Building Energy Resilience

During this recent cold-snap in the northeast (where it reached -20F at my house in Montpelier one morning!) you can be sure that HVAC contractors were some of the busiest people around. Inevitably, when outdoor temperatures reach what are called “design-day” conditions, (the days with the highest expected heating or cooling loads a building can experience for its local climatic conditions), HVAC systems are put to the test. It is not uncommon for problems that are not obvious at lower temperatures to suddenly arise-- sometimes leading to system outages, frozen pipes, and worse---exactly when you need your HVAC system the most.

Building Commissioning is formally defined as the “art of analyzing a building’s current performance and implementing measures to reduce the operating cost while improving the functionality of the building’s systems.” Referred to as retrocommissioning when performed for an existing building, the process is designed to ensure the building operates more smoothly, occupants are more comfortable, equipment maintenance problems are reduced and the building owner saves money. In a recent informal survey of commercial building owners our firm has worked with, we were intrigued to find that some owners of existing buildings see the concept of “building commissioning” as too lofty of a goal for an existing building. They seemed to be looking for short-term, practical solutions to their immediate building problems such as occupant comfort complaints and the high cost of emergency maintenance calls. They also often reported not knowing what their HVAC Preventative Maintenance contractor is actually doing, and whether they were receiving the value that they are paying for.

I was cleaning my desk today and came across a napkin on which I’d scrawled some notes about why Building Performance Monitoring and Metrics (BPMM) are important and what the end game in developing building efficiency projects should be.

I was recently involved as a commissioning agent in a new dormitory project where the owner was very clear with the contractor about his expectations for the 80+ fan coil units serving the student rooms. The directive was: don’t connect them to the building’s BMS system (to save money) and they must have temperature set point limits. That’s it. Well, the first requirement was easy but the second, while seemingly straightforward, proved to be more difficult than any of us would have imagined.

The New York Times recently featured a thought-provoking opinion piece on how human body heat may be used to meet the heating demands of modern buildings and other infrastructure. “The Power of a Hot Body” introduces the concept of building occupant body heat as a “green” design strategy that is both novel and low-tech. The blog showcases opportunities for capturing occupant heat from different types of urban buildings and facilities, such as subway stations, train stations, and malls.

HVAC building management systems are not immune from the need for computer security and defensive computing.

Fun and profit can come in unexpected ways to energy efficiency engineers. A couple of months ago while at a jobsite conducting central air handler control testing, there was the inevitable wait-around time. So I stopped to take a look at a central heating hot water plant we commissioned a couple of years ago. It’s a basic system - an all-primary layout with two boilers and variable flow 7.5 horsepower pumps, controlled by a piping differential pressure (DP) control sensor located in a remote section of the distribution piping. The plant serves a few dozen single duct VAV box reheat coils. A pretty typical system.

This engineer recently attended a seminar on “Innovation Implementation: Developing Sales Strategies and Tactics for Growth,” which spent most of its eight hours discussing sales. I found it interesting that this word – sales – caused such a visceral negative reaction in me as well as in some of the other attendees. We did not want to talk about sales and we certainly didn't want to be categorized as “salespeople.” By the middle of the seminar, however, I had a totally different opinion of this word and now realize I am a salesperson! So I better get over my stigmatizing and figure out how I can change this involuntary negative reaction to the idea of “sales.”

I had the good fortune to return to my building engineering design roots in San Francisco to attend Greenbuild 2012. The conference is an amazing confluence of thought leaders, product suppliers and building design and construction professionals gathered around the theme of making the built environment more sustainable. What a cohesive and wonderful concept, right?

A recent Test and Balance (T&B) report for a central air handler made me really question the value of some of our current T&B practices. The system was a conventional variable air volume (VAV) air handler with a return air fan and single duct reheat terminal VAV boxes. The purpose of the T&B process is to adjust and record air handler performance to achieve the specified maximum flow rates.