SBIR-STTR Award

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.

The proposed research and development project addresses the need to improve the energy efficiency of heating, ventilation, and air conditioning (HVAC) systems in residential buildings throughout the US. The project uses an innovative holistic approach to redesign key components of the air handling unit (AHU) in forced-air HVAC systems that are installed in at least 84 million residences, including in 80% of 73.9 million single-family detached homes. The goal of the project is to develop and demonstrate a next-generation “Compact, High-Efficiency Air Handling Unit (CHE-AHU)” that reduces the size of the AHU and achieves DOE’s goals for reducing the energy required to circulate conditioned air by at least 25% without increasing the cost of unit. The “air side” of conventional residential AHUs includes three key components: 1) a filter, 2) one or more heat exchangers, and 3) an air mover (e.g., a blower or a fan that is driven by an electric motor). Traditionally, the heat exchangers and the air mover are designed as standalone components. The proposed project advances prior research results that identified the possibility of designing the combination of the filter, the air mover, and the heat exchanger(s) holistically as an integrated system that achieves higher efficiencies than are possible with conventional design approaches. In the Phase I STTR project, the team used advanced computational fluid dynamics (CFD) software to evaluate the performance of a state-of-the-art commercially available AHU and to develop designs for two possible configurations for the envisioned CHE-AHU. The results of the CFD simulations predict that both configurations of the CHE-AHU promise to exceed DOE’s goal for reducing the energy required to circulate conditioned air through the unit AHU throughout the household by at least 25%. In the proposed Phase II STTR project, the team will advance research and development on the two CHE-AHU configurations, including building and testing prototypes and refining the design of the integrated filter-air mover-heat exchanger subsystem. The goal of the proposed Phase II project is to develop a proof-of-concept CHE-AHU prototype that can be demonstrated to a major Original Equipment Manufacturer (OEM) that is already well-established in the US market for residential HVAC products. The innovative concept in the CHE-AHU is applicable to a wide range of HVAC systems in addition to AHUs used in residences. The innovation is expected to be attractive for use in a variety of HVAC applications in commercial and industrial buildings, including especially in hospitals and clean rooms, which require very compact, high-performance air handlers that may include capabilities for disinfecting the air.