In the part one of this three-part series, we examined the efforts of contractors, manufacturers and the state of New York on a pair of apartment buildings in Saugerties, NY. The structures were given an upgrade by way of prefabricated panels designed to provide the best insulation, superior airflow control and energy savings. The New York State Energy Research and Development Authority measured the impact of the panels – part one indicated how the prefab panels were able to reduce the cost of heating and cooling. In part two, we will consider the improvements to the building envelope.
"The Burt Street apartments are ideal structures for this retrofit."
Tests show exterior panels promote air tightness
Panelized EIFS systems like the ones used on the Burt Street apartments have been proven to be effective at restricting unwanted airflow in and out of a structure. Blower door tests are one way to determine this ability. The test involves placing a fan over the front door, closing all windows and doors, having the fan suck air out of the building and measuring how much air is pulled through fissures and cracks in the exterior.
The NYSERDA performed baseline tests on the apartments before construction. The follow-up blower door test after the panels are fully installed should indicate a significant improvement in building envelope. That effect will result in lower energy use and reduced utility costs. The construction team noted how the Burt Street apartments are ideal structures for this retrofit:
"The small multifamily building has a simple building geometry and repeated facade patterns that are highly suitable to off-site panelization of exterior wall insulation system," the team explained. "The building is master-metered for electricity, with the building owner paying for all utility costs. [The building owner is] committed to energy efficiency as demonstrated by the previous retrofit."
Building envelope plays a major part in performance
While the insulation provided by the exterior wall assembly systems is not to be overlooked, it isn't the only aspect of these panels that can produce energy savings. The building envelope is what keeps moisture, drafts and unwanted debris and spores from infiltrating a structure. Not only do these elements disrupt air quality and comfort, they also tax the heating and cooling systems and reduce building performance.
In many buildings, the envelope is one of the first things to go. That's because original construction teams may not have placed necessary emphasis on providing lasting, effective exterior coatings to seal off any potential cracks and openings. However, there are now building materials like the retrofitted panels used in this project that act as an above-average air and moisture barrier. No builder can rightfully believe he or she has constructed a high-performance space without giving ample thought to the envelope.
Once the NYSERDA conducts the post-construction blower door tests, they can provide quantifiable data on the effect of the panels. But it is still safe to say they will have a noticeable influence on the Burt Street apartments' ability to deter air and moisture.