Sistema de climatização ambiental automatizado em modo misto para uso em edificações residenciais na zona bioclimática brasileira 2

Abstract

The strategy of Hybrid Ventilation (VH) or mixed mode (MM), switching between the use of natural ventilation (VN) and air conditioning (AC), is a way to reduce expenses with artificial conditioning systems and achieve thermal comfort residential use, in addition to the gains in internal air quality, since in VH the use of the artificial air conditioning system is partial, occurring only at times of day when the internal conditions are outside the established performance standards and integrated with the passive conditioning strategies (VN). The objective of this work is to evaluate the VH strategy regarding the thermal comfort and potential of energy saving in a residential building in the Brazilian Bioclimatic Zone 2 (ZB 2). The influence of hybrid ventilation on thermal comfort and energy consumption was investigated by means of a temoenergetic simulation of a single family residence, Casa Popular Eficiente, implemented in the city of Santa Maria / RS, using EnergyPlus software. Two reference simulations were defined, one with artificial air conditioning and the other only with temperature - controlled natural ventilation and 2 base cases with 3 climatization scenarios each, these scenarios were simulated with variations in the types of controls for hybrid ventilation (VH), the which also incorporate the control of solar radiation through the automation of blinds. Finally, openings for natural ventilation were controlled through the Energy Management System (EMS) advanced feature of the EnergyPlus software. The results obtained demonstrate that the strategy of hybrid ventilation in its best configuration reduced the consumption with air conditioning in 51.40% for the control based on the ASHRAE 55 standard and 16.05% in the temperature control optimized by means of algorithm via EMS, in relation to the configuration using only artificial air conditioning. The use of solar shading (blinds) was efficient in reducing 1.38% in the annual consumption of electric energy, when using the strategy in mixed mode of air conditioning, obtaining better performance for the control based on ASHRAE 55. With regard to thermal comfort, in the summer, the worst situation occurs when the building uses only natural ventilation (VN) controlled by temperature, reducing thermal discomfort by adopting hybrid ventilation, maintaining the internal temperature for longer in the range of desirable temperatures for the thermal comfort sensation and representing a reduction of 2337.71 GHR for the optimized temperature control through the control algorithm and 1645.62 GHR for the control based on. ASHRAE, compared to the reference configuration, with only natural ventilation. The use of sunscreens was also efficient in reducing the parameter Degrees-Hour Independent of the control adopted when opting for the mixed mode of air conditioning or hybrid ventilation, the building reduced the energy consumption, improving thermal comfort. Therefore, this research demonstrated that through the management, control and integration capabilities possible through automation, it is feasible to optimize the ambient air conditioning through the implementation of the hybrid ventilation in conjunction with the shading to control the thermal gains through the radiation and, in this way , improve levels of thermal comfort and reduce energy consumption.