This webinar, led by Dave Milligan from Innovent, focuses on the design, features, and applications of air source heat pumps (ASHPs) and their role in the push toward electrification in HVAC systems. The presentation covers the technical aspects of ASHPs, their performance in different climates, and complementary technologies like energy recovery that enhance their efficiency.
Dave begins by introducing Innovent, a custom manufacturer based in Minnesota that specializes in designing HVAC equipment tailored to specific customer needs. The air source heat pump is a relatively new addition to their product line, with capacities ranging from 6 to 126 tons. The system utilizes Copeland variable frequency drive (VFD) compressors and is designed to use the R454B refrigerant, which will become the industry standard starting January 2025. The ASHP includes advanced features such as Ziehl-Abegg condenser fans and custom controls, making it more complex than typical air handlers.
One of the key points in the presentation is the performance of ASHPs in cold climates. While ASHPs can operate efficiently in various conditions, their performance declines when ambient temperatures drop below zero degrees Fahrenheit. At such low temperatures, supplementary heat, such as electric heat or hot water systems, is required to maintain proper heating. Additionally, to prevent the outdoor coil from freezing during heating mode, ASHPs need to periodically switch to a defrost cycle, which temporarily reduces heating capacity. This makes it important to have backup heat sources, especially in colder regions like Colorado.
Dave emphasizes the importance of energy recovery, particularly in systems using 100% outdoor air or those operating in climates with extreme temperatures. By integrating energy recovery systems, which capture and reuse heat from exhaust air, overall efficiency is significantly improved, and the need for additional heating can be reduced. Innovent offers energy recovery as a standard feature in many of their products, including their air source heat pumps.
The presentation concludes with a discussion of ideal applications for ASHPs, such as comfort cooling, heating, and dedicated outdoor air systems (DOAS). However, ASHPs may not be suitable for applications requiring precise temperature control or high supply air temperatures, such as certain industrial processes. Dave also introduces the ACU Block, an advanced energy recovery device with sensible efficiency rates of up to 95%. This device, which originated in Europe, provides highly efficient energy recovery and reduces the need for frost control in colder climates.
In summary, air source heat pumps are a versatile and energy-efficient solution for many HVAC applications, particularly in regions with moderate climates. When combined with energy recovery systems, they offer significant energy savings and can help meet growing electrification and carbon reduction goals. However, in colder climates or highly specific industrial processes, careful design considerations and supplementary heating systems are necessary to ensure optimal performance.