Compact, High-Efficiency Air Handling Unit (CHE-AHU) for Residential HVAC Systems

AHUs for residential HVAC systems typically use low-efficiency blower fans (evaporator side) and simple axial fans (condenser side), and the fan and the surrounding High Resistance Mediums (heat exchanger. filter, burner, etc.) are treated as stand-alone components during design optimization. With the recent introduction of high speed electronically commuted motors (high- speed ECM), it is now possible to replace blowers with more efficient vane axial fans (i.e. rotor + stator fan blades). However, the fans and the surrounding High Resistance Mediums (HRMs) found in advanced AHUs are still designed and optimized as independent components. Recent studies on HVAC fan/HRM interactions at Syracuse University have discovered that holistic whole-system design optimization of the axial fan systems and surrounding HRMs can achieve highly compact, ultra-efficient, and low-noise fan/HRM systems. In particular, the presence of HRM’s (e.g. filters and heat exchangers) properly placed in close proximity to an axial fan system allows for higher blade loading (much higher than vane-axial fan designed as a stand- alone fan system), and with wider stall margin. The synergistic coupling between these components results in rotor/stator with fewer number of blades, rotor running at lower RPM for the same pressure ratio (hence noise reduction), along with a highly compact fan/HRM system. For this project, Upstate Parts & Supply, Inc. will collaborate with Syracuse University to develop a Compact, High-Efficiency Air Handling Unit (CHE-AHU) for residential HVAC systems in which the air management system (fan and surrounding HRMs) are optimized holistically. The fan technology we propose to use is the HRMs coupled with a vane-diffuser axial fan system, which is drastically different from current vane-axial fan design, and it is optimized in relation with HRMs placed just upstream and downstream of the proposed vane-diffuser axial fan. The end result is a closely coupled highly efficient and compact fan/HRM system. It is anticipated the proposed CHE-AHU will: 1) reduce energy consumption of the air handler by at least 35%, 2) improve the overall performance of the HVAC system by at least 7%, and 3) reduce overall size by at least 30% compared to current technologies.