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Best practice applied reseach from Finland: 'Accurate tool for targeted energy renovations: the U-value meter'

posted 25 Oct 2013, 07:00 by UASnet   [ updated 25 Oct 2013, 07:02 ]

Be aware of massive uncertainties in the value of your lifetime investment – your home!

The EU is progressing towards sustainable energy systems, outlined fundamentally in directives 2010/31 and 2012/27. The primary goals are that by 2020 all new buildings will be very high energy performance, nearly “zero-energy”, buildings and CO2 emissions will be reduced overall by 90% in 2050.

What remains as the most challenging issue to be solved? Naturally, bringing the millions of energy-wasteful older buildings throughout Europe up to modern requirements in energy efficiency. Their energy characteristics should also match the overall goals. Consequently, extensive and massive renovations are required. Allocation and sequencing of the coming renovations action is the most extensive risk for any residence owner. Partial renovations should be performed according to profitability. This is directly defined by the impact on energy efficiency and required cost of the respective renovation action.  

Energy consumption in residences is the sum of household electricity, hot water and heating. The first two are both easily measured and allow identification of the most significant energy loads and thus targets for extensive savings. Heating and its respective energy losses are, however, much more challenging to quantify. Heat is dissipated through the building envelope, but the energy loss is distributed unevenly. It would be most beneficial if true values of heat flux could be analysed in detail to reveal the extent of energy loss in different positions.

We have developed at Arcada a unique instrument for the analysis of heat flux through building envelopes. It analyses insulation characteristics and gives directly true heat flux “U-values” (W/m2·°C). The instrument is lightweight and using tape mounts easily onto any surface. The required time for a single measurement is typically only 30 minutes. We foresee that experts performing heat loss inspections would have 10 such devices, and so could complete a detailed analysis of an average-sized house in around 3 hours and with more than 40 single measurement values- detailed information indeed. The house owner benefits from the analysis as the results would form the foundation for renovation plans. The final outcome equates to a cost optimal renovation with an expected outcome in terms of energy efficiency.