Test cell data-based predictive modelling to determine HVAC energy consumption for three façade solutions in Madrid

This study aims to narrow the gap between predicted and actual energy performance in buildings. Predictive models were
established that relate the electric consumption by HVAC systems to maintain certain indoor environmental conditions in
variable weather to the type of façade. The models were developed using data gathered from test cells with adiabatic envelopes
on all but the façade to be tested. Three façade types were studied. The first, the standard solution, consisted in a double wythe
brick wall with an intermediate air space, the configuration most commonly deployed in multi-family dwellings built in Spain
between 1940 and 1980 (prior to the enactment of the first building codes that limited overall energy demand in buildings).
The other two were retrofits frequently found in such buildings: ventilated façades and ETICS (external thermal insulation
composite systems). Two predictive models were designed for each type of façade, one for summer and the other for winter.
The linear regression equations and the main statistical parameters are reported.