Winter energy behaviour in multi-family block buildings in a temperate-cold climate in Argentina

Abstract

This paper analyzes the thermal and energy behaviour of apartments in three-story block buildings located along a NE-SW axis (azimuth = 120°) in a temperate-cold climate (latitude: 36°57′; longitude: 64°27′) in the city of Santa Rosa, La Pampa, central Argentina. Four apartments had been monitored during May and June 2009. Three of them are located in Block 126. Two of these apartments face South: 15 and 23 on the SE end, ground and first floor, respectively; 18 faces N on the second floor. Finally apartment, 12 is located in Block 374, on the first floor, faces N and shows a carpentry-closed balcony. The purpose of this work is – to study the evolution of the indoor temperature in each apartment; to analyze energy consumption and comfort conditions; to study energy potential and energy intervention in order to reduce energy consumption; to analyze bioclimatic alternatives feasibility and the possibility to extrapolate results to all blocks. On the basis of the analysis of natural gas historical consumption records, results showed that regarding heating energy consumption during the period May–June, Apartment 12, facing N, with its only bedroom facing NW and its carpentry-closed, transparent glass balcony, presented a mean temperature of 21.2 °C, using a halogen heater for 6 h/day between 9 pm and 2 am (0.16 kWh/day/m²). Apartment 15, on the SE end, first floor of the block consumed 22.5 kWh/day (0.43 kWh/day/m²) (mean temperature = 22.2 °C). Apartment 23, located on the second and top floor (on top of Apartment 15) with higher energy loss, consumed 28 kWh/day (0.54 kWh/day/m²) (mean temperature = 23.7 °C). Apartment 18, also on the second floor and facing N, located in the centre and with its only bedroom facing SE, consumed 18.8 kWh/day (0.48 kWh/day/m²) (mean temperature = 22.3 °C). Apartment 23, with higher thermal loss through its envelope, but with heat transfer from the apartment located below, is the one that showed the highest level of consumption/m². Closing the balcony with carpentry produced an important reduction of energy consumption while reaching comfort conditions. The analysis of the experimental results allowed: (a) to determine through analysis of historical consumption of natural gas prior to the year 2009 that the owner lived under conditions of comfort, (b) to evaluate possible interventions in the building that would lead to saving heating energy. Thermal insulation of roof and envelope appears as the most feasible alternative whereas closing balconies constitute a very good design option in winter.