Recovering from Heat Recovery Woes

IECC Image

The International Energy Conservation Code (IECC) has a number of requirements involving energy recovery on ventilation systems. Requirements vary based on climate zone, building type and size, equipment capacity, and equipment operating hours. As a result, many new construction projects must now incorporate energy recovery considerations into their design.

An energy recovery unit (ERU) equipped with a heat wheel can be a great way to satisfy these energy recovery requirements. The ERU can be a roof-mounted air handling unit, or can be an air handling unit located inside a mechanical room with outdoor air and exhaust streams ducted in. The heat wheel is positioned so that half of the wheel sits in the exhaust air duct and the other half sits in the outdoor air intake duct. During cold weather, the wheel spins, transferring heat from the exhaust stream to the outdoor air intake stream. During hot weather, the wheel transfers heat from the outdoor air intake stream to the exhaust stream. In both cases the heat exchange enables the building to take advantage of the more comfortable conditions of the exhaust air, while still allowing fresh air to enter the building. During extreme weather conditions, heat wheels can save energy on space conditioning while still allowing for healthy indoor air quality.

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When the Rubber Meets the Road

 

As the Passive House standard continues to make waves across New York City and the U.S., an entirely new design process has evolved to respond to the challenges of higher insulation levels, balanced mechanical ventilation, and perhaps the most difficult hurdle – an air tightness level that most would think is impossible. For the recently certified Cornell Tech building on Roosevelt Island, the tallest Passive House in the world, a several year-long coordinated effort was required to achieve such a feat. So what is the requirement, how is it measured, and what are the strategies and considerations required to achieve it?

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It’s all in the Details: Designing for Passive House & Accessibility Compliance

The number of multifamily residential projects targeting Passive House certification has been rising steadily over the past several years, bringing along many exciting challenges. This has been especially prevalent in New York City, where increasingly stringent energy standards and a desire for innovation have made designing to Passive House standards an attractive goal. As the number of these projects passing through our office continues to grow, we have discovered some important overlaps with one of our other consulting services – Accessibility Compliance.

In the United States, multifamily new construction projects consisting of four or more dwelling units are subject to the Fair Housing Act, as well as state, city, and local accessibility laws and codes. For the purposes of this blog we will focus on projects in NYC, although the majority of newly constructed residential projects across the country will be subject to some variation of the criteria discussed below, for both Passive House and Accessibility standards. With this in mind, we have chosen a couple of common problem areas that require particularly close attention. Read more

Tech Notes: Accessibility of Luxury Amenities

Bathtubs for Pets® Model ADA60HGTY

As the development of luxury multifamily housing in primarily urban areas continues to rise, SWA’s team of accessibility consultants has been encountering more and more specialty rooms and features that bring accessibility into question. Wine cellars, yoga and meditation rooms, and even clothing vaults (fur coat, anyone?) are all making their way onto the scene as luxury amenities available for residents of high-end real estate. While current accessibility laws and codes remain silent on many of these types of spaces specifically, they are not exempt from accessibility requirements.

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Transformers: Problems in Disguise

Sometimes a significant source of energy inefficiency in a building can be hiding in a place difficult to detect. In some buildings, a single transformer can have a substantial impact on electrical consumption.

Image of currents flowing through a transformer

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Some Background

Transformers are responsible for stepping the incoming voltage to a building up or down depending on the design, intended use, or connected equipment.  A standard electrical socket in a US home or office will deliver 110-120 volts AC. Some appliances require 240 V instead. Large mechanical equipment, such as the air handling units, distribution pumps and chillers found in commercial or multifamily buildings may require 460 V. In buildings where the incoming voltage from the utility does not match the voltage required by connected equipment, a transformer is used to deliver the necessary voltage.  The voltage entering the transformer is called the primary voltage and the voltage delivered by the transformer to the facility’s equipment is called the secondary voltage.

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