Definition — what 'no ductwork' actually means
Older Toronto and Scarborough homes typically fall into three categories: boiler-heated with cast-iron radiators, boiler-heated with baseboard convectors, or (rarely) hydronic in-floor. All three provide reasonable heating but no cooling and no filtration.
Adding a conventional forced-air AC to these homes requires running new ductwork — usually a multi-week interior renovation with drywall cuts and framing changes. Most homeowners choose a different path.
When each option fits
Multi-zone ductless mini-split: one outdoor condenser feeding 2-4 indoor heads placed strategically (main living area, master bedroom, second-storey hallway). No ductwork required; each head has independent thermostat control; delivers heating and cooling.
High-velocity mini-duct system: small (~2-inch) flexible ducts snake through closet walls and existing chases to deliver conditioned air through discreet ceiling outlets. Higher install cost but preserves plaster and radiators.
Hybrid: keep the boiler for winter heating (or switch to a modern condensing boiler), add multi-zone ductless mini-splits for cooling and shoulder-season heating. Common Toronto solution.
- Straightforward: multi-zone ductless mini-split (+ existing boiler retained)
- Preserve interior finishes: high-velocity mini-duct system
- Full modernization: keep boiler, add multi-zone mini-splits
Failure modes — the classic century-home mistakes
Ripping out the boiler and radiators to install a central forced-air furnace and AC — often disruptive and destructive of original interior finishes. The radiators are usually the better heater in Ontario winters anyway.
Installing a portable window AC in the master bedroom as a 'temporary' fix that stays for a decade — expensive on electricity, noisy, and leaves other rooms uncomfortable.
Choosing a ductless mini-split installer who doesn't understand line-set aesthetics — nothing damages a century home's exterior faster than three white PVC line-set covers running down the front facade. A skilled installer routes line-sets discreetly.
Proof — cost and complexity
A multi-zone ductless mini-split for a 1,500-sq-ft two-storey Toronto home typically runs $10,000-$18,000 installed depending on head count, brand, and line-set complexity. High-velocity mini-duct systems typically run $25,000-$40,000 for the same house.
Both preserve the boiler and radiators. Both eliminate the ductwork-installation drywall carnage. Both make a century home dramatically more comfortable in July.
Action — Metroheat's century-home approach
We walk the home before quoting — line-set path is 60% of the aesthetic result on a ductless install. Our installers place condensers where they won't damage the exterior, route line-sets through interior chases where possible, and use paintable line-set covers on required exterior runs.
Call (416) 283-5698 or visit /contact for a century-home HVAC assessment.