Evaluating Air Leakage Test with Blower Door: Identifying Energy Losses in Fresh Construction
In the realm of renewable construction and renovation projects, two key methods stand out when it comes to finding energy leaks: Blower Door Tests and Thermography. Each has its unique advantages and disadvantages, but when combined, they offer a powerful tool for energy audits.
A Blower Door Test is a crucial method for quantifying the overall air leakage rate of a building. This test is most effective immediately after the airtightness layer has been created, as it's at this stage that leaks are easiest to find. It uses a calibrated fan to depressurize the building, forcing outside air through all leaks, enabling precise measurement of leakage (e.g., air changes per hour) and locating leaks by the induced airflow. This method is essential for confirming air tightness levels to meet building code requirements and is typically required for final inspections.
However, a Blower Door Test does require specialized equipment, trained professionals, and the building must be in a state ready for testing (all openings closed and sealed except the test fan panel). It measures overall leakage and localizes leaks by airflow but does not provide a visual map of temperature differences or exact leak locations without additional tools like thermal cameras.
On the other hand, Thermography, or thermal imaging, offers a visual map of leakage locations and insulation defects. It can visually identify where the leaks or missing insulation are by detecting temperature differences on surfaces. Thermography can show cold or warm spots in walls, ceilings, windows, etc., and is non-invasive and quick to use. When combined with blower door testing, pressurizing the building makes temperature differences more pronounced, making leaks easier to "see" on the thermal camera. Thermography can be used in different seasons to detect heat loss (winter) or unwanted heat gain (summer).
Thermography, however, cannot quantify the amount of leakage or airflow—only temperature differences. It may also be less accurate if temperature differences are subtle or environmental conditions are not ideal.
From a consumer advocate's perspective, a Blower Door Test can be useful at the end of a renovation to check the quality of the work done. Similarly, thermography can be beneficial for locating leaks or diagnosing insulation issues. The Association of Private Building Owners (VPB) suggests that both the Blower Door Test and thermography can be part of independent energy advice, as the airtightness of buildings is often overlooked in terms of energy efficiency.
In summary, the Blower Door Test provides precise quantitative data about overall air leakage and is often mandatory for code compliance, while thermography offers a visual map of leakage locations and insulation defects but lacks quantification on its own. Combining both methods is a common best practice as they complement each other's strengths.
Both methods have their place in ensuring energy efficiency in buildings, and their combined use is widely employed in professional energy audits to find and fix building envelope leaks effectively. While a Blower Door Test can detect even the smallest holes in a building, thermography can detect heat bridges and moisture damage on a house, but it cannot be used year-round due to temperature requirements.
References:
- Building Science Corporation
- PASSIVE HOUSE INSTITUTE US
- Association of Private Building Owners (VPB)
- Energy Saving Trust
- In light of the ongoing climate-change crisis and the need for renewable energy adoption, effective community policy and energy policy must prioritize the implementation of energy efficiency measures in buildings, such as Blower Door Tests and Thermography.
- The environmental-science community emphasizes the importance of incorporating Blower Door Tests and Thermography in energy audits for residential and commercial buildings, as they offer a comprehensive approach to identify and address energy leaks.
- As the industry transitions towards sustainable energy solutions, the financial sector should consider the long-term benefits of investing in buildings that have undergone energy audits using Blower Door Tests and Thermography, as they can significantly improve energy efficiency and reduce environmental impact.
- By enhancing the airtightness of buildings through Blower Door Tests and detecting insulation issues with Thermography, we can contribute to both the environmental-science goals of reducing energy consumption and combating climate-change and the financial sector goal of maximizing energy efficiency and savings.
