The blower door test is a critical aspect of certifying a home as a Passivhaus

It is essentially an airtightness test that measures the hermetic sealing of a building. This is how it works and why it's important for Passivhaus certification:

Purpose: The primary goal of the blower door test is to ensure that the house can maintain a consistent and controlled indoor environment without excessive energy consumption. It tests the effectiveness of the home's insulation and airtightness, critical factors in minimizing heating and cooling needs.

Process: During the test, a special fan (blower door) is mounted into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows back into the house through unsealed cracks and openings, allowing the tester to measure the air infiltration rate.

Hermetic Sealing: A key feature of Passivhaus design is its almost complete hermetic sealing to prevent unwanted air leakage. The blower door test quantifies how well the building envelope is sealed against air infiltration, a crucial factor in reducing the energy needed for heating and cooling.

Efficiency Standards: For a building to pass as a Passivhaus, it must meet specific air tightness criteria, demonstrating that it does not exceed a certain rate of air changes per hour (ACH) at a standardized pressure difference. This is a quantitative measure of the building's airtightness.

Implications: A successful blower door test indicates that the house is well-insulated and sealed, which not only reduces energy consumption but also improves comfort by eliminating drafts and maintaining a stable indoor temperature and humidity level.

Cool and Warm Seasons Performance: A well-sealed house, as confirmed by the blower door test, ensures minimal heat escape during winter and reduces unwanted heat ingress during summer, leading to a more comfortable living environment year-round.

For La Mer, during its blower test, a smoke machine was utilized to identify air leakage points around windows and other openings. This practical step was integral to ensuring the home's adherence to Passivhaus standards, highlighting its superior energy efficiency and sustainability.