The York® Sun Choice rooftop units deliver value from project start to finish. The 15- to 27.5-ton units exceed Department of Energy (DOE) 2018 guidelines by up to 25% and already surpass future DOE 2023 part-load standards by almost 10%, reducing energy consumption and operating costs. A lightweight design and direct replacement footprint offer ease of installation for both new product and retrofit applications to reduce up-front costs. These RTUs also feature multiple airflow strategies, including constant volume, IntelliSpeed fan control, VAV, and continuous-reset single-zone control. They also offer a wide range of gas heat options, including full-modulation gas heat with a 2.85:1 turndown ratio and 1% incremental change of heating capacity. Outdoor air options include factory- and field-installed versions of low-leak damper economizers, constant-volume-powered exhaust, and modulating-powered exhaust.