What time of year is best for duct cleaning in Ontario?

There is no wrong month to clean ducts in Ontario, but two windows suit the climate best: early autumn, before the furnace starts for the winter, and early spring, after the heating season ends. Both put a clean system at the start of a long stretch with the windows shut. An event matters more than the calendar, though. If you have just renovated, just bought the house, or found mould or pests, the best time is now. This guide goes season by season, then covers the events that override the season and how far ahead to book.

The year at a glance

Early autumn: before the furnace starts

From autumn to spring a GTA house runs with the windows shut and the furnace blower moving the same air through the same ducts most days. Whatever is sitting in the system at the first start gets circulated for months. Cleaning in September or October removes the pollen that came in over the summer and the dust that settled while the system was on cooling.

It also deals with a familiar complaint. A burning or dusty smell at the first furnace start of the year is dust on the heat exchanger and in the supply runs warming up. Our guide to smells from the vents covers that one and the four other common causes.

Winter: yes, it can be done

People often assume duct cleaning has to wait for warm weather. It does not. Our crews work year-round. The house is not open to the weather for more than a hose through one door, and the system is sealed at the registers while we work. The furnace is switched off during the cleaning, which takes about 1.5 hours for a house, so the house cools a little and warms back up afterwards.

Two practical points for a winter visit. Clear the snow from the driveway and the path to the door nearest the furnace, because the truck has to park close and the hose runs from it into the house. And keep pets in a closed room, since that door stays ajar.

Early spring: after the heating season

By April the returns and the blower have had a full winter of closed-window air drawn through them: fabric fibre, skin, hair, pet dander and whatever came in on boots. Cleaning in spring removes that before the air conditioner starts. It matters in summer because the cooling coil runs wet, and a dusty, damp coil is where a musty smell at start-up comes from.

Summer: fine, with one caution

Summer is as good a time as any for the ducts themselves. The caution is renovations. If a kitchen, basement or floor project is planned, clean afterwards. The order that works is: all dusty trades finished, the final construction clean done, then the ducts, then move the furniture back. Cleaning first means paying twice. Our guide to duct cleaning after a renovation explains why drywall dust is the worst case.

If someone in the house has allergies

Clean before the season that bothers you most. Late winter, ahead of tree pollen, suits spring sufferers. Mid-summer, ahead of ragweed, suits late-summer sufferers. Cleaning removes what has already collected in the system. It does not stop pollen coming in through doors and windows, so pair it with a fresh filter. Our guide to allergies and duct cleaning is honest about what it can and cannot do.

Events that matter more than the month

The US Environmental Protection Agency recommends cleaning "on an as-needed basis," not on a schedule. These are the needs that should not wait for a convenient season:

• A renovation has just finished. Every blower cycle spreads a little more fine dust through the house.
• You have just bought a resale house. Before the furniture arrives is the easiest time. See duct cleaning when you buy a house.
• You have found evidence of mice or insects in the ducts. Fix the entry point, then clean.
• There is visible mould or a water leak has reached the ductwork. Fix the water first. Cleaning without that only buys a few weeks.
• Dust puffs out of the registers when the blower starts. That is loose material in the supply runs.

The full list is in 8 signs your ducts need cleaning.

What does not change with the season

• The price. Our price list is the same all year: $399 to $499 for a house with one furnace, by size, and $449 flat for a condo suite, before HST. See the price list.
• The work. The same 12 steps in January as in July.
• The hours. Seven days a week, 6:00 AM to midnight.
• The filter. Whatever the month, put a new furnace filter in the day the cleaning is done, so the clean system starts with a clean filter.

How far ahead to book

The booking page shows the open dates for the next three weeks, with arrival times at 8:00 AM, 10:30 AM and 1:00 PM. If none of those times work, pick the option to agree a time by phone. If you are aiming for a particular week, such as the one before a move or the one after the painters leave, book as soon as the date is firm.

How often, regardless of season

For most households we recommend every three to five years, and every two to three with shedding pets or allergies. The reasoning is in how often to clean your ducts in Ontario.

Frequently Asked Questions

What time of year is best for duct cleaning?

Early autumn, before the furnace starts, or early spring, after the heating season. Both leave the system clean at the start of months with the windows shut. If you have just renovated, moved in, or found mould or pests, do it now instead of waiting.

Can ducts be cleaned in winter?

Yes. Our crews work year-round. The house is open only for a hose through one door, the registers are sealed, and the furnace is off for about 1.5 hours while a house is cleaned.

Should I clean the ducts before or after turning the furnace on in the fall?

Before, if you can. Whatever is in the ducts at the first start is circulated for the whole heating season. Cleaning after the furnace has started is still worthwhile.

Is spring or fall better for duct cleaning?

Either works. Fall suits most households because the heating season is the longest stretch with the windows closed. Spring suits people whose allergies are worst in summer, and anyone who noticed a musty smell when the air conditioner started.

Does duct cleaning cost more at busy times of year?

Not with us. The price list does not change by season or by day of the week.

How often should ducts be cleaned in Ontario?

Every three to five years for most homes, and every two to three years with shedding pets or allergies. Clean sooner after a renovation or when you move into a house.