Ductwork Installation and Duct Repair in Ottawa
New ducts for basements and additions, plus sealing and balancing for the rooms that never feel right
- 5.0 · 396 Google reviews
- TSSA & HRAI approved
- 24/7 emergency service
- Family-owned since 2005
New ducts for basements and additions, plus sealing and balancing for the rooms that never feel right
- Free estimates on new installations
- Financing from $49/month (OAC)
- All makes and models serviced
Ductwork is half of your heating and cooling system
Your furnace and air conditioner make the heat and the cool air; the ducts decide where it goes. A new high-efficiency furnace or AC connected to undersized or leaky ducts will never deliver the comfort or the efficiency on its label.
Many comfort complaints in Ottawa homes are airflow problems, not equipment problems: the cold bonus room over the garage, the finished basement that never warms up, the upstairs bedrooms that reach 27 °C in July.
Oria designs, installs and repairs residential ductwork, from a few new runs in a basement renovation to a full layout for an addition. Because we also install furnaces, air conditioners and heat pumps, we look at the whole system rather than one piece of it.
Signs of a duct problem
Duct problems rarely announce themselves as duct problems. These are the symptoms that usually lead back to the ductwork.
Hot and cold rooms
Rooms more than 2 to 3 °C off the thermostat setting, especially at the end of long runs or over the garage, usually are not getting enough air.
Weak airflow at some registers
A disconnected run, a crushed flex duct or a closed damper can leave a register barely breathing while others blow hard.
Whistling, rattling or banging
Whistling grilles mean too much air through too small an opening. A bang when the blower starts is often a thin duct flexing under pressure.
Dust and musty smells
Leaky return ducts in an unfinished basement pull in dust and damp air, then blow it through the house.
Long run times and high bills
If the system runs and runs but the house never quite reaches the setting, restricted or leaking ducts are a common cause.
Hot upstairs in summer
Second floors that overheat in July often need more return air upstairs, not a bigger air conditioner.
Learn more →New ductwork for basement finishes and additions
Finishing a basement is one of the most common reasons Ottawa homes need new ductwork. Builders usually leave a few supply registers and maybe one return, which is not enough once the space becomes bedrooms, an office or a rec room.
Plan before the drywall goes up.
Supply and return runs, bulkheads and register locations are cheap to change while the ceiling is open and expensive once it is closed.
Add return air.
Every room with a door needs a path back to the furnace: a dedicated return, a jumper duct or a transfer grille. Without one, the room pressurizes and the supply barely flows.
Check the furnace capacity.
A finished basement or an addition adds heat loss. We confirm your furnace and blower can carry the extra load, or tell you plainly if they cannot.
Additions and bonus rooms.
A long run to a new addition loses air and heat. Sometimes a properly sized trunk extension works; sometimes a separate ductless unit or a radiant floor zone is the better answer.
Keep the furnace room accessible.
Don't frame walls tight around the filter slot, humidifier or HRV, so service stays easy.
Adding central air to a home without ducts
Homes heated by a boiler, electric baseboards or radiant floors have no ducts to carry cool air. That is common in older central Ottawa neighbourhoods and across Gatineau, where many homes heat with electric baseboards.
| Option | How it works | Best for |
|---|---|---|
| Ductless mini-split | Wall or ceiling heads connected to an outdoor unit by small refrigerant lines; no ducts | Most finished homes. Also heats. Single zone $3,500–$6,500, multi-zone (2–4 heads) $7,000–$16,000 |
| New ductwork with an air handler | Ducts run through closets, bulkheads or the attic to a central air handler | Gut renovations, new additions or homes where walls and ceilings are already open |
For most finished homes we recommend ductless mini-splits. They avoid opening walls and ceilings, and a cold-climate model heats as well as cools. New ductwork makes sense when you are already gutting the house or adding a level.
Where ducts must run through an unheated attic, they need to be sealed and well insulated. Otherwise they sweat and drip in summer and lose heat in winter.
Duct sizing, sealing and balancing
Good ductwork starts with numbers. We calculate each room’s heat loss and cooling load, then size supply and return runs to deliver the right airflow for the blower, instead of matching whatever size of hole is already there.
Sizing.
Undersized ducts are noisy and starve rooms; oversized trunks can leave distant rooms with weak air. Return ducts matter as much as supplies and are the most often undersized.
Sealing.
Joints and seams are sealed with mastic or foil tape rated for ductwork, not cloth duct tape, which dries out and falls off. Sealing the basement return side keeps dust and damp air out of the system.
