Banca de DEFESA: ALEXANDRE GOMES DE OLIVEIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ALEXANDRE GOMES DE OLIVEIRA
DATE: 07/08/2024
TIME: 06:00
LOCAL: https://us02web.zoom.us/j/82858554102?pwd=NjVBR2l6THpqT3NxbGpWbncvR00xdz09
TITLE:

HIGHLY GLAZED OFFICE BUILDINGS IN WARM CLIMATES: THERMAL COMFORT AND ENERGY PERFORMANCE IN NON-UNIFORM THERMAL ENVIRONMENTS

KEY WORDS:

highly glazed facade, non-uniform thermal environment, office building, thermal performance, energy consumption, warm and humid climate

PAGES: 103
BIG AREA: Ciências Sociais Aplicadas
AREA: Arquitetura e Urbanismo
SUBÁREA: Tecnologia de Arquitetura e Urbanismo
SPECIALTY: Adequação Ambiental
SUMMARY:

This thesis addresses the inadequacy of highly glazed facade office buildings in warm climates, which has been debatable for decades due to its impact on the internal environment comfort and energy consumption caused by the non-uniform thermal environment. Despite the glass technology developments, buildings with ordinary laminated glass and unknown thermal properties became commonly accepted in Brazil's most populated cities in the low latitudes, opposing primary bioclimatic and energy efficiency design recommendations. The main objective is to identify the impacts of highly glazed facades of office buildings in low-latitude warm climates. The first approach was a short-term thermal assessment of five case studies in Fortaleza (3.7327◦ S, 38.5270◦ W), the fifth-biggest Brazilian city. Combining the walk-through audit with thermal monitoring at the centre of office rooms and next to the facade resulted in comparing air and operative temperatures, and the PMV index, under different environment configurations. Surface temperature measurements with thermographic photos complemented the thermal analyses. The case studies confirmed different simultaneous thermal sensations between perimeter and centre zones. The perimeter zones barely reach PMV 0.5, achieved by the users' adaptations that mitigated the thermal radiation from the facades, obstructing the windows with internal shades or avoiding the window view by changing the layout. Therefore, the extensive use of window obstructions compromises other indoor environmental aspects, such as daylighting and exterior view, contradicting the architects' expectations of a transparent glass building. The second approach assessed three main effects through building simulation on EnergyPlus: the non-uniform thermal environment on thermal zoning, thermal environment control on thermal comfort and energy consumption, and facade design alternatives on energy consumption when thermally comfortable. Results determined the most suitable thermal zoning caused by the effects of longwave radiation from the glazing surface, resulting in three subzones: a perimeter zone, 2.5m deep, highly impacted by the façade; an intermediate zone, 2.5 to 5.0m apart from the facade, moderately influenced; a core subzone, 5.0m apart from the facade, slightly affected by the facade design. An air temperature-based thermostat barely provides thermal comfort for the three subzones at the expense of higher cooling energy consumption. The perimeter subzone requires air temperature below 20°C to ensure thermal comfort, and the intermediate and core subzones require only 23°C and 24°C, respectively, to compensate for the non-uniform thermal radiation.  The conventional 23°C  cooling setpoint recommendation cannot provide acceptable thermal comfort; decreasing the setpoint to 21°C increases cooling energy consumption by approximately 10%. On average, diminishing the setpoint temperature with an increment of 1°C increases 5.3% of cooling energy consumption. Operative temperature control has been confirmed to be more efficient than air temperature control, and the 26°C cooling setpoint ensures thermal comfort and saves approximately 10% of cooling energy consumption. Facade design with lower SHGC had a relevant impact on increasing thermal performance and comfort and reducing cooling energy use, but most prosaic alternatives, such as lowering WWR or adding external shading, resulted in equivalent or even better performances. Based on both approaches, different thermal zones occur in a single zone, causing the need to reduce the cooling setpoint to avoid the warm discomfort in the perimeter area, which tends to generate thermal discomfort to cold in other places, increase cooling energy consumption, and permanent windows obstructions with loss of external view and daylight due to the occupants' adaptation to compensate the glazed facade poor thermal performance.

COMMITTEE MEMBERS:
Presidente - 1454154 - ALDOMAR PEDRINI
Interna - 1694892 - EDNA MOURA PINTO
Externo à Instituição - RICARDO FORGIARINI RUPP
Externa à Instituição - CHRISTHINA MARIA CÂNDIDO - SSADP
Externa à Instituição - SOLANGE MARIA LEDER - UFPB