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Tag: Energy Efficiency

It’s Beginning to Look a Lot Like …. Cold Season

Imagine it’s Christmas morning. You wake up from a nice sleep eager to spend time with family and open presents. You can’t wait to get out of bed but know that the warmth you have under the covers will soon escape into your cold, drafty apartment. The window doesn’t close that well, and the baseboard heater can never quite get up to the desired temperature. Now you’re cold. Your body is working harder to warm you, so now you’re tired too. Your only comfort is the idea of sitting by a fire soon with a cup of hot cocoa… except it’s not actually Christmas. It’s just a normal day, and you’re cold…again.

For most of us, feeling cold is simply just uncomfortable and may decrease our productivity. However, for the elderly being cold can lead to health problems, organ failure, and even hypothermia. Seniors who are chronically cold during the winter may not even know the toll their discomfort is causing to their health, and they may require a more adequate living environment to keep them safe.

When preparing for the development of a new senior residence, it is important to take into consideration the needs of the senior demographic during the design phase. Keeping our seniors safe is one of the biggest priorities for senior living facilities, not only when it comes to ADA compliant and accessible living conditions, but also regarding tenant comfort and health.

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Why Commission Solar Photovoltaic (PV) Systems?

Falling costs and rising demand for clean energy have increased the specification and installation of solar photovoltaic (PV) systems worldwide. In NYC, Local Laws 92 and 94 require solar PV and/or green roofs on all new buildings and alterations where the existing roof deck is being replaced. Third-party commissioning increases the likelihood that a PV system will perform as designed throughout its lifetime and reduces poorly performing PV systems, which erode the bottom line and damage solar energy’s reputation. This is probably why the NYC Energy Conservation Code requires that renewable energy systems greater than 25 kW be commissioned (C408.2).

Many factors can affect a PV system’s power output. Let’s look at some reasons why output may be less than expected.

Design Flaws

Commissioning agents help prevent design flaws when brought onto the project early in the process. Here are a few common design flaws:

Electrical Issues: In traditional string systems, modules are wired in series to increase voltage, as shown. However, if too few or too many modules are wired in series, the voltage will be outside of an inverter’s input range and there will simply be no power output. If modules of dissimilar current are wired together output will be reduced since the current of a string is limited by the module with the lowest current.

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NYC Building Energy Letter Grades: What Property Managers Need to Know

Building energy efficiency labels are now available for property owners of large NYC buildings to download and post in their lobbies. Each year, the labels will be available on October 1st and must be posted by October 31st. Failure to display the label for applicable buildings by the October 31st deadline will result in a violation from the Department of Buildings and fine of $1,250.

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Electrifying Central Ventilation Systems in Multifamily Buildings

A common strategy to provide ventilation in multifamily buildings is to design a central roof-top air handler that distributes outdoor air to each unit. The energy cost for this system, which commonly uses natural gas for heating for either a gas furnace unit or hot water from a central boiler is paid for by the building owner. However, there is another option – VRF[1]. With the unprecedented rise of VRF technology in the last decade combined with regulations such as New York City’s Local Law 97 of 2019[2] (carbon emission penalty), the industry is taking a giant leap towards building electrification. There are always questions and concerns raised against building electrification ranging from initial cost to operating cost to reliability of the VRF technology. From the owner’s perspective, the biggest question is usually surrounding the operating cost of an electric system compared to a natural gas system for heating, but the cost of ownership must consider multiple energy metrics. I was curious to understand the impact on various building energy profile metrics associated with a Dedicated Outdoor Air System (DOAS) using the conventional gas fuel source vs. the latest VRF heat pump technology using electricity in a multifamily building. The findings of this investigation challenge the deep-rooted notion that electricity, being more expensive than natural gas per BTU, will always cost more to operate.

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Pirelli Historic Retrofit: Part 1

 

image of Pirelli buildingOne of the most important drivers in achieving Passive House certification (or achieving any goal!) is getting the project team involved from the start. Becker + Becker, the owner, architect and developer for the creative retrofit of the Pirelli Building, hired SWA’s Passive House, LEED, Enclosures, and Accessibility teams to coordinate during early design. Becker +Becker is invested in rebuilding for resilience, sustainability, and occupant health and comfort and appreciates the necessity of getting goals defined at the outset.

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AeroBarrier: A New Tool for Gut Rehabs?

