Party Walls

A few months ago I wrote about air-source heat pumps (ASHPs) in cold climates, and I promised more info on how to select the right systems and get the best performance. Below are some things we’ve learned from our work with ASHPs in the Northeast; much of this is based on the results from a study supported by the DOE Building America program. To be clear, we’re talking about inverter-driven (variable-speed) heat pumps in residential applications during heating season. Cooling is certainly important also, but we’ve been more focused on the heating performance, especially at lower temperatures. (more…)

In the first two entries of this series (Part One | Part Two), we explored advanced controls for electrically heated buildings; combined heat and power systems; upgraded atmospheric boilers and ventilation systems. For the final installment of SWA’s Favorite Multifamily Retrofits, we’ll examine the ins-and-outs of stand-alone energy storage. (more…)

Earlier this year, at the AHR Expo in Orlando, the biggest trade show for HVAC professionals, Aeroseal’s duct sealing technology was declared the Product of the Year, the top honor of the Innovation Awards. Aeroseal was recognized as “a groundbreaking solution to an industry-wide problem.”

The unique appeal of the Aeroseal technology is that it seals ducts from the inside. Walls and ceilings do not need to be removed or damaged to gain access for traditional mastic sealing. Aerosolized vinyl polymer particles from 2 to 20 micrometers are injected into a pressurized duct system. The particles stay suspended in the air stream until they reach the leaks, where they are deposited and built up at the leak edges until the leaks are sealed.

The Aeroseal technology has been around for more than two decades. It was developed at Lawrence Berkeley National Laboratory in the early nineties and patented in 1997. It has received many awards over the years including the Best of What’s New award from Popular Science magazine in 1996 and the Energy 100 award from the U.S. Department of Energy.

So what’s the big deal?

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In our first entry of this three-part series, we described advanced controls for electrically heated buildings, combined heat and power systems, and upgraded atmospheric boilers. This time around, we’ll examine the ins-and-outs of exhaust ventilation in multifamily buildings. (more…)

I’ll save the long-winded introduction and get straight to the facts. Based on New York City’s publicly available Local Law 84 (LL84) benchmarking data for 2015, hotels emit 32% more greenhouse gas (GHG) per square foot than the average for all buildings. I also want to qualify this by making a few statements about the data:

1. There are 13,973 buildings on the Department of Finance list; of which 2,353 did not comply with LL84 or are not required to comply.
2. We removed the outliers. Weather-normalized source energy use intensity (EUI) over 550 and under 100 (kBtu/ft2) typically indicates erroneous data. Most likely either the building’s benchmarking activities or report filed with NYC were completed incorrectly.
3. A significant portion of the list comprises the buildings with erroneous data: 4950. Seems a little crazy, no? Leaving us with a good topic for another day….
4. For clarity, that means we analyzed the remaining 6,654 buildings.

The good news – for the sake of this post – is that the hotel market had one of the higher rates of correctly reported compliance data. Out of 187 buildings, 143 reported with numbers that were in a normal range. The average for the sector however, reflects EUI and GHG emissions per square foot that are much higher than other similar building types. Multifamily buildings, for example, have an average of 42% lower GHG emissions/ft2 than hotels (see table below). (more…)

There is no single retrofit that is a panacea for all multifamily buildings. There are myriad options and permutations for upgrades, the efficacy of which is defined by the operational needs, budget, and goals set by the owner. With that in mind, we will examine six retrofits popular with SWA clients in this three-part blog series. (more…)

Air-source heat pumps are a booming business. In the Northeast, manufacturers report that sales of residential systems have increased by 25-35% per year over the past 5-10 years. We’ve seen more and more systems being installed in existing homes (to provide cooling while offsetting oil or propane used for heating) and into new homes (often as the sole source of heating and cooling).

We’ve looked into these systems often, and from many perspectives. I’m planning a series of posts, but, for now, here are the answers to some basic questions we receive from clients.

First, the basics: What is an air-source heat pump (ASHP)?

It’s an air conditioner that can operate in reverse. During the summer, it moves heat from indoors to outdoors. In the winter, it moves heat from outdoors to indoors. We helped NEEP (the Northeast Energy Efficiency Partnerships) to put together a market assessment and strategy report on ASHPs. The early sections in this document (see p. 12) outline the different terms and types of heat pumps (ducted/ductless, split/packaged, mini-split, multi-split, central, etc.) Unfortunately, different people can use the same term to mean different things, but hopefully the NEEP Northeast/Mid-Atlantic Air-Source Heat Pump Strategies Report can help clarify things.

 

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Do you live in DC? Do you own, manage or reside in a multifamily building? If so, we would love to get your feedback!

The District of Columbia’s Department of Energy and Environment (DOEE) has engaged Steven Winter Associates to gain feedback from multifamily owners, managers and residents about their energy and water usage. To start off, we’re conducting brief surveys (10-minutes max), and hope this effort will have positive outcomes for future multifamily projects in DC by raising awareness of green/energy efficiency initiatives.

PURPOSE:
Survey responses will inform the potential development of a voluntary energy and water conservation program tailored exclusively for the multifamily rental sector in the District. This program will include a customized toolkit to engage residents and building managers in improving energy and water efficiency. It will also encourage participation in a peer-to-peer energy and water reduction competition.

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Last week, I had the opportunity to visit the DURAhome, New York City College of Technology’s entry for the 2015 Solar Decathlon. This project is currently nearing completion at the Brooklyn Navy Yard. Over the past 3 months, more than sixty students have toiled around the clock to finish construction in time for the contest, which will take place October 8-18 in Irvine, California. The Solar Decathlon is the U.S. Department of Energy’s biennial competition that challenges college and university student-led teams to design and build solar-powered net-zero homes that are affordable, energy-efficient, and aesthetically appealing.

TeamDURA’s focus was to create a prototype of post-disaster housing that is suited for New York City’s high-density urban environment, and could serve as a shelter in the aftermath of a catastrophic storm. As such, multifamily, multistory solutions were preferable to traditional single-family trailers, which have larger footprints. DURAhome consists of several prefabricated modules that can be packaged and shipped on standard-sized tractor trailers for quick response at low cost. These flexible modules can then be joined in standalone configurations or stacked for multifamily uses. Like the city, the DURAhome is diverse, urban, resilient, and adaptable.

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I love to cook. And like most cooks, I love to cook on my gas range. But I am also a building science researcher, and the researcher in me doesn’t understand how we allow gas ranges in homes. Building codes and energy efficiency programs have pushed the housing market towards all combustion appliances being sealed combustion and direct vent. Our furnaces, boilers, water heaters, and fireplaces are all going towards sealed combustion. Soon it is likely that building codes won’t even give you the option of using open combustion devices. This push for sealed combustion is an effort to drastically reduce the health hazards of carbon monoxide poisoning and other contaminants in our homes. As a researcher, this makes complete sense to me…but I, like many others, say “Don’t touch my gas range.”

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