Packaged heating and cooling rooftop units (RTUs) are widely utilized for space conditioning low-rise buildings and are major energy consumers in the commercial and institutional sectors. Advances in both cooling and heating technologies create the need for a better understanding of RTU energy savings potential. The objective of this study is to complete a technical and market assessment of current and emerging RTU advanced technologies to determine gas and electricity savings potential compared to current baseline operation for Canadian climates and select building archetypes.
Based on a review of applicable building codes and a technical assessment of emerging and commercially available RTU technology, six advanced energy-efficient RTU upgrade options were identified as potentially viable technologies for colder climates. EnergyPlus modeling was used to determine the energy use impacts of the selected options for five prototype buildings (Small Office, Medium Office, Strip Mall, Stand-Alone Retail “Big Box” store, and Primary School) in eight Canadian locations. An economic assessment was completed for each archetype to establish the viability of promoting these options through a utility energy efficiency program. The RTU upgrade options for colder climates with the most cost effective replacement and retrofit applications for the select building archetypes were identified. Market potential for each advanced RTU option was estimated for both replacement and retrofit installations.
Keywords: Packaged Rooftop Units, RTUs, Demand Control Ventilation, DCV, Energy Recovery Ventilation, ERV, Variable Frequency Drive, VFD, Economizer, Condensing Heating, Commercial Buildings, Institutional Buildings.