Replacement of Conventional Fresh Air Handling Units with High Efficiency Units in High Rise Buildings – Benefits and Challenges

A completed project involved the replacement of conventional air handling units in active high-rise residential buildings with advanced control and energy-saving units on a one-to-one basis. This unique initiative distinguishes itself from traditional retrofitting endeavors by extensively incorporating advanced automatic control strategies. The primary goal was to minimize reliance on manual intervention, ultimately achieving electricity savings beyond the capabilities of standard retrofits.
In this project, 13 existing units in operational residential buildings were systematically replaced without significantly impacting the provision of fresh air. The newly installed units boasted enhanced design energy efficiency, resulting in an annual energy savings exceeding 30% in a hot climate zone.
The energy efficiency of the upgraded units was achieved through various features, such as high-efficiency Variable Refrigerant Flow (VRF) control. This ensured the precise quantity of refrigerant in alignment with load requirements. Additionally, energy-efficient fans for fresh air supply and stale air exhaust were incorporated, alongside the phasing out of environmentally-unfriendly refrigerants present in the existing units.
However, the undertaking was not without its challenges. Breaking open the building’s facade was necessary to facilitate the removal of the dismantled existing units and the installation of the new units, accomplished using cranes capable of reaching heights of 80 meters. Despite these challenges, all 13 new units were sequentially installed without causing any significant disruption to the ventilation required for the occupants.