As the number of projects pursuing Passive House certification increases, so does the demand for whole building blower door tests. And so, performance of recent blower door tests took us to uncharted territory, not only for SWA, but for the Passive House Standard.
Working remotely with a project team across the globe, the Passive House team at SWA was tasked with retrofitting an outdated factory in Katunayake, Sri Lanka, into a Passive House certified garment manufacturing facility. Jordan Parnass Digital Architecture (JPDA) recruited SWA to provide technical assistance to the project team. Responsibilities for this project included Passive House design analysis and recommendations, mechanical design review, energy and thermal bridging modeling, and the testing and verification necessary to achieve certification from the Passive House Institute (PHI).
This project was unique for many reasons. First and foremost, when completed, the Star Garments facility will be the first Passive House certified building in Sri Lanka. Second, the project will be certified to PHI’s stringent EnerPHit standard, a Passive House certification that was designed for the renovation of existing buildings. Lastly, the project’s location in a hot and humid climate, combined with its use as a manufacturing facility, resulted in various complexities that the project team had to overcome. To learn more about the design process, check out the Star Garment Case Study.
Planning the Site Visits
SWA’s first visit to the site was roughly halfway through construction. Tests were performed at various mockup wall and window locations for air tightness. The second visit was for the final whole building blower door test. As the final trip approached, many logistical considerations needed to be determined.
- Do we use our own equipment or try to rent equipment that is closer to the project site?
- The closest rental locations we could find were either Germany, UK, or Australia. With the cost of shipping and rental fees, not to mention the uncertainty of items being received in time, we decided to use our own equipment.
- If we use our own equipment, how can we get it to work on the local power supply?
- We reached out to The Energy Conservatory and they were very helpful in sorting this out. As we learned, the blower door speed controller has a chip for 60 Hz installed, which can be swapped for a 50 Hz chip. The swapped chips, in conjunction with 240v to 120v step down voltage transformers, enabled us to use the equipment overseas without any hitches.
- How do we get all the equipment there and back?
- Bring it as checked baggage on our flight? Ship via air freight? Is there a slow-boat option? We investigated all the possibilities and found the greatest balance of convenience, cost, and timing was through DHL Global Forwarding, the air freight option. We added in extra buffer time to ensure the equipment would be there by the time we arrived.
- What if some specialized piece of equipment doesn’t work when we are there?
- A few extra days were built in to the trip, so if we needed something we could hopefully have it sent via expedited air. Luckily, we didn’t run into any problems with equipment.
Equipment loaded in Sri Lanka en route back to the USA.
After an initial flight delay of 6.5 hours, leaving on a Tuesday, and connecting in Dubai, SWA’s Dylan Martello and Mike O’Donnell arrived in Sri Lanka on Thursday morning 4/26/18. Most of the trip was spent working towards the blower door test, although there was a little bit of time for sightseeing. On Friday, Dylan and Mike went to the site to check on all the equipment. On Saturday, they began to prepare the building by taping off ventilation ductwork and such. On Sunday, the initial testing was to be performed, but unfortunately total building air leakage was exceeding the allowed 1.0 ACH50 acceptable for EnerPHit projects.
Luckily, Dylan and Mike were able to identify several areas of air leakage, most notably where the steel purlins connected to the roof. In the long run, it was actually better to find one large repeatable leak, rather than lots of pinhole leaks, so that remediation work could take place more easily. There were 19 of these locations.
Before and after condition of steel purlin connections.
Since it was a local holiday, getting materials to correct the leakage areas was a bit of a challenge, and scrap foam pieces were ultimately used to block the openings along with the little bit of canned spray foam available on hand to seal the areas on the interior. This interior air sealing was done in conjunction with exterior caulking to ensure these locations were completely air sealed. Because EnerPHit requires that before and after airflow measurements are taken of leakage areas to show the improvement, SWA documented the air leakage reductions at these conditions. On average, air leakage was reduced anywhere from 85-99% at these locations!
It was an all hands-on-deck effort with collaboration between the architect, contractors, and building owner/operator to pull this off. It is undoubtedly an experience to be remembered for years to come.
The project has submitted paperwork to the Passive House Institute and is currently awaiting final certification. Stay tuned for a follow up blog on building performance and energy reduction data at the Star Garments facility.
By Michael O’Donnell, Senior Energy Consultant