With the increasing demand for green building practices, high performance building envelopes and required building testing by the Washington State Energy Code, it’s no wonder this type of performance testing has become popular over the last three to five years. There’s no slowing down in sight either, at least in the Pacific Northwest.
Many clients who have never been through testing before always ask the same question: What is the purpose of a whole building air barrier test? The obvious answer is that it’s required by Washington’s Energy Code; but also, because new buildings are under pressure to become more and more energy efficient. Testing the building for air leaks aids in determining how well it will perform as related to energy efficiency and leakage of conditioned air. At the end of the day, it’s a quality control program to make sure everyone throughout the construction process has built a quality, efficient building.
Importance of Equipment and Experience
First and foremost, your testing agency should be using calibrated equipment. Omission of a calibrated system can provide a false pass, or a false failure and neither of those results are warranted. Any test performed should be as accurate as possible, beginning with the appropriate calibration.
This segues into the next topic of technician training and/or certification. Any Joe Schmo can buy a few fans online and hit the big green button. Remember, this test is required in Washington to obtain your certificate of occupancy, and oftentimes is used for energy credits or LEED points. At the end of the day the accuracy of the test is everything, in which the testing technician certainly plays a big part. Common technician training includes, but is not limited to, certification through the equipment manufacturer, licensed mechanical engineer or another entity like ABAA or Passive House. The real intent with training is a formal process through a reputable organization and the competency of the testing technician plays a critical role in this process.
For commercially permitted building testing, there are multiple systems in a building that are excluded from the test. The major systems are: HVAC, plumbing and electrical. The biggest emphasis here is HVAC systems. For instance, in a residential-use building such as a mid-rise apartment building, there is a large quantity of individual HVAC features. Some of these things may include bathroom exhaust fans, dryer vents, range hood vents, AC ports, not to mention supply and exhaust for common areas. All of these ducts and vents need to be covered for the test to prevent airflow in or out of the building.
For commercial-use buildings such as offices, hotels, schools, etc., the HVAC units tend to be larger and roof-mounted. The same isolation requirements are necessary, but a different type of technique is used to get the job done. A benefit of the testing agency prepping the building (as opposed to contractor preparation) is a significant labor and supplies savings, as well as a reduction in liability for the contractor.
In addition to excluding HVAC, plumbing and electrical systems, there are additional building preparations needed. Every interior door must be propped open. Every exterior door and window must be closed and locked. Any temporary condition (commonly omitted weather stripping, door thresholds and other incomplete conditions) must be simulated for the test. For the best results, incomplete systems should be as minimal as possible.
Test Equipment and Industry Standards
The installation of testing equipment is a fragile balance of strategy and organization. On any given test we have hundreds of feet (sometimes thousands) of power cords, pressure measurement tubes, computer cords and so many other critical equipment placements. With many tasks to coordinate, just one pressure tube in the wrong place can skew the test. So, once again, the competency and training of the testing technician is critical for an accurate test.
Over the years, the testing industry has become more efficient and therefore more affordable. Some mindsets are that whole building air barrier testing is a very expensive process. You might be surprised to find how affordable it is, especially for simple structures such as single family homes, townhomes, etc. Commercial buildings and mid-rises/high-rises are obviously more complex tests and the fee structure is relative, but the days of $50,000 tests are long gone.
We understand this testing may be new to developers and contractors, and that’s okay. Most testing companies are willing to educate and work with you to achieve a comprehensive understanding. Should there be any part of the process that you need additional information, please contact your local testing agency.
Mike Poirier is vice president of QED Lab, Inc.