Comportamiento termico de edificios de departamentos en Santiago de Chile: segmentación de nichos en el mercado inmobiliario privado a partir de las exigencias de la reglamentación térmica nacional

Abstract

Santiago de Chile (33°27’S and 70°42’W), capital city of the country, is placed in the central valley. It has a Mediterranean climate with a long dry season (between 7 and 8 months). Its annual average temperature is 12,2°C, whereas the thermal oscillation is considerable: there is almost 13°C between January and July average temperatures (hottest and coldest months, respectively) and the difference between maximum and minimum temperatures ranges between 10°C and 16°C during all the year. According to the National Statistics Institute, 37.4% and 36.0% of new housing during 2006 were built using mainly brick masonry and concrete in their walls, respectively. In both cases, thermal insulation was not generally considered. On the contrary for the heating period, a favorable thermal performance in summer should be expected (low thermal insulation in combination to high thermal mass). However, some recent studies show the completely opposite scenario, since an important percentage of users declare overheating in their own dwellings. This apparent contradiction could be understood from a database limitation, due to these official data do not reflect the impact of the current thermal regulation, which is in force since January 2007. Notwithstanding the required standards are weak in comparison to the international state-of-art (e.g. 1,9 W/m2K as maximum U-value for walls in Santiago), nowadays apartment buildings in Santiago are including at least 20 mm of thermal insulation in their walls to give compliance to the code. This paper proposes a series of dynamic thermal simulations to apartment buildings in Santiago, with the aim of establish the impact of different constructive solutions by means of thermal behavior, both in winter and summer. These digital models are statistically based on the typologies offered in the private real estate market during both periods 2001-2002 and 2006-2007, according to a database from Portalinmobiliario.com. These were determined using a multivariate analysis of their attributes – producing homogeneous market niches - through the hierarchical clustering technique. These homogeneous niches were identified in the real estate private submarkets, assessing different attributes. Thermal simulations were made using the TAS software, a dynamic-state digital tool. According to the results, the implementation of the thermal regulation – intended mainly to reduce heating consumption – have produced unfavorable comfort conditions in all the studied market niches, in comparison with the business as usual scenario. These conclusions allow establishing challenges and opportunities for the private real estate market, in order to integrate new thermal regulations with the private market reality.