How Blown-In Insulation Helps Prevent Heat Loss in Ottawa Homes

The Science of Staying Warm: Understanding Heat Loss in Ottawa’s Extreme Climate

Ottawa winters are relentless, with temperatures routinely dropping below -20°C and wind chills making it feel even colder. Your home’s heating system works tirelessly to keep interiors comfortable, but without proper insulation, much of that expensive heat escapes into the night sky.

Heat loss occurs through three primary mechanisms: conduction (direct transfer through materials), convection (air movement), and radiation (infrared transfer). In Canadian homes, convection and conduction via air leakage account for the majority of winter heat loss—up to 40%, according to Natural Resources Canada.

Blown-in insulation excels at combating all three, creating a seamless, dense barrier that keeps heat where it belongs: inside your home. At Bison Insulation, our professional blown-in insulation in Ottawa combines high-performance materials with expert air sealing for maximum effectiveness.

Conduction: Blocking Direct Heat Transfer

How Conduction Works in Your Home

Conduction happens when heat flows through solid materials from warm to cold. In attics, this occurs through roof sheathing, joists, and any contact points. Poorly insulated spaces allow rapid conductive loss, especially on frigid Ottawa nights.

Blown-In Insulation’s Superior Resistance

Blown-in materials (cellulose or fiberglass) have high R-values—cellulose around R-3.8 per inch, fiberglass R-3.2-4.0. By achieving depths of 16-20 inches (R-50 to R-60+), they create substantial resistance to conductive flow.

Unlike batts, blown-in completely encapsulates joists and framing, preventing heat from traveling through wood (which conducts heat 10 times faster than insulation).

This uniform layer slows conduction dramatically, maintaining warmer attic temperatures and reducing the burden on your furnace.

Convection: Stopping Air Movement and Loops

The Hidden Danger of Convective Currents

In loosely insulated or empty attics, air circulates freely: warm air rises, contacts the cold roof deck, cools, and sinks—creating convection loops that continuously carry heat upward.

Gaps in batt insulation exacerbate this, allowing air to flow around and through the material.

How Dense Blown-In Insulation Halts Convection

Blown-in insulation is installed at precise densities—cellulose at 3.5-4 lbs per cubic foot—forming a matrix that traps air pockets without allowing movement. This eliminates convective loops entirely.

The result: stagnant air within the insulation acts as an additional barrier, preventing heat from cycling out of your living space.

In Ottawa’s windy winters, this convection control is crucial for maintaining consistent indoor warmth.

Air Leakage and the Stack (Chimney) Effect

The Powerful Stack Effect in Winter

Warm air naturally rises, creating positive pressure at the top of your home and negative pressure below. This “stack effect” draws cold outside air in through lower leaks (doors, windows, and outlets) while expelling heated air through upper leaks (attic hatches, recessed lights, and plumbing penetrations).

In tall or leaky Ottawa homes, this can exchange indoor air multiple times per hour, wasting enormous energy.

Comprehensive Air Sealing with Blown-In Installation

Effective insulation requires air sealing first. Professionals identify and seal:

• Top plates where walls meet attic
• Wire and pipe penetrations
• Recessed lighting (with fire-rated covers)
• Attic hatch weatherstripping
• Chimney and flue chases

Blown-in material then covers these seals, creating an airtight envelope. This breaks the stack effect, stopping conditioned air from escaping and cold drafts from entering.

Many homeowners pair this with targeted spray foam insulation in Ottawa for stubborn leaks like rim joists.

Thermal Bridging: Eliminating Heat Highways

What Are Thermal Bridges?

Framing members (joists, studs, rafters) conduct heat much faster than insulation. In batt-insulated spaces, these “bridges” remain exposed or partially covered, allowing heat to bypass insulation entirely.

Studies show thermal bridging can reduce effective R-value by 15-50% in framed assemblies.

Blown-In’s Complete Coverage Solution

Loose-fill insulation flows over and around all framing, fully encapsulating wood members. This eliminates direct conductive paths, ensuring heat must pass through the insulating material.

The monolithic layer created by blown-in insulation minimizes bridging far better than batts, delivering closer to theoretical R-value performance.

Radiation: Reducing Infrared Heat Loss

Radiant Heat Transfer in Attics

Even without air movement, heat radiates from warmer surfaces (like your ceiling) to colder ones (roof deck). In winter, this adds to overall loss.

Reflective and Emissivity Benefits

While blown-in isn’t primarily radiant barrier, dense cellulose reduces emissivity by covering surfaces completely. Some installations include radiant foil on attic hatches for enhanced reflection.

The primary radiation control comes from maintaining warmer ceiling surfaces through reduced conduction and convection.

Real-World Heat Loss Reduction in Ottawa Homes

Quantifiable Savings

Properly installed blown-in insulation to R-60 can reduce attic heat loss by 70-90%. Combined with air sealing:

• Total home heat loss reduction: 25-40%
• Annual heating cost savings: $500-$1,500 (depending on home size and fuel type)
• Payback period: 4-8 years

These figures align with Energy Star and NRCan data for Zone 6-7 climates like Ottawa.

Preventing Secondary Issues

Reduced heat loss also prevents:

• Ice dams from uneven roof melting
• Moisture condensation in attics
• Overworked HVAC systems

If existing insulation is damaged, start with insulation removal in Ottawa for optimal results.

Why Ottawa’s Climate Demands Superior Insulation

Unique Challenges of Our Continental Climate

Extreme temperature swings, high humidity, heavy snow loads, and strong winds make Ottawa particularly vulnerable to heat loss. Older homes (common in Glebe, Westboro, or Orleans) often have minimal original insulation.

Modern codes require R-60 attics, but many properties fall far short.

Blown-In’s Ideal Characteristics for Local Conditions

• Seamless fill adapts to irregular older attics
• Dense packing resists wind-driven air infiltration
• Moisture-handling properties (especially cellulose) combat humidity
• Quick installation minimizes winter disruptions

For whole-home protection, consider combining attic work with floor insulation in Ottawa to stop heat loss from below.

The Professional Installation Difference

Maximum heat loss prevention requires expertise:

• Accurate R-value calculations
• Proper ventilation maintenance (baffles)
• Thorough air sealing before blowing
• Uniform density and depth
• Post-installation verification

Bison Insulation’s certified teams deliver these details consistently—see our full attic insulation services in Ottawa.

Long-Term Benefits Beyond Heat Retention

Effective insulation provides:

• Even room temperatures year-round
• Reduced summer cooling costs
• Better soundproofing from dense material
• Lower carbon footprint
• Increased home durability and value

Conclusion: Keep Your Heat (and Money) Where It Belongs

Understanding the science of heat loss reveals why blown-in insulation is the gold standard for Ottawa homes. By addressing conduction, convection, air leakage, and thermal bridging simultaneously, it creates a robust thermal envelope that keeps you warm through the harshest winters.

Don’t let another season’s heat vanish through your attic. Professional installation delivers measurable savings, comfort, and protection.

Contact Bison Insulation today for a free evaluation. Visit our homepage to explore solutions and start saving this winter.

Your warmer, more efficient home starts with better insulation.