Building Energy Resilience

Retrocommissioning (RCx) or Existing Building Commissioning refer to a technical process that retrofits and tunes building HVAC control systems so that buildings function more efficiently and effectively.  The RCx process has historically included three primary phases:

Pre-Functional testing is a vital step in the commissioning process, where issues can be identified and corrected during equipment installation. It is important to catch issues at this phase in the construction process as issues are often able to be resolved faster, easier and cheaper than if they were identified after construction is complete. Some of the equipment checks may seem a bit obvious and somewhat redundant, but we verify them on every commissioned project—and you might be surprised to learn how often these basic checks uncover deficiencies.

On August 6^th, the Commissioner of the New York City department of health issued an order[1] to all commercial building owners/operators in the City requiring the adoption of a new standard, issued in June 2015 by ASHRAE[2], titled Standard 188 - Legionellosis: Risk Management for Building Water Systems. The order to adopt this standard was in response to the recent Legionellosis outbreak (also known as Legionnaire’s Disease), which has resulted in 12 deaths, sickened more than 100 people, and is believed to have originated from a rooftop cooling tower above a deli in the South Bronx[3].

Engineers and energy managers use many different types of instruments to help identify energy efficiency opportunities in an existing facility. Loggers that have been discussed in previous blog posts are a good way to assess how building equipment performs over time, but I am going to talk about some measurement tools for energy audits and RCx (retrocommissioning) that can be used to instantaneously identify potential issues that can lead to higher than needed energy use.

After completion of an ASHRAE Level 2 Energy Audit, a building owner is faced with the question of how to move on to the implementation phase of the identified energy saving opportunities. The audit report provides estimates for annual energy savings for each opportunity, as well as the simple payback to help determine if the measure is financially feasible. However, the audit does not design a measure in enough detail that a contractor can accurately bid or install the measure so that the savings are realized. Therefore we suggest that the building owner hire a technical consultant (designer or commissioning engineer) to develop a bid document that details the design of the measure. This technical consultant must understand the owner’s goals and expectations for the project.

Back in 2012 I polled our office to find out what mobile apps for HVAC and energy analysis our engineers were experimenting with in the field or back at the office, and summarized those results in a blog post Top Apps for HVAC and Energy Analysis. I also wrote an update to that post in 2013. As you’re undoubtedly aware, things change quickly in the tech sector—and the app marketplace for engineers and commissioning folks is no exception. Given that it’s been two years since I last dug into this topic, I figured it’s time to see what’s new. As with the last posts, I have two caveats before we begin: first, while these apps can be very useful, we still don’t use them for critical analysis, but more as a very powerful back-of-the-envelope equivalent. Critical analysis still happens desk-side for us. Second is that we are an office with a mix of smartphone platforms—a little more than 50% use Apple’s iOS with the balance using Android. We also have a couple of iPads for field use. For simplicity in writing this, I’ve focused on iOS apps—but for most of these, Android versions are also available in the Google Play store.

Recently I have performed new construction commissioning services on a project with a job specification document that was over 1200 pages in length. As you can imagine, it was very comprehensive. However, I found that it was comprehensive in all the areas that it didn’t need to be, and not specific enough where it mattered.

Whether your project is new construction, a retrofit, a major renovation, or a focused building upgrade, my success as a commercial building commissioning provider relies heavily on the active participation of other team members. Despite having clear specifications, providing a thorough building commissioning plan, and explaining the process at a kickoff meeting with the owner and affected contractors, we often find that due to the complexity and fast pace of contemporary construction, team members are unclear as to their role in quality assurance and the commissioning process.

A handful of years ago we worked with a local organization to help upgrade a portion of their building’s legacy pneumatic building controls to a modern building management system (BMS). We performed the project work in a partnership with a local controls contractor as well as with the building owner’s local energy efficiency utility (that provided financial support because the work also provided the opportunity to save a large chunk of electrical and gas energy). The project was overall a big success—saving 20% on the owner’s annual electric bill and 10-15% on natural gas.

Building automation systems (BAS) have been around since the 1980s. They, like any other computer based technology, have evolved several times over parallel to the widespread adoption of information systems across all industries. Their key benefits are understood to be primarily HVAC system control, automation, and HVAC system optimization. But with the advent of systems being more distributed and more open over the last decade, there has been one benefit that gets overlooked a lot: BAS trend data.