Whole Building Airtightness Testing

Whole Building Airtightness Testing (WBAT), often referred to as “blower door testing”, is at the forefront of building performance verification.  Building airtightness is critical, as it impacts energy usage, indoor air quality, moisture control, durability and more. Blower door testing has been adopted widely in residential codes for years and has gained considerable momentum in commercial space in recent years, with mandates by many jurisdictions, government/military projects, building certification programs, and building owners.

The common misconception in the commercial construction space is that WBAT is typically only a requirement for high-performance building construction. It will soon be required for all new construction, as the benefits reach far beyond energy efficiency.  The industry is responding, and the building code is rapidly changing. It will no longer be limited to residential construction, isolated “early adoption” jurisdictions, government, and high-performance building projects. Don’t fear the change. SBP is here to help!

Critics commonly express that the test happens “too late” to correct performance issues. Don’t be afraid! There are many ways to correct issues to meet airtightness requirements at the end of the project, without major deconstruction. This should not be an excuse to avoid WBAT. That said, finding the concealed issues before they cause catastrophic failures is paramount. More comprehensive rework now may save thousands or even millions of dollars in extensive remediation efforts, tenant displacement, or having to stop building operation. WBAT is the only functional performance test that can evaluate the integrity of the completed building enclosure. Conversely, if you are dealing with a building that has performance issues, SBP can investigate and help determine causation with WBAT and diagnostic air leakage site detection techniques, including infrared thermography.

Also see SBP Building Enclosure Group, Building Enclosure Consulting and Building Enclosure Commissioning (BECx) service offerings for more comprehensive consulting service offerings and additional information. 

If your team or project is apprehensive about meeting performance targets for WBAT or simply wants to learn more about WBAT, consider SBP as a trusted partner to guide your team to a successful test and project.

———-

Value Proposition

• Quality Assurance (QA)/Quality Control (QC): Requiring/specifying WBAT has a big impact on project QA/QC processes. FEAR OF FAILING the test tends to lead to increased focus on the building enclosure from the design and construction teams. More robust QC practices are typically implemented to include more trade coordination meetings, coordinated shop drawings, construction observation and testing, etc. to ensure the project meets the performance target for WBAT.
• Durability and Water Damage Mitigation: When designing to meet airtightness goals, water control is also typically addressed as well by reviewing the building enclosure environmental control layers for continuity. A building with favorable airtightness performance will be more resistant to moisture, which can cause damage to the building structure and finishes. Water control issues are not good for any party involved with the project. WBAT can mitigate this risk which in turn helps to increase durability and the lifespan of the building.
• Diagnose Performance Issues: Qualitative procedures like ASTM E1186 infrared thermography and smoke testing, typically performed as part of the WBAT protocol, offer a last chance to find defects in the building enclosure at substantial completion or before warranty period is over.
• Sustainability and Energy Performance: Uncontrolled air leakage can be up to approximately 30% of building energy usage. Verification of performance against energy model is key to ensuring the building performs as intended and required to meet sustainability goals.
• Indoor Air Quality: Airtightness can allow for a more effective ventilation strategy to control moisture, indoor/outdoor pollution, microbial growth, etc. Modulate ventilation through ventilation systems (with energy recovery preferred) versus “natural ventilation” that is uncontrolled/unpredictable.
• Mechanical System Sizing: By adding/verifying a performance target, the designer may be able to decrease size of mechanical equipment. There can be a reduced initial cost and long-term operating cost when accurate assessment of airtightness is accounted for in design and verified for the building.
• Thermal Comfort: Improve control over space temperature/humidity.

Sustainable Building Partners (SBP), Building Enclosures Group has staff with over a decade of residential and large building whole building airtightness (“blower door”) testing experience with all building types and sizes. We are among the industry leaders in the blower door testing space. Our involvement with Air Barrier Association of America (ABAA), specifically the Whole Building Airtightness Testing Task Group has allowed SBP staff to become integral to the review and development of the ABAA, Whole Building Airtightness Technician Program for large buildings. SBP staff are part of select group of experts that are qualified as trainers for the ABAA training program.

———-

Industry Test Standards:

• ASTM E779, Standard Test Method for Determining Air Leakage Rate by Fan Pressurization
• ASTM E3158, Standard Test Method for Measuring the Air Leakage Rate of a Large or Multizone Building
• The United States Army Corps of Engineers Air Leakage Test Protocol for Building Envelopes
• ASTM E1827, Standard Test Methods for Determining Airtightness of Buildings Using an Orifice Blower Door
• ASTM E1186, Standard Practices for Air Leakage Site Detection in Building Envelopes and Air Barrier Systems
• ISO 6781, Thermal Insulation Qualitative Detection of Thermal Irregularities in Building Envelopes – Infrared Method
• ISO 9972 Thermal Performance of buildings – Determination of air permeability of buildings – Fan pressurization method
• ASTM C1060, Standard Practice for Thermographic Inspection of Insulation Installations in Envelope Cavities of Frame Buildings