Moderate Rehabs in Pre-War Buildings: Practical Limits to Hydronic Building Energy Savings

Written by Bryan Simpson, Mechanical Engineer

New York City has established high goals for CO2 reductions as part of the 80 x 50 plan enacted under Mayor de Blasio’s administration. In short, NYC aims to reduce its CO2 production by at least 80% by 2050 (from a 2005 baseline). This requires vast energy conservation and renewable energy production proliferation across the city’s energy, transportation, waste management, and building sectors. Buildings themselves account for 68% of current CO2 production in the City, and as such have the largest reduction targets1. Goals can only be met by implementing repeatable and scalable scopes of work in coordination with policy updates and improvements in other energy sectors. To better understand the efficacy of these moderate improvements on overall energy consumption, we’ve analyzed the results from a recent portfolio rehabilitation. These findings help us to create a map of where we need to go in order to approach 80 X 50.

Figure 1: 80 x 50 NYC Buildings CO2 Reduction Goals, NYC Mayors Office of Sustainability, Roadmap to 80 x 50 Report

Read more

Laundry Rooms are Complicated: Integrating Vented Clothes Dryers in Multifamily Passive House Projects

Written by the SWA Passive House Team

Common laundry rooms are typically provided in market rate and affordable multifamily buildings. Because there are no ventless clothes dryers available for commercial use in North America (such as condensing or heat pump dryers), Passive House (PH) projects must make do with standard coin-operated, conventional vented clothes dryers. With a conventional electric or gas vented dryer, ambient air from the laundry room is heated and blown into the dryer’s drum as it tumbles. This air picks up the moisture from the laundry and is exhausted – sending hot moist air and lint particles to the outside. For any dryer that exhausts more than 200 cfm and in common laundries that have several dryers, make-up air must be supplied to the room so the dryers have enough air to operate properly. This make-up air must then be heated or cooled and therefore, increases the building’s energy demand.

Read more

Solar Photovoltaics and New York Energy Code

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

Why the Whole Building Approach Matters

At Steven Winter Associates, Inc., we support the whole building approach to design and construction by doing our best to ensure that projects meet sustainability, energy efficiency, and accessibility requirements, among other design strategies and goals. From our perspective, accessibility compliance is a key factor in determining whether a project is truly sustainable and efficient.

The Whole Building Approach to Design (from the Whole Building Design Guide, “Design Objectives”)

As an example, I was recently contacted by a New York City-based housing developer. They received a letter from an attorney stating that three of their recently constructed projects in New York City were “tested” and found to be noncompliant with the accessible design and construction requirements of the Fair Housing Amendments Act and the New York City Building Code. SWA toured the buildings and confirmed that the allegations were in fact true. We identified issues such as excessive cross slopes along the concrete entrance walk, the presence of steps between dwelling units and their associated terraces, the lack of properly sized kitchens and bathrooms, the lack of compliant clear width provided by all user passage doors, etc. It quickly became apparent to us and to the developer that the cost of the remediation required to bring the projects into full compliance would be astronomical.

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