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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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The Value of Commissioning

Written by Jenny Powell, Energy Engineer

What is Commissioning?

Many energy and sustainability programs, standards, and codes require commissioning, including LEED, ASHRAE 90.1, NGBS, IECC, IGCC, the PSEG and NYSERDA’s commercial performance-based incentive programs (see glossary below). As states embrace these codes and enforce commissioning requirements you may ask yourself: what is commissioning and why is it beneficial?

Commissioning agents provide third-party quality assurance throughout the construction process. They review design drawings and submittals, periodically inspect construction progress, witness functional performance testing of mechanical equipment, and ensure that the building staff is trained and ready to operate the equipment after it’s turned over. Commissioning agents work on behalf of the owner to ensure that the owner’s project requirements are met. Most importantly, commissioning improves construction quality and reduces maintenance and energy costs.

The benefits of commissioning are never more apparent than during a retro-commissioning project. While commissioning involves a third-party review of operation during the construction process, retro-commissioning is a third-party review of operations well after construction is complete. Some difficult retro-commissioning projects have shown us how valuable it is to resolve issues when the design intent is still clear (or clearer) – and while the construction team is still onsite!

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