Current heating, ventilation, and air conditioning (HVAC) retrofits largely focus on one-for-one equipment replacement at end of life. The objective of this project is to show that the very high efficiency (VHE) HVAC whole system approach to commercial HVAC can be successfully applied in three non-residential buildings commonly found in military facilities. Originally developed by the Northwest Energy Efficiency Alliance, VHE HVAC was tested between 2015 and 2018 in eight, rigorously-documented demonstration sites in the Pacific Northwest and achieved HVAC savings of 48%-89% and demand reductions of 20-40%. A separate project in Tarrytown, NY in 2018-19 produced similar results. In addition to energy savings, the system greatly improved ventilation and indoor air quality. A subset of the demonstration sites replaced gas heating with heat pumps, yet showed almost no increase in electrical use or peak demand.

VHE HVAC is not a specific technology, but rather a performance-based, technical specification that optimizes the entire HVAC system. Requirements include high-efficiency heating and cooling equipment, extremely high performance heat or energy recovery, complete separation of the heating/cooling and ventilation functions, and airflow segregation that limits the spread of chemicals. While the VHE HVAC concept is a whole-system optimization approach, it relies on an enabling ventilation technology that had been available in Europe for many years but was not brought to the North American market until 2016. These packaged heat and energy recovery ventilators (H/ERV) use a micro-channel counter-flow heat exchanger that reduces the ventilation portion of the heating and cooling loads by 85% or more. Under design conditions, the ventilation load can comprise more than a third of the total heating or cooling load. Thus, this level of load reduction allows a significant downsizing of the heating/cooling system—typically by 40% or more. By controlling the ventilation system based on occupancy in combination with this equipment being highly efficient to begin with, the heating and cooling system can be utilized only when necessary, significantly reducing hours of system use. The H/ERV technology also has highly sophisticated yet inexpensive controls that allow building owners and operators to know exactly how the whole HVAC system is performing minute by minute, and also allows for the remote adjustment of any parameter of system operation.

What sets the project apart is that it can simultaneously reduce energy use and improve indoor air quality without increasing demand on the grid. Technical performance will be quantified by comparing the pre-conversion building and HVAC energy use, as well as indoor air quality and occupant comfort, to the post-conversion conditions with the VHE HVAC system. These results will be converted to energy use intensity (kBtu/sf/year) so they can be compared to similar buildings. Economic benefits will be determined through a life-cycle cost analysis comparing the cost of typical HVAC replacement strategies to the actual installed cost of the VHE HVAC system. Success for this project is defined as having outcomes equivalent to or better than those documented in previous demonstrations.

HVAC accounts for 45% of energy use in commercial buildings and also drives peak grid demand. Substantially reducing HVAC energy use will significantly help Department of Defense (DoD) increase its energy efficiency and cut costs. DoD can expect to see HVAC-related energy reductions of 50% or more in applicable buildings as well as peak demand reductions of 20%-40%. Building occupants will experience greatly improved comfort and indoor air quality as a result of the installation of highly controllable ventilation systems. Applied at scale, back-up generation capacity can be reduced. (Anticipated Project Completion - 2025)