Spiralite has created a ductwork product for use in heating, ventilation and air-conditioning that it says is cheaper, lighter and up to 40% more energy efficient than traditional steel versions. The Essex firm’s patented technology has been installed in buildings including Guy’s and St Thomas’ Hospital in London. It is also developing antimicrobial linings for ducts. It secured £4.8m in funding from the venture capital firm Octopus Investments. Sales reached £9.4m in 2015 under managing director Mel Ragnauth, 41.