By Infinity HVAC LTD
Commercial buildings have lots of moving parts. Rooftop HVAC units are very important for keeping the inside air quality in commercial buildings. When the system works normally, nobody cares.
However, if anything goes wrong, it will impact the entire building timetable.
Among all the HVAC setups used in commercial spaces, rooftop HVAC units – commonly referred to as RTUs – remain the most common option. They sit out of sight, they’re built to handle long hours, and they keep the building’s indoor environment consistent. But many property owners don’t get a clear explanation of how these systems work or what they actually need.
This guide aims to provide a straightforward and practical understanding of RTUs, drawing on real-world field experience; no complicated engineering language – just what you should know as a commercial property owner.
1. What a Rooftop Unit Actually Does
A rooftop HVAC unit is essentially the entire heating, cooling, and ventilation system packaged into one cabinet. Everything – the blower, burners or heating elements, evaporator coil, compressor, filters, and controls – is built inside one housing.
Because the system is self-contained, installation tends to be more predictable than a split system. And since everything is on the roof, it keeps the noise, vibration, and maintenance work outside the tenant space.
For buildings with multiple units, such as plazas, multi-tenant facilities, and offices, RTUs enable each section of the building to operate independently. One tenant can adjust their temperature without affecting anyone else.
2. Why RTUs Are Popular for Commercial Buildings
Most commercial building owners choose RTUs because they address several practical issues that indoor equipment creates.
They free up interior space
No one wants to give up valuable square footage for mechanical rooms. The main reason for keeping the HVAC system in the roof is this. System maintenance is easy and less disruptive.
No interruptions are made to the daily routine when the techs are visiting the site for maintenance or inspection, because the full system is installed on the roof.
The work stays out of the way.
Why Proper HVAC Maintenance is Crucial
Accidental damages are also reduced.
Outdoor ground units are vulnerable. Rooftop units are not, which means fewer repair calls and longer equipment life.
They can handle heavy-duty use
Commercial buildings often run long hours. RTUs are built to handle that demand without struggling the way residential systems would.
This combination of durability and convenience is what makes RTUs a reliable choice for most commercial buildings in Ontario.
3. Warnings for the RTU that need attention.
Even well-built rooftop units age, and most will hint at problems long before they break down. Some of the early indicators include:
Uneven temperature across the building
Higher energy bills without a clear cause
Strange noises, especially on startup
Short cycling
Poor airflow or weak ventilation
Repeated service calls
Systems older than 12–15 years
Compared to residential HVAC units, commercial ones are more challenging. The constant struggle is not a usual case; if the system is experiencing issues more often, it might be due to the reduced energy efficiency, or it’s due to the shortened life.
4. RTU installation-Professional way
Commercial HVAC installation has more steps than people realize, and the process depends heavily on planning. Bringing a rooftop unit onto a building requires careful coordination among the HVAC installer, crane operator, and, in some cases, the city if road space is required.
Here’s the general flow of a typical RTU installation handled by Infinity HVAC LTD:
Assessment and sizing
Every job begins with evaluating the building’s load requirements. Oversizing wastes money. An undersized system will have less life, less efficiency, and more energy wastage. Selecting the right size for the system is more important than you think.
Crane scheduling
Lifting an RTU isn’t a small job. We coordinate crane availability, timing, and safe access routes to the roof.
Disconnecting the old unit
The existing RTU is safely disconnected from gas, electrical, and duct connections, then removed by crane.
Preparing the roof curb and ductwork
We check the curb for wear or damage and modify sheet metal connections if needed. This is where precise sheet metal work becomes essential.
Setting the new unit
A crane is used to lift the RTU units due to their weight. The unit is then fixed in the slot and carefully sealed.
Commissioning
A proper completion of installation includes verifying gas, pressure, air-flow level, and amount of refrigerant. A professional, rooftop HVAC installation will help the system immediately.
5. Routine maintenance increases the life of RTUs
The working of commercial HVAC systems is more complex compared to residential HVAC systems. For some commercial buildings, their HVAC system is constantly working without a break.
The continuous work makes the system wear out faster than usual. Proper maintenance will help to overcome this to an extent.
A typical maintenance visit must include:
Filter changes
Belt inspections
Cleaning coils
Checking electrical components
Lubrication of moving parts
Inspecting gas lines and heat exchangers
Testing safety switches
Verifying airflow and temperature split
Skipping maintenance is one of the main reasons energy bills creep up, and equipment fails earlier than it should.
6. When It’s Time to Replace Instead of Repair
In most cases, the system will work up to 15-20 years, with regular maintenance and service. Most systems will shut down automatically after 20 years. The complete HVAC system replacement is the best practice.
You should consider replacing an RTU when:
It’s approaching 15–20 years old
Repairs are becoming frequent
Energy bills are noticeably higher
It uses an outdated refrigerant
The building’s needs have changed
Performance is inconsistent even after maintenance
New rooftop unit models are more efficient, with cost-effective energy-efficient technology. The cost savings usually justify the upgrade.
7. Why Infinity HVAC LTD Is The Best Choice for Your Roof Top Unit
Infinity HVAC LTD brings experience in:
Commercial HVAC installation
Rooftop unit replacement
Custom sheet metal fabrication
Preventive maintenance
Diagnostics and repair
Builder and contractor partnerships
Quality workmanship and long-term reliability are our best practices.
What you should expect from us
Comparing with residential HVAC systems, if anything goes wrong with commercial systems, it will affect a whole lot of people.
You must have some basic idea about how the rooftop HVAC system works, and what measures to take for keeping the system maintained, for avoiding the frequent breakdowns.
Infinity HVAC LTD is the perfect partner for you if you are planning a new RTU system installation, maintenance, or tune-up.
