DOE: Driving Change Around Energy Efficiency

The U.S. Department of Energy (DOE) sets minimum cooling efficiency standards for rooftop units (RTUs), as well as the energy-efficiency standards for the gas-fired furnaces that are often used in RTUs. Beyond that, the DOE can also mandate that each state update its commercial building codes to meet specific requirements, including ones like ASHRAE/IESNA Standard 90.1.    

DOE Support of Standard 90.1 Creates New Expectations 

Rooftop units servicing large, open areas are usually set up with either constant volume (CV) or single-zone, variable-air volume (SZVAV) control logic. In simple terms, a CV system supplies the same amount of air across the occupied space, while an SZVAV varies the airflow to match the system capacity to the room load. With the energy-efficiency gains made possible by SZVAV systems in a variety of applications, requirements for SZVAV were added to the 2010 edition of ANSI/ASHRAE/IESNA Standard 90.1, “Energy Standard for Buildings Except Low-rise Residential Buildings.” Recognizing the energy-savings potential, the DOE further mandated that each state update its commercial building codes to meet or exceed Standard 90.1, and it maintains a database showing the minimum adoption level required by state.

Two New Standards Push the Industry

Standard 90.1 and the influence of the DOE continue to drive improved efficiency levels in rooftop units. Touted as the “largest energy-saving standard in history,” in 2015 the DOE announced their Advanced RTU Campaign, which raised RTU efficiency requirements by 13%, effective January 2018. Then, in 2016, the DOE took things further by requiring rooftop units achieve an additional 15% efficiency by 2023. YORK® has responded to the challenge by relaunching our high-performance rooftop product portfolio, which includes class-leading standard efficiency levels and units that already exceed DOE 2023 standards. Available in 3- to 150-ton capacities, these units are designed to minimize installation and operating costs and come Smart Equipment enabled. Each roof-mounted package unit combines an exceptional combination of efficiency, performance and comfort. 

The impact of DOE mandates is just one of many factors bringing about a transformation in rooftop unit design. To learn more about how DOE efficiency requirements are being met in today’s high-performing rooftop units, download your free copy of the complete Variable Air Volume (VAV) Application Guide for Rooftop Units.