What is the best duct material?

Sheet metal ducts are generally the best choice for most residential HVAC systems, offering superior durability, airflow efficiency, and longevity compared to flexible or fiberboard alternatives.

Sheet metal ducts, typically made from galvanized steel or aluminum, provide the smoothest interior surface for optimal airflow with minimal resistance. They don't sag over time like flexible ducts, maintain their shape for decades, and are less prone to damage from rodents or physical impact. Metal ducts also don't harbor mold or bacteria as readily as other materials, making them the healthiest long-term choice for indoor air quality.

Flexible ducts are commonly used for short runs to individual rooms because they're easier to install around obstacles and cost less upfront. However, they have higher airflow resistance, can develop kinks or sags that restrict airflow, and typically need replacement every 10-15 years. When flex duct is used, it should be properly supported every 4 feet and kept as straight as possible.

In Ottawa's climate, insulated metal ducts are particularly important for runs through unconditioned spaces like crawl spaces or attics. The extreme temperature swings we experience here make proper insulation critical for energy efficiency and preventing condensation issues. Many Ottawa homes built in the 1980s-2000s have flex duct systems that are now due for replacement with more efficient metal ductwork.

Professional installation is crucial regardless of material choice. Poorly sealed or sized ducts can reduce HVAC efficiency by 20-40%, leading to higher energy bills and comfort issues. TSSA requirements may apply to ductwork modifications, especially when connected to gas furnaces.

For a comprehensive ductwork assessment and recommendations specific to your Ottawa home, consider having a licensed HVAC technician evaluate your current system's performance and efficiency.