Air Barrier Performance Testing Flashcards
Generalized description of Air Barrier Testing (ABT)
High power calibrated fan(s) are utilized to induce a test pressure within the building and the corresponding flow rate is measured to determine the buildings air leakage rate.
What does ABT test?
ABT is a test of the building air barrier system continuity
What ASTM’s cover ABT and which one pertains to fan pressurization?
ASTM E779 (2010), ASTM E1827 (2011), and ASTM E1168 (2009) are standards for test methods for determining air leakage rate and air tightness of buildings and air barrier systems, but ASTM E779 is specific to fan pressurization.
What are some benefits of using ABT to identify discontinuities in air barrier systems?
- reduced building HVAC costs
- identifying appropriate mechanical systems sizes and operations
- control of moisture and mold
- reducing pollutant transport
- improved microclimate conditioning
- improved sound/acoustics
Who requires air barrier testing?
- USACE (Army Corps of Engineers)
- NVAFAC (Naval Facilities Engineering Command)
- City of Fort Collins
- Washington State
- Building Owners/Property Managers as requested
What is cfm/ft^2 ?
One cubic foot per minute per square foot is the metric used to quantify air flow for a room or entire building.
What is IECC?
International Energy Conservation Code
Air Leakage Standard Practice according to IECC
2021 International energy conservation Code (IECC) requires building thermal envelope testing in accordance with ASTM E779, ANSI/RESNET/ICC 380, ASTM E3158, or ASTM E1827 such that the measured air leakage shall not exceed 0.40 cfm/ft^2 (at 75Pa pressure)
What qualifies as an air barrier material?
- self-adhering membranes
- some building wraps
- fluid-applied waterproofing/air barrier
- precast and cast in place concrete
- extruded polystyrene (XPS) or foil faced polyisocyanurate rigid insulation
- polyethylene film
- glass & metal (storefront/curtain wall/fenestrations=windows)
- fully adhered roof membranes (TPO, EPDM, Modified, Built-up, etc)
- fully adhered butyl or modified asphalt underlayment’s
What does air barrier testing identify?
ABT identifies the air leakage rate of the building at the specified test pressure. The air leakage rate is found as the difference in pressure (ΔP) across the barrier.
What do Building Air Leakage Diagnostics identify?
Building air leakage diagnostics identify the locations of the air barrier system discontinuities that allows for free air migration in and out of the building.
What is infiltration?
Infiltration is a natural phenomenon that occurs when the pressure on the exterior of a building
is higher than the interior causing outside air leaks through the building envelope from outside to inside.
What is mechanical pressurization/ventilation?
Mechanical pressurization/ventilation controls building pressure by means of fans, vents, and forced air. Major types of mechanical ventilation/pressurization are positive-pressure systems and negative-pressure systems. The two differ in whether the house interior is at a higher (positive-pressure) or lower (negative-pressure) static pressure than the outside static pressure.
What flow rates are considered leaky, average, and tight according to ASHRAE?
- Leaky: >0.4 cfm/f^2 (@75Pa)
- Average: 0.3-0.4 cfm/f^2 (@75Pa)
- Tight: <0.3 cfm/f^2 (@75Pa)
What is the ASHRAE?
The American Society of Heating, Refrigerating and Air Conditioning Engineers is an American professional association seeking to advance heating, ventilation, air conditioning and refrigeration systems design and construction.
