Building Energy Resilience

Introduction

We receive dozens, probably closer to a hundred commissioning requests for proposals (RFPs) every year. The quality, content and requirements are as varied as one might expect. Jennifer Chiodo posted some thoughts on how one can identify quality commissioning services and I’d like to take this opportunity to suggest how one might develop an RFP for commissioning services.

Introduction

In my last post I cited three examples of incomplete or incorrect control programming that all would have had negative effects on building operations or equipment life expectancy. In this post, I want to focus on one piece of equipment, a rooftop ERU (energy recovery unit) and, more specifically, on the graphic page for that ERU. This is another prime example of the controls not being done even though the contractor had said they were complete.

Building controls are always the last thing to get done on a project – at least on the mechanical side. They basically have to be. You can’t control what isn’t there and until the systems and equipment have been fully installed, started and balanced, the controls contractor can’t finish. As a result, controls contractors are often rushed and expected to complete, say, two weeks of work in two days. The result is often less-than-complete controls or a system that hasn’t been fully vetted which, sooner or later, results in a confused or unhappy building owner or occupants.

We are wrapping up the commissioning of a water source heat pump system for a 120+ room hotel. Our involvement began in the design stage when the initial concept was to use condensing boilers to heat both the domestic hot water (indirectly) and heat pump loop. While this is a fairly typical scenario, especially in the hospitality industry where first cost is typically given a very high priority, it leaves a lot of the boilers’ potential energy efficiency on the table.

As an engineer myself, I was struck recently by fresh evidence of the pervasive challenge of communicating technical information effectively. I attended a building conference where the focus is designing better buildings and one common thread emerged. “Death by PowerPoint” is alive and well in the building and design industry.

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.

Over the past year or so, I've been involved in several online discussions where the question of how to define what a green building is has resulted in some very interesting comments. A lot of it stems from some people’s view that the USGBC’s green building rating system, LEED, amounts to nothing more than “green washing” and does not result in more sustainable buildings. They argue that because buildings can obtain certification with minimal improvement in energy use over code minimums, it doesn't work.

A few weeks ago, in Part I of this post, I examined some examples of the types of commissioning issues we frequently encounter in the field. We looked at condensate pipes with incorrect pitch, maintenance valves on pipes installed 14' off the floor with no way to operate them, and air handlers with different capacities that were incorrectly labeled from the factory. All of these issues, had they not been discovered by a commissioning agent, could have had deleterious effects on building performance. Ready for Part II? Here are more examples of issues we often see in the field.

Following are some examples from the field of things that didn't go so right originally – some worse than others. While we all know none of us is perfect and the unexpected happens, a number of these mistakes in the field point to coordination efforts and installation techniques that, well, maybe weren't given due attention. In field verification, these are the sort of things we are charged with finding before a major problem develops.

Recently, while reviewing the controls strategy for a large building’s condenser water pumps, I came across something I wanted to share – a simple opportunity for efficiency with no first cost. One, in fact, that increased pumping efficiency by 16% for a large portion of the annual operating hours. To find this opportunity, we considered the off-peak performance of the pumping system, not just its ability to meet peak loads.