Caracterización energética y condiciones de habitabilidad de las viviendas sociales del arquitecto Rafael De La Hoz en la ciudad de Córdoba. Escenarios de mejora
- Blázquez de Pineda, María Teresa
- Rafael Carlos Suárez Medina Director
Defence university: Universidad de Sevilla
Fecha de defensa: 21 October 2019
- Jesús Feijó Muñoz Chair
- Pedro Bustamante Rojas Secretary
- Olivia Guerra Santin Committee member
- Belinda López Mesa Committee member
- Ángel Luis León Rodríguez Committee member
Type: Thesis
Abstract
Current intentions to reduce the environmental global impact and a higher energy efficiency of the building sector have encouraged research on energy conservation measures and concrete actions suitable for sustainable development and the improvement of habitability conditions in buildings. In Spain, 61 % of the existing residential stock shows a deficient energy performance regarding prevailing energy standards, due to the fact that they were built before the first regulation on thermal conditions in buildings, the NBE-CT 79. Hence, improving this important amount of existing housing stock from the energy and environmental angle is a preferential issue to matter. This doctoral thesis pursues to set up a protocol for analysing the existing residential stock, by answering to three main aims, to increase the available data on the current state of these buildings as a previous step to intervene on them with any kind of upgrading action, to assess the level of thermal well-being inside the dwellings located under Mediterranean weather conditions by means of adaptive approach-based empirical models, to quantify their potential for improvement through the application of passive standard energy retrofit strategies that lessen the lack of thermal comfort, as well as shorten the annual energy demand and the associated CO2 emissions. In particular, the analysis protocol is applied to the existing social housing stock built between 1950-1980 in Córdoba, a city from the southern area of the Spanish Mediterranean arc, mainly focusing in the work of the Spanish architect Rafael de la Hoz, who entailed an architectural paradigm of Modern Movement by fostering the development of this sort of residential buildings. The environmental and energy assessment of the building stock is developed through a three-level bottomup approach: a detail level 1, at a territorial extent, centred in a promotion scale, which deals with the architectural and constructive characterization of the buildings, by their typological classification and the definition of the constructive solutions employed in their thermal envelope; a detail level 2, targeted to a building scale, which runs an energy characterization of the analysed buildings from the gathered information in the previous level, and quantifies their CO2 emissions and primary energy annual demand; a detail level 3, at a dwelling scale, in which a compilation of data about the current state of the buildings is gathered by means of in situ tests (infrared thermography and air-tightness of the outer parts of the buildings’ thermal envelope) and the monitoring of environmental and energy parameters, in three dwellings that belong to three social housing neighbourhoods made by Rafael de la Hoz, which turn to be representative of the investigated building stock after running a statistical analysis in previous levels. Thanks to the data collection under real use and occupancy conditions, the present research bridges the gaps between energy models simulation results and the energy performance of real case-study units. This allows to validate the potential of improvement of the studied buildings by way of passive standard energy retrofit strategies applied on the thermal envelope of the energy models that foresee an increase on thermal comfort in the dwellings, alongside with the decrease of primary energy demand and the CO2 emissions of this housing sector. To close the cycle, the scenarios for improvement assessed on the dwellings are transposed to urban and territorial scale detail levels (1 and 2), to quantify the obtainable benefits in global terms. In addition to the environmental and energy consumption and demand evaluation of monitored case-study dwellings, this doctoral thesis focus on the assessment of indoor conditions in them, and whether they really provide the users with a reasonable thermal comfort and well-being level. Usually, current energy standards and local regulations base thermal well-being requisites on a steady-state basis, and prescribe very narrow comfort temperature ranges, that imply a compulsory use of conditioning active systems (HVAC) to keep indoor temperatures between the threshold. On the contrary, the adaptive model offers a more realistic approach to thermal well-being, guaranteeing a lower need to use active equipment in maintaining indoor comfort, inasmuch the building runs in free-floating regime for longer hour, without needing the activation of HVAC systems. Given the empirical nature of the adaptive comfort equations, the applicability of two models that belong to experimental research and appear in international standards are examined, in order to set an adjusted model to Mediterranean weather conditions from Spanish B4 climate zone (Csa), as is the case of Córdoba. Particularly, ASHRAE Standard 55, with international scope of application, and Barbadilla-Martin et al. (2017) Standard MM, developed in the same climate zone as the analysed buildings, will be employed in the assessment and diagnosis of the lack of comfort in the considered housing stock by way of the adaptive approach. Hypothetical scenarios of intervention for the upgrading of this residential stock are targeted to the addition of thermal insulation in the opaque parts of the thermal envelope, implementing window glazing and joinery with improved thermal characteristics, together with more air-tight windows, and the incorporation of a mechanical ventilation system with a hygroregulable air-flow adjusted to occupancy needs. The individual analysis of each strategy leads to the formulation of an all-inclusive proposal that provides with a significant increase of thermal well-being inside the dwellings, bringing indoor temperatures closer to temperature ranges set by the adjusted adaptive comfort model (20.9 ºC in winter and 30 ºC in summer) achieving a 100 % of occupancy hours of thermal well-being. The all-inclusive strategy can be applied at urban and territorial levels of intervention concerning buildings that share similar constructive characteristics and obtaining a 30 % reduction of CO2 emissions and a 40 % decrease of primary energy annual demand in the building sector at a global scale. The aim to fill the gap of knowledge about the existing Mediterranean housing stock has led to the generation of a data base associated to a Geographic Information System, in which all the recorded data on the identification, definition and analysis of morphological, constructive and energy aspects of the residential stock has been organized and stored. The geographic data base is hereby presented as a tool for storing, analysing and data mining the current state of the residential stock, making it user-friendly and accessible to key stakeholders in charge of the development of energy retrofitting urban plans to upgrade these obsolete buildings.