This project is a field prototype to evaluate the efficiency, cooling performance, and load shifting/demand flexibility, of a desiccant enhanced indirect evaporative cooling commercial packaged rooftop unit with integral energy storage designed by Blue Frontier and previously laboratory tested by the National Laboratory of the Rockies and University of California Davis Western Cooling Efficiency Center. This tests a new class of equipment referred to by the U.S. Department of Energy as a separate sensible and latent cooling air conditioning system on a commercial building. This technology uniquely brings high performance under extreme conditions. The project includes independent evaluation, measurement, and verification services.

The equipment is designed for use as a replacement for the ubiquitous compressor-based, direct expansion, packaged rooftop equipment, found on most commercial buildings under 300,000 square feet. For this project, the packaged rooftop design is sized to deliver 2,000 cubic feet per minute of conditioned air with at least 30%, and up to 100% fresh air in the supply air stream. The unit can be used in dedicated outdoor air supply and/or return air unit applications.

One of the key differentiators is independent control of latent and sensible cooling. A novel conditioner core uses a low flow of non-corrosive liquid desiccant to dehumidify the mixed outdoor and indoor return air streams in combination with a dew-point-style indirect evaporative cooler that provides sensible cooling. The unit is designed to operate in all combinations of indoor and outdoor air, ranging from hot/humid through hot/dry. Integral thermal energy storage provides load flexibility with six hours of peak load shifting. The packaged unit includes a novel, electrically driven refrigerant heat pump with small refrigerant charge to produce low grade heat which is used to regenerate the liquid desiccant. System cooling capacity and energy efficiency increases as ambient temperature increases, eliminating the negative impact of air conditioning load during heat waves and eliminating the need for equipment oversizing to meet design day cooling loads. The technology has a high turndown ratio, eliminating partial cooling load inefficiency.

Some benefits include: reduced humidity and therefore mold risk, prolonged useful life of equipment due to a decrease in excess moisture, simple integration with existing heating, ventilation, and air conditioning and water systems, enabling greater energy efficiencies and resource loads. Implementation can lower operations and maintenance costs while expanding emote operation capabilities for installation managers. (Anticipated Project Completion - 2026)