What it means
An RTU contains the heating section, the cooling section, the fans and the controls in a single cabinet. It supplies conditioned air to the space below through ductwork, and it usually sits on a roof curb that is flashed into the roofing system.
Heating is commonly by natural gas, and cooling by refrigerant coils. Newer units often include economizers, which use cool outdoor air when conditions allow.
Why it matters
RTUs are a major building system. Their capacity must match the load of the space, and a tenant change that adds people, equipment or glass can overload an existing unit. Alberta's winters also demand reliable heating and good controls.
Replacement or addition is a lifting and roofing job as well as a mechanical one. It needs a crane, a roof curb that is correctly sealed, gas and electrical connections, and coordination with the roof warranty holder.
How HSM handles it
HSM's own mechanical crew installs, replaces and services rooftop units, and our electricians make the power connections. That means one team handles the curb, the lift, the gas, the power and the controls.
Our engineering team checks unit capacity against the real load of your space before any equipment is ordered, and we flag lead times early because RTUs can take a while to arrive. We coordinate with the landlord and roofing contractor so that the roof is protected and sealed.
After installation, we start up and test the unit as part of commissioning.
What to plan for
Winter is a factor. Crane lifts, roof work and sealants depend on temperature and wind, so replacements are often best scheduled for milder months, and heat must be maintained for occupants during any shutdown.