#UnfreezePA: SWA at the Helm of the PA Icehouse Demonstration

On Tuesday, June 6, 2017, leaders of Pennsylvania’s clean energy movement took to the steps of the State Capitol Building. The cause? To demonstrate just how much room PA State Energy Codes have to improve. Amidst a cohort of speakers and presenters, USGBC’s Central Pennsylvania chapter erected two sheds, each filled with 1,080 pounds of ice: one built to 2009 Code requirements, currently in place under PA state law; and the other built to Passive House standards. Over the course of the month of June, the public will be able to watch as the respective blocks of ice melt within their structures. Ultimately, the difference in the rate of ice melt between the Code House and the Performance House (Passive House) will illustrate the degree to which current energy laws and codes are lacking, while simultaneously offering a model for advancement.

Code Icehouse 3pm 6/14

Performance Icehouse 6/14

In 2009, the International Energy Code Council (IECC) developed energy-saving standards that were adopted by most U.S. state governments. While the 2009 Code was widely instituted in the period following its publication, several states have since embraced even more efficient requirements that are quickly replacing outdated terms. For instance, the state of Maryland – comparable to Pennsylvania in terms of climate, population, and demographic spectrum – is operating under requirements equivalent to 2015 IECC standards.  New York, New Jersey, Massachusetts and Vermont are other states in the same geographic region and general climate zone that have opted towards more energy efficient codes.[1]

Passive House, on the other hand, is a set of design principles that aim to attain a “quantifiable and rigorous level of energy efficiency within a specific quantifiable comfort level.[2]” More simply, Passive House projects go above and beyond the statutes of any enforced codes to follow a “maximize your gains, minimize your losses” approach to building design. The Passive House Institute of the United States (PHIUS) provides the following summary of Passive House principles: Read more

Arc – A Performance Approach

“What gets measured, gets managed” – Peter Drucker. This old management adage couldn’t ring more true in the world of sustainability.

The green building industry increasingly relies on the collection and analysis of data to inform a spectrum of building improvements, including monitoring and mitigating the impact of operations and management. The GBCI has embraced this new direction by developing and releasing a new online platform, called Arc, which collects, manages, and benchmarks building performance data as projects move toward LEED certification.

Screen shot of the Arc Platform

Screen shot of the Arc Platform

Read more

Solar Photovoltaics and New York Energy Code

By Eric Wallace, Energy Engineer

Industry Trends

Over the past decade, the story of solar photovoltaic (PV) power has been one of both accelerating deployment and consistent, significant reductions in cost. This success has been driven by increasingly advantageous economies of scale, and supported by incentives and initiatives at all levels of government.

Figure 1. Solar PV systems have seen a dramatic reduction in cost

In late 2015, the federal Investment Tax Credit [3], a primary financial incentive for solar PV systems, was extended at its current rate of 30% through 2019, despite a contentious environment in Washington. It is scheduled to be stepped down through 2022, after which the commercial credit will expire and the residential credit [7] will remain at 10% indefinitely.

The National Renewable Energy Laboratory’s annual solar benchmarking report [4] shows that over the past seven years, PV system costs have dropped 58.5% in the residential sector, 59.3% in the commercial sector, and 68.2% in the utility-scale sector. As a clear sign of the times, utility-scale solar achieved the U.S. Department of Energy (DOE) SunShot Initiative’s goal of $1.00/W early this year, three years ahead of schedule [9]. According to the U.S. Energy Information Agency (EIA) [8], these trends should continue, leading to solar power’s increasing presence as a key component of the national electrical generation mix. The EIA projects solar to be the fastest growing form of renewable energy, increasing by 44% by the end of 2018 for a total deployed capacity of 31 GW and accounting for 1.4% of utility-scale electricity generation.

Read more

Five Year Solar Performance on Connecticut Home

Written by Gayathri Vijayakumar, VP – Senior Building Systems Engineer

Over the last 10 years, we’ve seen great strides in the solar PV market in the United States. Between the federal tax credit and utility-sponsored incentives, the price to install PV systems came within reach of many homeowners. For others, eager to make a positive impact on the environment, power purchase agreements with solar companies and no up-front costs made it possible to utilize their roofs to generate electricity.

While the calculated cost-effectiveness of solar panels relies on the future price of electricity (which we can’t predict), we can confirm that they do deliver energy. In a very scientific study of exactly one home, owned by a SWA engineer, five years of generation data is available. Sure, it’s not the pretty Tesla roof, but these panels were installed back in November 2011. At 4.14 kW, with no shading and great Southern exposure, the panels were estimated to generate 5,400 kWh/year of electricity in New Haven, Connecticut (Climate Zone 5). The panels have exceeded expectations, generating on average, 6,200 kWh/year, which is roughly 70-80% of the electricity required by the 2,500 ft2 gas-heated home and its 4 occupants.

Read more

High Performance Walls

Written by Joanna Grab, Senior Sustainability Consultant

Groggy and sleepy-eyed, I swung my feet out of bed this morning. Still waking up, I began the trek to my coffee pot, but was thrown off track when my bare feet stumbled (literally) upon a freezing patch of floor beside the door to my balcony. Suddenly wide-eyed, I ducked into the bathroom to rub my toes against my fuzzy bath mat. Outside, the city seemed to have surrendered itself to a single shade of gray, and though my feet were warming, I could feel the monochromatic January cold pressing its way through the metal window. I put on my architect’s (hard) hat and thought, “these are textbook examples of thermal bridging.” But aside from a chill or a draft here and there what’s the big deal? Well, let me provide a little insight.

Thermal bridging occurs when heat is lost through a less-insulated or more-conductive portion of a building’s exterior. On a frigid winter day, this means heat is lost where insulation is lacking, such as through a metal window frame or the floor slab in my apartment building. Ultimately, thermal bridging results in a less comfortable home that is more expensive to heat and cool.

Another hidden concern is condensation, which can be a consequence of thermal bridging. When warm air comes into contact with a cold spot on the floor or wall, water vapor in the air cools and collects as droplets on the colder surface. This can result in durability problems, as well as poor indoor air quality.

Read more