Experimental analysis of a prototype for a thermochromic Trombe wall

Ambitious and innovative refurbishment measures will be required to meet the European Union's goals for limiting building energy consumption. Envelope efficiency can be enhanced, for instance, with new materials and improved passive techniques. Trombe walls (TWs), one such technique, reduce heating demand in winter, although they cause overheating in warm climates. That drawback may be corrected with thermal-optically reversible materials. In this study, a thermochromic mortar was applied to a prototype TW to reduce solar absorption in summer without affecting its wintertime efficacy. Further to field measurements, the maximum surface temperature reached on the wall's thermochromic cladding (TCC) was 32°C in winter and 44.7°C in summer. The indoor cold weather temperature in the module ranged from 7.9°C to 16.5°C for a mean of 11°C, compared to 25.1°C to 32.2°C with a mean of 28.9°C in warm weather. Ventilating the air gap at 60-200 ach prevented the cladding from fading to nearly colourless in winter. In light of the improved thermal transfer performance delivered, the TTW proposed can profitably be used for energy refurbishment in existing buildings.