Analysis of Exhaust Air Heat Recovery for HVAC Systems in Brazilian Cities

Javier Diaz Valdivia¹; Flávio Augusto Sanzovo Fiorelli¹

¹ Escola Politecnica da USP

doi:10.20906/CPS/COB-2015-0930

Resumo

Due to the internal air quality requirements, HVAC systems work with minimum levels of outside air rate that significantly impact the energy consumption of buildings. This has increased the use of efficient strategies that recover energy from exhaust air. Several studies demonstrate how heat recovery systems provide energy savings to buildings. However these savings are linked to several factors such as the operation of the HVAC system, the recovery system efficiency and climate conditions. Besides, these studies are limited to some climatic types that do not include tropical climates of Brazilian cities. Therefore this paper analyses the use of heat recovery systems in four Brazilian cities with different climate typologies, taking into account their effect on system performance and provided savings. Results indicate that the main energy reductions (2.5 to 5%) are connected to latent heat load reduction, particularly for humid climate cities.

Palavras-chave: HVAC Systems; Exhaust Air Heat Recovery; Brazilian Cities