ASHRAE and The AHR Expo Have Announced The 2021 AHR Expo Innovation Awards Winners

Ashrae and the AHR Expo have announced the  2021 AHR Expo Innovation Awards winners, with  Advanced Cooling Technologies, Inc. (ACT) winning the competitive Green Building category with its Pump-Assisted Split Loop Energy Recovery Heat Exchanger. The award announcement noted that this product received high marks on its value and application, along with the flexibility of geometric design being a key reason for its success.

ACT’s Pump-Assisted Split Loop Energy Recovery Heat Exchanger offers the highest levels of energy recovery and cost savings year-round for split airstreams. This product provides unprecedented installation flexibility, enabling installation for applications having a wide variety of duct layouts (e.g., over, under, side by side, and far apart over long distances). Estimations show annual operational savings in the hundreds of thousands of dollars for buildings requiring a large amount of outside air to maintain the highest indoor air quality, which is especially attractive in today’s Covid awareness climate.

AHR is a yearly tradeshow for the Air Conditioning, Heating and Refrigeration industry, and each year they accept submissions for new products that are moving the industry forward through innovation. While the AHR in-person Expo has been cancelled for 2021, the innovative product competition was still held and was judged by ASHRAE experts, each with over 20 years of industry experience.

Product information provided to the ASHRAE panel:

What is Pump-Assisted Split Loop Energy Recovery HX?

ACT’s Pump Assisted AAHX recovers energy all year long, from either the exhaust or supply air stream (depending on the season), allowing AHUs to be sized smaller and to consume less energy. Combining traditional air-to-air heat pipe technology and pumped two-phase systems takes advantage of both operational modes. In passive mode, the heat exchanger operates as a heat pipe with no electrical input required. This mode activates when the warmer air stream is physically below the cooler air stream. When the seasons change and the relative temperature of the two air streams is reversed, a small pump is utilized to maintain the transfer of energy. Since the method of heat transfer inside of the heat exchanger utilizes the latent heat of the working fluid, the amount of flow rate required to transfer large amounts of energy is a fraction of an equivalent glycol loop. It’s the combination of passive operation for at least half of the year and very minimal energy consumption during active operation for the other half of the year that enables such high overall energy recovery from this product.

What makes this revolutionary?

  • Energy Efficiency: The two-phase nature of this product makes it far more effective and energy efficient than an equivalent glycol run-around loop, providing 50% faster payback periods than an equivalent glycol system.
  • Temperature control: Optional active control valves and pump controls mean that the heat exchanger can provide relatively precise temperature control and defrost capability without the need for inefficient bypass dampers that require a significant increase in the air handler size.
  • Compact Packaging: The coils and pumping components can be packaged very tightly, allowing these systems to fit nicely into standard Air Handling Units, while maintaining proper serviceability for all mechanical components.
  • Design flexibility: Unmatched flexibly for the system designer in the placement of the intake and exhaust ducts in the application, while maintaining the highest levels of energy recovery.

What value does a Pump-Assisted Split Loop Energy Recovery HX bring to the customer?

When a completely passive solution is not possible for all season energy recovery, this solution offers top of the market energy recovery.  

  • Plate heat exchangers require the air streams to be adjacent and intersecting at the heat exchanger and they are not volume efficient.
  • Energy wheels require the air streams to be in close proximity, they suffer from mechanical reliability issues, and they introduce cross-contamination between the two air streams.
  • Passive, heat pipe-based solutions require horizontal and near level installation for adequate performance and this is just not possible in many applications.

This solution does not have the geometric limitations of other energy recovery heat exchangers, and provides high performance and more cost savings compared to other products on the market. The ability to recover large amounts of energy over large distances all year-round with a minimal amount of energy consumption separates this technology from the rest of the field.

How will the Pump-Assisted Split Loop Energy Recovery HX change future product development in its field?

With continuous movement toward increased energy efficiency, more and more investment will be made into energy recovery products. This solution checks all of the boxes: (1) clean air, no cross-air contamination, (2) Highly efficient, two-phase heat transfer, (3) added reliability through redundancy and fluid selection and (4) high performance using two-phase heat transfer. Along with all of the performance benefits, this product removes the restrictions on hardware placement that current system designers are faced with and removes the need to trade-off system packaging and energy recovery. This will free up designers to develop new system layouts for better building air distribution and return, as well as allow for the optimization of air flow in their application, without sacrificing energy efficiency.

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