Temperature maintenance losses often account for around 30% of total thermal loads in centralized domestic hot water systems in multifamily buildings (but can be as high as 60%). Correction of these omnipresent recirculation inefficiencies in high-rise multifamily buildings has direct implications...

Heat pump space conditioning and water heating can greatly reduce energy consumption compared to existing electric resistance or natural gas combustion options. Requirements for electrical service upgrades add cost and installation delays for customers considering retrofit heat pumps. Anywhere from...

Current California Public Utilities Commission CPUC regulations limit the use of Normalized Metered Energy Consumption (NMEC) as a savings platform to three use cases: commercial buildings, industrial sites enrolled in a Strategic Energy Management (SEM) program, and industrial sites with...

The project team proposes to conduct a field demonstration project that will seek to install intelligent power management technologies (IPMTs) (e.g., smart electrical panels, smart circuit breakers/relays) in manufactured housing with limitations in both customer-side and utility-side electric...

Transcritical carbon dioxide (TC CO2) is emerging as the preferred low Global Warming Potential (GWP) option for commercial refrigeration systems in supermarkets and grocery stores. The unique system architecture and operating characteristics of CO2 make it difficult to model because these systems...

High humidity poses a significant challenge in modern fully enclosed greenhouses and state-of-the-art vertical farming setups, fostering the growth of fungal diseases such as botrytis and impeding the plant transpiration process causing adverse impacts on plant health and growth. One study...

Water heating accounts for 40 percent of natural gas consumption in the residential sector, representing 7 percent of the state’s total GHG emissions (E3 2019). Water heating energy use in multifamily buildings with 5 or more units accounts for 32 percent of total energy use based on a 2015...

Standard designs for large commercial buildings rely on separate gas-fired hydronic heating and chilled water loops. This technology has slowly been refined with incremental energy efficiency improvements over several decades. The HVAC industry has not yet had enough time to establish how to serve...

Air-to-water heat pumps (AWHPS) have been gaining traction worldwide in countries where hydronic heating is the predominant HVAC option., With the United States increasing national focus on decarbonization of the building sector, the AWHPs market still trails behind other more popular HVAC options....

This proposed CalNEXT project will develop a test method to validate that control programming is consistent with the control sequences in ASHRAE Guideline 36 (G36) High-Performance Sequences of Operation for HVAC Systems. The eventual goal is for the test method to evolve into an ASHRAE standard...