LAUSR

Abstract The numerical thermal performance of walls made out with materials available on the Mexican market: red brick (L), solid block (T) and hollow block (B) is presented. Each wall with a passive cooling technique was studied for a period of 24 h (warmest and coldest days) for three cities of Mexico with predominantly warm weather (Merida, Zacatepec and Hermosillo). In order to carry out the thermal analysis of each wall, four configurations were defined as follows: L, T and B stand for red brick, solid block or hollow block as the construction material respectively, and the numbers 1, 2, 3 and 4 stand for an added single layer of plaster (reference case) (1), an added layer of plaster plus a layer of white reflective coating (2), an added layer of insulating material plus a layer of plaster (3), an added layer of insulating material, plus a layer of plaster plus a layer of white reflective coating (4), giving as a result alternate configurations defined as (L1), (L2), (L3), (L4), (B1), … , (T4). In general, results showed that configurations L1, T1 and B1 increased considerably the total thermal load in all the three cities, compared to configurations L4, T4 and B4, respectively. For the city of Merida, Zacatepec and Hermosillo, configuration T4 resulted with the lowest thermal loads: 983.75, 1095.5 and 1540.72 W-h/m2, while configuration T1 had the highest thermal loads: 1831.22, 1859.86 and 2686.91 W-h/m2, which represents an increase of 48.8, 41.1 and 42.7% regarding to configuration T4, respectively. Finally, the configuration with the lowest thermal loads and economically viable based on the recovery of investment time was configuration T4, with a recovery time lower than 60 months and a reduction on the thermal loads between 41.1 and 48.8%. On the other hand, the recovery time for configuration B4 went beyond 115 months and the reduction on the thermal loads varied between 34 and 42%.