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Why is air sealing important?

Leaky homes are inefficient, uncomfortable and unhealthy. Building sealing is one of the most important energy efficiency measures.
Air sealing is critical to an energy-efficient, long-lasting and healthy home
Air leakage or infiltration occurs when outside air enters the house uncontrollably through cracks, crevices and openings. Homes with more air leakage are significantly less energy efficient than well-sealed homes. They also require more powerful heating and air conditioning systems to maintain a pleasant climate in the home. These larger systems must run more frequently to keep up with temperature changes as outdoor air flows into the home.
The problem of leaky structures extends beyond how efficiently indoor climate systems work. Uncontrolled air leakage can also cause unwanted moisture to enter the building, which can cause structural damage, leading to expensive building repairs. Since moisture is predominantly carried by air currents, which account for up to 98% of all water vapor movement in buildings, air sealing your home is essential. Air infiltration also allows dust, allergens, pollutants and other airborne particles to enter the home, causing poor indoor air quality.

Reducing uncontrolled air exchange is a cost-effective way to reduce heating and cooling costs, improve building longevity, increase overall comfort and create a healthier indoor environment.

CO2 emmisions chart, energy usage chart
Thermal image shows before and after air sealing. After is much more energy efficient.

Air permeability of buildings and energy efficiency indicators are directly related

A study conducted by the Fraunhofer Institute for Building Physics in Stuttgart showed that an air-permeable building envelope can reduce the thermal insulation efficiency by as much as 4.8 times - a leaky 50m2 building required the same amount of heating as a 240m2 hermetic building.

Prevention of major construction risks

AeroBarrier helps control 3 of the 4 main risks in construction. Each of these must be anticipated to guarantee a healthy, efficient, well-built home.
Mineral wool insulation, effects of air leakage on insulation
Achieve the declared insulation U-value!
Uncontrolled air movement has various characteristics that can reduce the overall effectiveness of fiber insulation. Outside temperature, humidity and air circulation can gradually degrade your home's insulation. In addition, newly installed insulation, such as during renovation, may not perform as intended if it is exposed to uncontrolled air movement and its integrity is compromised. In fact, building tightness is often the main reason why newly built homes do not meet the calculated, intended energy efficiency. Solving this problem is very important to achieve the desired energy efficiency.
Blower Door testing in progress

How is the air permeability of buildings measured?

The air permeability of the building is one of the most important indicators of construction quality
Air leakage in a building can significantly affect energy efficiency, comfort and indoor air quality. That's why it's important to understand how well your home or building is sealed. One of the most effective methods of measuring air leakage is the Blower door test.

A blower door is a diagnostic tool used by professionals to assess the airtightness of a building. During this test, a powerful fan is temporarily installed in the front door, which creates either positive or negative pressure in the building, simulating the effects of wind or temperature differences.
As the pressure changes, the tester measures the airflow required to maintain a certain pressure difference between the inside and outside of the building. Expressed as m3/(m2h) or air exchange hour (ACH), this measurement helps determine the amount of uncontrolled air movement in a building.
Exclamation mark, building code requirement for air leakage

The current building regulations of Latvia stipulate that in all newly constructed residential and public buildings, air permeability indicators must not exceed q50 ≤ 1.5 m3/m2h (near zero energy buildings).


In contrast, the passive house standard requires an air leakage rate of no more than 0.6 air changes per hour at a pressure of 50 Pascals (0.6 ACH50).

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