Building Envelope Testing (Blower Door Testing)
United has the benefit of being based in an area with fast moving building requirements. Washington started to implement Air Barrier Testing in 2013, and have increased the stringency of the testing every few years since then. As of July 1, 2020, Washington has begun requiring testing in compliance with ASTM E 779. Our familiarity with this testing, and the fact that we have been performing it for more than 5 years give us the confidence and experience to be able to complete any testing you can imagine. United has invested tens of thousands of dollars in our equipment as well. We have 15 Blowers, 4 Infrared Cameras, and hundreds of feet wiring and cabling. We are one of the few companies that can mobilize the required fans immediately.
What is Involved in the Testing?
Our testing is done in accordance with the specification, and the applicable standard ASTM E779. This test should be scheduled near the end of the project right before the project turns over. United request a scheduling notice 2 weeks before the scheduled date to allow for shipping our equipment and booking travel to the site if it is remote. After reviewing the architectural plans provided, we will determine the total air barrier (floor ceiling walls). Based upon the square footage, and leakage requirements, we will determine the number of fans, gauges, and the necessary door frames, cords and hoses to properly pressurize and depressurize the building. Our fans require 15 amp breakers per fan when running at capacity.
The following procedures may be modified during testing depending on site specific requirements, but any deviations will be listed in the final report:
- United will start by recording the conditions of the inside and outside of the building.
- Fans will be setup, cords will be run, and hoses positioned to the ideal locations.
- United will walk the site with the contractor to verify that all of the above preparations have been made.
- A preliminary test will be performed to determine if everything is ready, if there are obvious issues, we will start back at step 3.
- Once the preliminary test indicates a reasonable amount of leakage, and pressure, then we will start our pressurization test.
- The fans will be ramped to maintain a minimum of 50pa of pressure in the building, leakage measurements will be recorded, and then the fan will lower 5pa. Pressure measurements will be taken at every 5pa interval until a total of 10 pressure points are tested.
- If the test fails we will re-pressurize and begin the diagnostic testing, if not we will begin our depressurization test (if required).
- Steps 3 through 7 will be repeated for the Architectural Plus HVAC testing (if required)
If the test fail to meet the maximum allowed leakage rates, then United will begin the diagnostic testing portion of our scope. This testing will seek to indicate where the leakage is occurring using Find, Feel, Infrared or Fog. These test occur on a pressurized building to emphasize the leakage.
Find: Visually inspecting and recording with a digital camera areas that appear to have obvious gaps in the air barrier. These typically include poorly installed roll-up doors, or slabs that do not meet the exterior wall.
Feel: The process of walking through the structure looking for drafts, and obvious air movement. This will typically indicate issues where a flashing or sealant is missing around roof/wall penetrations.
Infrared: Using our infrared cameras we will attempt to capture temperature gradients that indicate where air is freely flowing between different air barrier components.
Fog: Using our specialized fog generators we can further diagnose items that we discovered during our Find and Feel inspections.