Does running my fireplace all winter make my Ottawa home too dry and what does a humidifier setup cost?

Running your fireplace all winter in Ottawa can absolutely contribute to excessive dryness in your home, though the relationship is more complex than people usually assume — it depends on how much you use it, what type of fireplace you have, and how well your home is sealed.

Why fireplaces dry out Ottawa homes

An open masonry fireplace is essentially a powerful exhaust fan that pulls warm, humid indoor air up the chimney and exhausts it outside, replacing it with cold, dry outside air that your heating system then has to warm up. This process, called "exfiltration," is the primary dryness culprit. A wood-burning fireplace operating at typical efficiency removes roughly 500 to 800 cubic feet of conditioned indoor air per hour through the chimney — that is a massive volume of humid air being constantly replaced by the ultra-dry Ottawa winter air (which has humidity levels as low as 5 to 10 percent when heated indoors). If you run your fireplace frequently throughout January, February, and March, you are actively pulling moisture out of your home.

Gas fireplaces, especially direct-vent models, are better in this regard. A direct-vent gas fireplace draws combustion air from outside through a sealed pipe, so it does not pull conditioned indoor air up the chimney the way a wood-burning fireplace does. However, even gas fireplaces create some dryness because the combustion process itself produces dry heat and because any fireplace use increases overall air circulation through your home's mechanical systems.

The real dryness problem in most Ottawa homes is not actually the fireplace — it is winter heating itself. When you heat cold outdoor air from -25 degrees Celsius (which might have an absolute humidity of 1 gram of water per cubic metre) indoors to +21 degrees, the relative humidity plummets to 10 to 20 percent even without a fireplace running. This is a thermodynamic reality of Ottawa winters, and it affects every home in the city, fireplace or not. That said, running a fireplace frequently does make an already-dry situation worse.

Health and comfort impacts

Indoor humidity below 30 percent is genuinely uncomfortable — it causes dry skin, chapped lips, sinus irritation, and respiratory discomfort, especially for children and people with asthma or allergies. Extremely low humidity (below 20 percent) also stresses wooden furniture, hardwood floors, and musical instruments by causing them to shrink and crack. Most people feel most comfortable at 35 to 50 percent relative humidity.

Humidifier costs in Ottawa

A whole-home humidifier system integrated into your forced-air furnace is the most effective solution if you have ducted heating. Installation typically costs $1,500 to $3,500 including the unit, labour, ductwork connections, and a humidistat control. Popular models include the Aprilaire 700 (around $800 to $1,200 installed) and Honeywell HE360 (similar price range). These systems add moisture directly to the air flowing through your furnace, maintaining consistent humidity throughout the house. Running cost is minimal — just the cost of water going down the drain plus a small amount of electricity.

Portable ultrasonic or evaporative humidifiers cost $150 to $600 for decent-quality units and work well for individual rooms, but they require daily water refilling and maintenance, and they do not humidify the whole home effectively. They are useful as supplemental devices in bedrooms or sitting rooms where you spend the most time.

Practical steps to address winter dryness without major expense

Before investing in a whole-home humidifier, try these lower-cost strategies: run your fireplace less frequently — use it for ambiance and supplemental heat on weekends rather than every evening; ensure your fireplace damper is fully closed when the fire is completely out (the damper should never be left open overnight or when the fireplace is not in use, as this creates continuous exfiltration); use a direct-vent gas fireplace instead of wood-burning if you are planning a new installation, since it will have far less impact on home humidity; improve air sealing around doors and windows to reduce infiltration of dry outside air, though this is a larger project; and hang damp towels in living areas or run a small portable humidifier in your bedroom at night.

Plants also help — they release moisture through transpiration. A collection of houseplants in rooms where you spend the most time will modestly improve humidity without any cost beyond watering them.

The real solution for serious fireplace users

If you plan to use your fireplace as a significant heating source throughout the winter — burning a wood stove 6 to 8 hours daily or running a gas fireplace multiple hours every evening — installing a whole-home humidifier becomes far more worthwhile. The investment of $1,500 to $3,500 is reasonable insurance against the respiratory discomfort, skin irritation, and potential damage to furnishings and home materials that accompany Ottawa's brutal winter dryness. Get a quote from an HVAC contractor who can assess your specific furnace setup, ductwork, and home size to recommend the right capacity humidifier for your needs.

If you are looking to connect with an experienced HVAC or fireplace installer in Ottawa who can advise on both fireplace selection and humidity management, you can browse local contractors through the Ottawa Construction Network directory at justynrookcontracting.com/directory.

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Looking for experienced contractors? The Ottawa Construction Network connects Ottawa homeowners with qualified professionals:

• Homeupgraders
• RenoMotion Inc.
• Innovation Concrete Grind & Polish
• Coliseum concrete & interlock
• Vanguard Environmental