Insulation.
Ducts in garages, attics and crawlspaces are insulated so they do not lose heat or drip condensation.
Balancing.
Branch dampers are set so each room gets its share. Many two-storey Ottawa homes do best with a winter and a summer setting: more air downstairs in January, more upstairs in July.
We confirm the result with static pressure readings. High static pressure shortens blower motor life and is a common reason a new air conditioner or furnace underperforms.
How a ductwork project works
- 1
Site visit
We look at the furnace, the existing trunks and branches, and the rooms you want to fix or add, and listen to what is wrong.
- 2
Design
We work out airflow for each room and plan the routes for supplies and returns, bulkheads and grilles.
- 3
Estimate
You get a price for the work before anything starts. Estimates on new installations are free.
- 4
Install
New runs are fabricated, hung and connected, with dampers on branch lines so the system can be balanced.
- 5
Seal and insulate
Joints are sealed with mastic or foil tape, and ducts in unheated spaces are insulated.
- 6
Balance and test
We set the dampers, check airflow and static pressure, and show you how to adjust for summer and winter.
Ductwork installation cost in Ottawa
Ductwork is quoted per project. A new supply and return for one basement bedroom is a very different job from a full layout for a two-storey addition, and access, ceiling height and finished surfaces change the labour considerably.
If you are replacing a furnace, air conditioner or heat pump, fixing ductwork at the same time is usually the most cost-effective approach, because the plenums are already being rebuilt. The same goes for a basement finish: duct changes cost far less before drywall than after.
The final price depends on your home, the equipment and the ductwork involved. Oria gives free estimates on new installations, and financing from $49/month is available on approved credit. If your upstairs is the problem, our article on why the house is hot with the AC on explains the common causes.
Frequently Asked Questions
Straight answers from licensed Ottawa technicians. Still have a question? Call us any time.
How much does ductwork installation cost in Ottawa?
Ductwork installation in Ottawa is quoted per project, because a few new runs for a basement bedroom and a full duct layout for an addition are very different jobs. Access, ceiling height, finished drywall and the number of supply and return runs all affect the price. Oria visits the home, designs the layout and gives free estimates on new installations.
Can you add ductwork to a finished basement?
Yes, but it is easier and less expensive before the drywall goes up. In a finished basement, new runs are usually hidden in bulkheads, closets or along joist bays, and sometimes a section of ceiling has to be opened and patched. If you are planning a basement renovation, have the ductwork designed before framing so supplies and returns go exactly where they are needed.
Why are some rooms in my house always hot or cold?
Uneven temperatures usually come from airflow, not the furnace or AC. Common causes are long or undersized duct runs, leaky or disconnected ducts, a missing return air path from closed rooms, closed or poorly set dampers, and rooms over garages or with large windows. A technician can measure airflow at each register and fix the cause with sealing, balancing or new runs.
Can you add central air to a house without ducts?
Yes. The two main options are ductless mini-splits, which use wall or ceiling heads and small refrigerant lines, and new ductwork run to a central air handler. For most finished homes, ductless is less disruptive and also heats. In Ottawa, a single-zone mini-split typically costs $3,500 to $6,500 installed and a multi-zone system $7,000 to $16,000.
What is duct sealing and is it worth it?
Duct sealing means closing leaks at joints, seams and connections with mastic or foil tape rated for ductwork. It is usually worth doing on accessible ducts, especially return ducts in unfinished basements and any ducts in garages or attics. Sealed ducts deliver more air to the rooms that need it, pull in less dust and help the furnace and air conditioner run efficiently.
How long does ductwork last?
Sheet metal ductwork can last for the life of the house if it stays dry and undamaged. The weak points are joints, old cloth tape, flexible duct sections and connections at the furnace, which loosen or deteriorate over time. If your ducts are decades old, it is usually a matter of sealing, repairing and resizing sections rather than replacing everything.
Should ducts be changed when I replace my furnace or add AC?
Not always, but they should be checked. Adding air conditioning or a heat pump often needs more airflow than heating alone, and older returns are frequently undersized. A technician should measure static pressure and look at the return air before sizing new equipment. Fixing a restriction at the same time as the replacement is usually the most cost-effective time to do it.
Book Service or Get a Free Estimate
Tell us what is going on and we will call you back with honest advice and a written estimate. Financing from $49/month on approved credit.
- Licensed gas & refrigeration technicians
- 5.0 stars from 396 Google reviews
- 24/7 emergency service
5.0 Stars from Ottawa Homeowners
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