RTU sizing by occupancy

Which rooftop size fits your
store, office, clinic or restaurant?

A clothing boutique, a dental clinic, an open-plan office, and a busy kitchen do not share the same HVAC load — even at the same square footage. Learn how Toronto Air Systems matches rooftop unit capacity to real commercial use across Toronto and the GTA.

Right size for the right use

Same square footage, different rooftop needs

Square footage alone is a weak sizing tool. A 2,000 sq ft storefront with LED lighting and moderate traffic can run comfortably on a smaller packaged unit than a 2,000 sq ft restaurant with make-up air, heat-producing kitchen equipment, and constant door openings. Clinics add sterilization equipment and high outdoor-air needs; open offices add people density and computer loads that peak mid-afternoon.

Toronto Air Systems sizes commercial rooftops for how the space operates — hours, occupancy peaks, exhaust, and glass — then confirms curb, duct static, and fuel capacity. Start with our commercial HVAC Toronto page for install and maintenance context, or keep reading for store-, office-, clinic-, and restaurant-specific cues.

If you are comparing tenant improvement quotes that simply say “put a 5-ton on it,” push for a load rationale. Oversizing hides humidity and short-cycling; undersizing shows up as afternoon callbacks and unhappy customers. Call 647 953-4252 with your use type and we will walk the numbers.

Toronto and GTA conditions are not mild-climate marketing charts. Design temperatures, humidity, older building stock, and mixed fuel strategies change how RTU Size by Building Type should be specified. We start with how you use the space — occupancy, hours, duct capacity, electrical service, and existing equipment — before recommending parts or a full replacement.

Homeowners, landlords, and facility managers call us when systems short-cycle, ice up, leave rooms uneven, spike utility bills, or fail on the first deep freeze or heat wave. Whether you need a same-week repair or a planned upgrade, we document findings and present repair-versus-replace paths with pricing you can compare.

Explore related hubs for heating, cooling, and commercial HVAC, or ask about rebates and incentives that may apply to high-efficiency equipment. Call 647 953-4252 with model numbers and symptoms so we arrive prepared.

What matters most for RTU Size by Building Type in the GTA
Right sizing, licensed gas/refrigeration work, and commissioning beat the cheapest sticker price. We verify airflow, safety devices, condensate paths, and controls so your system does not fail the first extreme week of the season. Ask us about dual-fuel, zoning, and rebate-eligible models during your quote.
Efficiency upgrades when you right-size
Replacing an aging rooftop with a correctly sized high-efficiency model can improve comfort and may qualify for incentives. We note eligible paths on your proposal — details on our rebates page.
Questions that decide your RTU size
  • Primary use: retail, office, clinic, or restaurant?
  • Peak people count and typical daily schedule
  • Kitchen exhaust / make-up air already in place?
  • Medical, dental, or lab equipment heat gains
  • South-facing storefront glass and awnings
  • Server rooms or POS closets that need dedicated cool
  • Existing rooftop curb dimensions and duct layout
  • Landlord requirements for noise, economizers, or filters
Practical sequence

How we approach RTU Size by Building Type

A structured process so you always know the next step.

01
Consult
Goals & constraints
02
Assess
On-site measurements
03
Compare
Repair vs replace
04
Schedule
Parts & access
05
Execute
Licensed install
06
Verify
Commission & teach
Load profile matters

Lower-load spaces vs. higher-load spaces

Two businesses with identical square footage can need very different rooftop tonnage.

Offices & retailRestaurants & clinics
Typical driverOccupancy & glass loadKitchen equipment or exam-room ventilation
Ventilation needsStandard fresh-air ratesOften elevated by code
Tonnage tendencyLower end of the range for the footprintHigher end, sometimes a full size up
Sizing riskOversizing from rule-of-thumb guessesUndersizing if kitchen/process load is ignored
Step by step

From walkthrough to the right packaged unit

From first call to commissioned equipment, you always know the next step, the timeline, and what is included.

01
Consultation
Tell us about your home or building, symptoms, and goals — by phone or online form.
02
On-site assessment
A licensed technician evaluates your existing rooftop unit, ductwork, and load requirements.
03
Written quote
You receive clear options, pricing, timelines, and rebate notes — no vague estimates.
04
Installation or repair
Our TSSA-licensed team completes the work to code with minimal disruption.
05
Follow-up support
We walk you through operation, warranty, and ongoing maintenance recommendations.
By building type

Rooftop solutions tailored to how you operate

We do not treat every bay the same. Equipment, ventilation, and controls follow your occupancy story.

Retail & storefront RTUs
Comfortable shopping floors with glass-heavy fronts — sized for solar gain and door traffic, not just floor area.
Commercial HVAC services →
Office rooftop packages
Open-plan and suite offices with people density, IT loads, and after-hours setback strategies.
Clinic & healthcare suites
Higher outdoor-air and filtration needs with sensitive temperature control for patient areas.
Restaurant & café systems
Coordination with kitchen exhaust, dining-room comfort, and patio spill — often the hardest GTA loads.
Tenant improvement support
TI packages with clear capacity notes for landlords, architects, and general contractors.
Repair, replace & maintain
Keep the right-sized unit reliable with diagnostics, seasonal service, and documented reports.
Book a site visit →
Related services

Explore the commercial service line behind this guide.

01
Commercial HVAC Toronto
Load calculation, install, and service for retail, offices, and restaurants.
View commercial HVAC →
02
Contact us
Share your floor plan or current unit specs for a written sizing quote.
Request a quote →
FAQ

Rooftop size by business type — FAQ

Often yes. Kitchen heat, exhaust, make-up air, and high occupancy push dining spaces harder than dry-goods retail. Some sites need dedicated kitchen make-up and a separate dining RTU rather than one oversized package.
Account for higher outdoor-air rates, equipment heat, and comfort expectations in treatment rooms. Filtration and zoning matter as much as raw tons. We review floor plans and equipment lists before recommending capacity.
Sometimes, if schedules and loads are similar and duct design allows balance. Very different uses (e.g., kitchen + quiet office) usually need separate systems or strong zoning. We flag that early so you do not buy the wrong curb unit.
Short cycling, clammy air, hot/cold spots, and higher wear on compressors. Bigger is not automatically better — especially in humid GTA summers.
Many do, for free cooling in shoulder seasons and code-driven outdoor air. We specify economizers when they pay back and when the existing curb/ductwork can support them.
Toronto Air Systems — call 647 953-4252. Share use type, drawings, and landlord constraints; we return a written rooftop recommendation.
Visit our commercial HVAC Toronto service page for install, repair, and maintenance coverage across the GTA.
Cost depends on equipment capacity, brand, duct or piping complexity, electrical/gas upgrades, and whether you repair or replace. We provide written quotes after a site assessment so you can compare options fairly. Call 647 953-4252 for a visit.
Yes. We are based in North York at 132 Cartwright Ave and regularly serve Toronto, Mississauga, Vaughan, Markham, Scarborough, Etobicoke, Brampton, and nearby communities.
Yes. Gas and refrigeration work is performed by TSSA-licensed technicians. We follow Ontario code practice for venting, refrigerant handling, electrical disconnects, and condensate management.

Get an RTU size that matches how you operate

Tell us store, office, clinic, or restaurant — we will size and quote honestly. 647 953-4252.