reverse for interior cooling and a trial of this is taking place in Abu Dhabi.

Early tests have shown savings of 13%-14% on the annual cost of space heating in homes insulated with Energyflo, according to Andrew Peacock, director of the company which is based in Alloa, Clackmannanshire.

He declines to reveal how much it costs, saying that Energyflo is still a prototype and negotiations for commercial production are ongoing.

“It will be at the higher end of the cost of conventional insulation,” he says.

Peacock claims that 144mm of Energyflo insulation will have the same effect as 350mm of mineral wool insulation, achieving a U-value of 0.05. He argues that this will allow builders to use thinner walls, giving them more interior space to sell and saving on materials.

“We may effectively reduce the capital cost of the building by more than the cost of the product,” he claims. EBP also claims that Energyflo can improve indoor air quality by trapping pollutant particles in the outside air and preventing them from entering the building.

UNIVERSITY ROOTS

Early tests have shown that homes insulated with Energyflo will see savings of 13-14% on the annual cost of space heating, the company claims

EBP is a spin-out from Aberdeen University, where Peacock worked on dynamic insulation with Mohammed Imbabi, the company’s chairman. It was established in 2004 and received a cash injection from Sigma Capital a year ago, which enabled a business development team to be recruited.

The two bosses haven’t altogether given up their day jobs: Imbabi is a parttime lecturer in engineering at Aberdeen University and Peacock is a part-time researcher into low-carbon buildings at Heriot-Watt University, Edinburgh.

Energyflo is to be installed in the roofing of 42 homes in Carlisle, constructed by Northern Developments, which will be built to level four of the Code for Sustainable Homes.

The product can also be used in commercial property and is being used by Nord Architecture in new roofing as part of a refurbishment of two five-storey office buildings in Glasgow.

EBP is working on 14 other retrofit projects, from Cumbernauld New Town in Scotland to a Victorian terrace in London, following its success in the Retrofit for the Future competition organised by the Technology Strategy Board, the government advisory body established in 2007.

Peacock says that when take-up increases, EBP plans to use an extra air cavity within walls, located just behind the plasterboard within a building, to provide the depressurising effect that draws air in from outside. This will mean that windows can be opened without affecting the performance of the product.

At present the system relies on the depressurising the whole interior of a building, which means that if a window is open, the fan will suck air in through it rather than through the insulation, although Peacock argues that this is only likely to occur on warm days. Small “feet” moulded onto the Energyflo cells can be used to ensure the cavity is built to the correct width.

Energyflo is undergoing assessment at the National Physical Laboratory and afterwards EBP will approach the Building Research Establishment to get the product’s details added as an option the SAP software used to calculate compliance with Building Regulations. This would give a further boost to sales.

“We are at a point where we can start running hard at the marketplace. It’s just starting to tip,” says Peacock. “Everyone knows that the zero-carbon targets for new buildings are coming. There’s a realisation that traditional methods will no longer satisfy requirements and there’s a hungerfor new technologies.”