What is the best bathroom ventilation option for Ottawa homes?

The best bathroom ventilation for Ottawa homes is a properly sized exhaust fan (minimum 50 CFM for most bathrooms) that vents directly outside, not into the attic or soffit. Given Ottawa's cold winters and humid summers, proper ventilation is critical to prevent mold, moisture damage, and ice damming issues.

Exhaust fan sizing is crucial for Ottawa's climate. Calculate 1 CFM per square foot of bathroom space, with a minimum of 50 CFM for bathrooms under 50 square feet. For larger bathrooms or those with jetted tubs, increase to 100-150 CFM. The fan should run for 30 minutes after showering to properly remove moisture - consider installing a timer switch or humidity-sensing fan that automatically shuts off.

Ductwork requirements in Ottawa are particularly important due to our extreme temperature swings. The exhaust must vent directly through an exterior wall or roof - never into the attic, soffit, or crawl space. Use insulated rigid ducting when possible, and ensure the exterior vent has a proper damper to prevent cold air infiltration. In Ottawa's climate, inadequately vented bathroom moisture can cause ice buildup in attics during winter, leading to water damage when it melts.

Additional ventilation considerations for Ottawa homes include installing a makeup air source if you're adding powerful exhaust fans, especially in newer, tightly sealed homes. Some homeowners benefit from heat recovery ventilators (HRVs) integrated with their bathroom exhaust, which is particularly effective in our climate where we're heating homes 6+ months per year. This recovers heat from the exhaust air while still removing moisture.

Installation requirements under the Ontario Building Code specify that bathroom exhaust fans must be on a dedicated circuit if over 300 watts, and the switch must be accessible but not within the bathtub/shower area. All electrical work requires ESA permits and should be done by a licensed electrician.

Professional installation is recommended because proper ductwork routing, exterior wall penetration, and electrical connections are critical for both performance and preventing moisture issues that could cost thousands in repairs. A poorly installed fan can actually make moisture problems worse by creating negative pressure that draws humid air from other areas.

For a comprehensive bathroom renovation including proper ventilation design, contact Justyn Rook Contracting for a free consultation to ensure your ventilation system works effectively in Ottawa's challenging climate.