Image of AeroBarrier eventAeroBarrier is touted as the best route to never fail another blower door test. The technology, which involves pressurizing a space with a blower door fan while misting a water-based glue into the air from multiple points throughout the space, is most often being used on new multifamily buildings after drywall is installed. SWA first experimented with the technique on the Cornell Tech high-rise building. Back in March, I reached out to Yudah Schwartz at SuperSeal Insulation, Inc. about a personal project, the gut rehab of a 2,500 SF detached single family home. While renovations aren’t something they normally do, Yudah and his team agreed to try a demo. Here’s what happened.

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The Numbers Are In! NYC Passive House Performance Data

In a collaborative effort that merged financing and energy use analysis, the New York City Passive House industry finally has performance data. Working together with Bright Power, The Community Preservation Corporation, and NYC Department of Housing Preservation & Development, this analysis is the first of its kind.

Why does this matter?

Energy Use Intensity (EUI) measures energy consumption on a per square foot basis to compare buildings and allows interested parties to gauge one building’s usage to another (or to a group of buildings with a similar use type). The study team compared the actual EUI of six completed Passive House-certified and Passive House-like buildings against recently completed multifamily code-built buildings. Information was gleaned from the EnergyScoreCards database and the Passive House (PH) target. The weather normalized data indicates the Passive House and Passive House-like buildings are performing much better than the comparable code-built group, but are not quite as efficient as the Passive House threshold. Industry leaders have recognized this performance gap – between predictive assumptions that rely on standardized patterns of use and the real-life habits of actual people living in the building. This gap has been a hot topic  at the past several New York Passive House conferences. The results from the current analysis provide a starting point now, so the industry can focus on strategies to continue to reduce EUIs.

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How to Talk Windows with a Passive House Nerd

Before we get into this topic, please take a few seconds to consider the following questions:

  • Do you plan to work, or have you ever worked, on a Passive House building? (If not, the rest of your answers are probably no.)
  • Has your Passive House consultant ever told you that the window U-Value you provided “won’t work in their energy model?”
  • Has your Passive House consultant ever told you that your window “doesn’t meet the comfort criteria?”
  • Have you ever scratched your head when someone asked you to provide the “Psi-spacer” for your window?

If you answered yes to two or more of these queries, please read on. If not, you’ll still learn some useful information, so why not continue?

If you’re still reading, then you are probably somewhat familiar with a “U-Value” and you may know what “SHGC” means. If not, no worries. This article will explain both, and by the end you’ll be able to talk about these terms with most Passive House nerds.

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Net Zero and Electrification

Net zero” can mean a lot of different things depending on what you choose to measure – zero energy usage, zero carbon emitted, zero lifecycle impact, etc.

At Steven Winter Associates, Inc. (SWA), we work with clients who are approaching net zero from different angles: driven by institutional goals, climate concerns, marketing campaigns, and connecting with municipal emissions targets. One thing we see over and over is that super high performance is difficult to achieve, but with a key simplification – there are not many ways to do it. All roads may lead to Rome but the closer you get, the fewer roads there are to take.

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Choosing Insulation for Carbon Value – Why More is Not Always Better Part 2

In Part 1 of this blog post, we highlighted two of the most commonly used insulations in the U.S.– XPS board and closed-cell polyurethane spray foam – and noted that they are produced with blowing agents (HFC-based) that are putting more carbon into the air during construction than they save during building operation for many decades. We left you with a question: if we don’t use these insulations, how can we make up for the loss of the helpful qualities that has made us dependent on them?

Insulation Alternatives

One part of the answer comes from the development of new materials. In Europe over the last decade, Honeywell developed a new blowing agent, a hydro-fluoro olefin (HFO), which claims a global warming potential (GWP) of less than one, which is less than that of carbon dioxide.  First in Europe, and now in the U.S., manufacturers such as Demilec and Carlisle are coming to market with a closed-cell polyurethane spray foam that uses this blowing agent instead of the HFCs that carry a GWP of well over 1,000. These spray foams have a slightly better R-value  than their high-carbon predecessors, and otherwise have the same qualities that make them useful in multiple contexts – air/vapor barrier capability, conformance to irregularities and penetrations, etc.  However, they also have many of the same downsides – high flammability, potential (and not completely understood) off-gassing post-application, and the basic fact that they are petroleum products.

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