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. Read more

Tech Notes: Universal Design v. 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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Which LEED Rating System Do I Use? Part 1: NC versus Midrise

Here’s a question our clients often ask: “I’m building a new residential building, should I use LEED for New Construction (NC) or LEED for Multifamily Midrise?” The answer isn’t exactly simple, especially with the introduction of new credit requirements in LEED v4 and the fact that USGBC allows project teams to choose between the two rating systems. Ultimately, it’s often a difficult decision based on the goals and final design of the project. So, in an effort to help clear up the confusion and possibly make the decision a little easier for you, we decided to break down a few scenarios that highlight key differences between the rating systems that may not be apparent upon first glance. In this first installment, we’ll start with a smaller multifamily building to get a sense of the essential differences between the rating systems and begin to understand the critical decision-making points.

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Tech Notes – Medical Diagnostic Equipment and Accessibility

By Victoria Lanteigne, Senior Accessibility Consultant

The United States Access Board recently issued new standards under Section 510 of the Rehabilitation Act of 1973 for Medical Diagnostic Equipment (MDE). The Proposed Standards provide design criteria for MDE such as examination tables and chairs, scales, radiology equipment, mammography equipment, among other medical equipment. The new accessibility requirements, “establish minimum technical criteria that will allow patients with disabilities independent entry to, use of, and exit from medical diagnostic equipment to the maximum extent possible.”

The Proposed Standards provide technical criteria that will facilitate the use of equipment for people with disabilities in the supine, prone, side-lying, and seated positions. A few key requirements from the Proposed Standard are following:

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