Home energy ratings seem reliable, but are they? We look at the results from one experiment that tries to answer this question for the existing homes market.
A comprehensive technical and social refurbishment of a housing estate built in the seventies is carried out in the Gardsten project. Well thought out traditional measures are combined with newenergy technology which was initiated through participation in an EU project which, in turn, is based on IEA collaboration.
The governing parameters for flows generated by heat transfer from solar cell modules to air gaps are discussed. Experimental results are presented from measurements in mock-ups of ventilated facades and roofs. The heat transmitted from the solar cells to the air have been mimicked by the use of heating foils. The inclination angle of the roof, position of solar cell module and the height to width ratio (aspect ratio) have been varied. The bulk properties as the air flow rate in the air gap, local temperatures and velocities have been measured.
As the ratings industry in the United States shifts from a subsidized market to an unsubsidized one, we look at four areas of opportunity for home energy raters. Will these opportunities be growing or collapsing in the 21st century?