The Problem

The ProblemVance Kershner acquired a vacant but formerly used automotive repair facility with the idea that he would convert it into a museum for his extensive collection of antique vehicles and American muscle cars, while also creating a space for special events.   A large, upscale diner was also built on the adjacent property.

Garages require adequate ventilation to remove motor vehicle odors and a significant quantity of outside (“fresh”) air helps mitigate odors while also providing superior indoor air quality (IAQ).  This large amount of outside air also presents a moisture removal/dehumidification challenge during warm, humid outside conditions and traditional HVAC equipment requires considerable energy to remove moisture.

The AirGreen Solution

The owner sought to deploy the AirGreen technology in order to pre-treat the requisite outside air in order to meet requirements for air circulation as well as provide dry, comfortable conditions.  In this instance, all of the outside air would be pre-cooled and dried using the AirGreen equipment prior to being circulated and further cooled by two standard rooftop air conditioning units (RTUs).  The AirGreen equipment can (and did) handle most of the cooling and dehumidification during mild weather, and the RTUs did not need to run at all.  In very warm weather, the RTUs would “kick in” to provide supplemental cooling when needed.  Furthermore, the capacity of the AHU’s were downsized as a result of the AirGreen installation, reducing some capital costs.

As one of AirGreen’s first installations, it provided a platform to demonstrate its unique capabilities, which was augmented by a full suite of IoT controls, which allow for remote monitoring and automatic adjustments from daytime to evenings and weekends, changing outdoor conditions, and whether the space would be occupied or not.

The AirGreen units were fit into two small mezzanines, which presented a considerable spacing challenge.  As the AirGreen equipment can be broken up into modular components, the designers were able to locate the AirGreen A/C and dehumidification module on the mezzanine located on top of the restrooms, and the water source heat pump and the AirGreen regenerator were located on the mezzanine located on top of a small storage area.  The dry cooler used to shed heat energy during hot weather conditions was located outside on the roof of the building, near the small RTUs.

Using AirGreen as a Heating Solution

Using AirGreen as a Heating SolutionIn addition to the cooling and dehumidification work that AirGreen accomplished, this system was also set up to reverse itself and provide heating and humidification in the winter.  By reversing the flow of chilled and hot water from the water source heat pump, the AirGreen module that was previously used to cool and dehumidify outside air during the cooling season would receive hot water instead of chilled water.  As a result, this unit would preheat and humidify cold and dry outside air prior to being distributed through the facility.  To balance the overall system, the AirGreen module that was formerly being used as a regenerator would receive the chilled water from the heat pump and offload that energy to the exhaust air stream.

Testing and comparison of this overall approach in similar outdoor cold weather conditions demonstrated that the RTUs only need to provide supplemental heating for only about 6 hours out of 54 hours of continuous operation (10.7% of the time) during a period where the average outdoor temperature was approximately 49oF while maintaining indoor conditions at 68oF.  This allowed for substantial energy savings.  We’re not sure this approach has ever been successfully demonstrated before, but it certainly works in this case.

Working With AirGreen

As this was an early-stage demonstration project, AirGreen was able to be directly engaged with the designers, the construction team, and the architect early in this project to best lay out where the AirGreen equipment should be located, while not interfering with the purpose of this facility, and to protect its unique and special vehicles.  Normally, equipment to do this work could not be split into modular components, but the AirGreen technology is designed to do just that.