For this new K-8 school project in Arvada, Colorado, HPE provided a full HVAC & plumbing system that included a central boiler plant, rooftop units, variable air volume units, and more. HPE designed and provided the expansion compensation system for the project which included a Fulton boiler system, (10) RTUs, and VAVs.n Arvada, Colorado, HPE provided a full HVAC & plumbing system that included a central boiler plant, rooftop units, variable air volume units, and more. HPE designed and provided the expansion compensation system for the project which included a Fulton boiler system, (10) RTUs, and VAVs.