22 million US dollars for tight air ducts
Buildings account for around 40 % of total energy consumption in the USA and Europe. Heating and cooling consume a good 50 %, and another "energy destroyer" is air conditioning and ventilation systems, which lose up to 30 % of the transported air through leaks, holes and poor connections. In order to avoid these unnecessary losses and to be able to realise the climate-neutral building stock by 2050 agreed in the Paris Climate Agreement, Breakthrough Energy Ventures, a climate fund supported by Bill Gates, is investing 22 million US dollars in Aeroseal LCC.
The investment of 22 million US dollars from the Gates-supported Climate Fund for Aeroseal LCC, based in Ohio, USA, makes it clear that improved energy efficiency of buildings is one of the most effective ways to reduce greenhouse gas emissions and counteract global warming. Many years ago, Aeroseal LCC specialised in improving the energy efficiency of homes and offices and realises this by sealing air duct systems. "Small amounts of leakage are a big deal," says founder, Mark Modera, who found in experiments at Lawrence Berkeley Laboratory that turning on the air conditioner tripled the air exchange rate in a home, brought energy efficiency to its knees and increased costs. The reason: leaky duct systems.
Small particles with a big effect
In order to seal these simply and cheaply, Aeroseal LCC has developed a process in which leaks in air duct systems can be reliably eliminated without having to locate them first. Instead, a sealant is atomised into tiny particles and sent through the leaking duct system together with the air. As the pressure drops locally at leaks, holes, gaps and cracks are flowed through from the inside to the outside. In the process, tiny particles of sealant are deposited at the edge of the leaks and permanently seal them up to a diameter of 15 mm. Sealing air duct systems in a newly built house usually takes less than an hour. The cost is around $500 to $600. In an occupied single-family home, expect up to six hours and $1,500 to $2,200. And even in commercial buildings, the downtime and costs are so minimal that payback periods - depending on building type, type of use, air volumes conveyed, etc. - are typically 0.5 to five years.
Role model USA with positive effect for Europe
"We see our technology as an important building block for net-zero houses," says Aeroseal Chief Executive Officer, Amit Gupta, laying a foundation stone for a climate-neutral building stock. Already six years ago, MEZ-TECHNIK GmbH, Reutlingen, recognised the signs of the times and brought the Aeroseal process to Germany. Since then, 33 independent partners have been acquired in 16 European countries, who now benefit from the financial as well as idealistic support from America and make their contribution to a cleaner planet. The fact that the sealing of air duct systems is an important point here is shown not least by the fact that the Aeroseal process has been eligible for several subsidies in Germany for some time. Builders and owners benefit from tight air ducts because they contribute to lower electricity bills and better indoor air quality. "Instead of smelling what the neighbours are cooking or getting high through and with the neighbours in California, where marijuana is now legal, leaks between flats can be sealed easily and reliably," says Modera.