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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

click to enlarge

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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Designing Solar for High Density Areas

As seen in:

Humans have been trying to harness the power of the sun for millennia. The advent and popularization of photovoltaics in the latter half of the twentieth century made doing so accessible to the masses. Today, solar arrays are commonly seen adorning the roofs of suburban homes and “big-box” retailers, as well as on other landscapes including expansive solar farms and capped landfills. Until recently, the common thread amongst these locations has been the employment of open space. Solar applications have historically been reserved for use in areas of low-to-moderate building density.

By the end of 2050, solar energy is projected to be the world’s largest source of electricity. While utility-scale solar will comprise the majority of this capacity, there will also be significant growth in the commercial and residential sectors – particularly in cities. Industry influencers are increasingly focused on creating opportunities for solar applications in high-density areas, where much of the demand lies.

In their 2014 Technological Roadmaps for solar PV and solar thermal electricity (STE), the International Energy Agency (IEA) predicts Solar PV and STE to represent over 25% of global electricity generation by 2050In their 2014 Technological Roadmaps for solar PV and solar thermal electricity (STE), the International Energy Agency (IEA) predicts Solar PV and STE to represent over 25% of global electricity generation by 2050.

 

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HomeFree – A Healthy Material Resource for Affordable Housing Leaders

Healthy Building Materials as Contributors to Overall Human Health

Healthy Building Contributes to Human Health

What do you think of when you hear the term “healthy living?” A balanced diet? Physical activity? What about healthy building materials? The concept of healthy living can — and should — be extended to include anything that can affect people’s health either directly or indirectly. With this in mind, the impacts of building materials on occupants’ health is a growing concern of building industry professionals because exposure to unhealthy chemicals used in building materials can trigger serious health hazards.

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What’s new in LEED V4 – Commissioning Changes

The sunset date for LEED 2009 project registration has come and gone and all new LEED registrations (or existing registrations that will not submit for preliminary review before June, 30 2021) will fall under the V4 rating system. We are still seeing a trickle of requests for LEED 2009 compliance support for projects that were registered before the October deadline, but those are becoming few and farther between. At the same time, design and construction teams are still wondering what the differences are between the rating systems. So, we are highlighting a few changes to the commissioning requirements in LEED V4 BD&C about which Architects and Developers should be aware.

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Nanogrids: A Whole Building Approach to Distributed Energy Resources

Distributed Energy Resources

Distributed Energy Resources (DERs) are a growing part of the energy landscape in the United States, and they are becoming an ever more attractive opportunity for households, companies, and building owners to gain control of their own energy needs. By 2024, it is estimated that solar PV plus energy storage will represent a $14 billion industry [1]. These resources are installed on the customer side of the utility meter and include distributed generation, such as combined heat and power (CHP) and solar photovoltaics (PV); energy storage assets, such as batteries; energy efficiency and demand management; and building energy management software. When deployed correctly, DERs have the potential to reduce the carbon footprint of the electric grid, increase grid reliability and resiliency, and defer the need for costly upgrades to grid distribution and transmission infrastructure [3,4,7]. (more…)

Power vs. Energy

I can get worked up about units, and this can really annoy people. It especially annoyed students I taught in grad school. I was pretty tyrannical when grading; they always had to include units in their calculations. They could have all the right numbers, but they didn’t get full credit unless all the units were right too. I have no regrets about being such a stickler, because I see tons of confusion about this in the building & energy fields. So here’s a rant about one of my pet peeves: power and energy.

Question: What’s the difference between Power and Energy?

Is this some kind of philosophical question? A koan to meditate upon? No. There’s a real answer (in the engineering world at least). Power is the rate of energy.

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Shifting Perspectives: Experiencing Accessibility Challenges

Katie negotiating a curb ramp and crosswalk with the aid of a cane while wearing vision-altering goggles.

Written by Katie Chevalier, Accessibility Specialist

Last month, I had the opportunity to attend a training session entitled “Shifting Your Perspective: Experience and Plan for Accessibility Challenges,” which was hosted by the Dutchess County Planning Federation. The course syllabus was broken down into two components: experiential and site planning. The goal of the experiential portion of the course was to provide attendees with a variety of simulated sensory and ambulatory challenges and have them navigate the built environment. While the course was primarily geared toward local municipal planning boards, there were valuable lessons to take with me, both in my role as an Accessibility Specialist and as a county resident interested in learning first-hand the challenges that people with disabilities face every day.

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Technically Speaking: Not All Insulation is Graded Equally

About a year ago, I worked along with other HERS raters and the North American Insulation Manufacturers Association (NAIMA, a.k.a. Insulation Institute) to conduct a study on the importance of insulation installation quality and grading.

RESNET, the nation’s leading home energy efficiency network and the governing body of the Home Energy Rating System (HERS® Index) established standards for grading insulation installation.

The grading is as follows:

Grade I— the best and nearly perfect install which includes almost no gaps or compression… what some would call “G.O.A.T.”
Grade II—allows for up to 2% of missing insulation (gaps) and up to 10% compression over the insulation surface area… what some would call “mad decent”.
Grade III—insulation gaps exceed 2% and compression exceeds 10%… anything worse and the insulated surface area is considered un-insulated.

RESNET Insulation Diagram

Source: RESNET Mortgage Industry National HERS Standards

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VRF Systems vs. Electrical Resistance Heaters – A Case Study

Variable refrigerant flow (VRF), also known as variable refrigerant volume, was a concept developed by Daikin Industries in the 1980s. The technology is based on transferring heat through refrigerant lines from an outdoor compressor to multiple indoor fan coil units. VRF systems vary the amount of refrigerant delivered to each indoor unit based on demand, typically through variable speed drives (VFDs) and electronic expansion valves (EEVs). This technology differs from conventional HVAC systems in which airflow is varied based on changes in the thermal load of the space.

The two main VRF systems are heat pump systems that deliver either heating or cooling, or heat recovery systems that can provide simultaneous heating and cooling. These two applications, plus the inverter-driven technology of the outdoor compressors, allow for greater design flexibility and energy savings. In applications where heating and cooling are simultaneously called for in different zones, VRF heat recovery systems allow heat rejected from spaces that are being cooled to be used in spaces where heating is desired. (more…)

Tech Notes: Universal Design vs. Accessible Design

“Isn’t Universal Design just a different term for Accessible Design?” We hear this from architects and designers a lot. While similarities exist, Accessible Design and Universal Design are actually quite different.

outlets, switches, env controls

This image depicts the prescriptive Accessible Design requirements for light switches and operable parts under the Fair Housing Act. Unlike Universal Design, Accessible Design is not intended to be flexible, with little or no room for tolerance.

The term “Accessible Design” typically refers to compliance with Federal accessibility laws and state and local building codes; including the Americans with Disabilities Act and the Fair Housing Act, among others. Accessible Design requirements are based on anthropometric research – or the study of the human body – and are intended to address people with disabilities. Laws and codes that require compliance with Accessible Design requirements include little or no room for tolerance.

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