Building Energy Resilience

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.

Most people familiar with commissioning recognize the quality assurance benefits of the commissioning process. Building design and construction projects are inherently complex and there are numerous opportunities for errors and omissions. Commissioning brings the benefit of an expert review to the design documents and installed systems. By identifying design and construction issues for the owner and project team, a commissioning agent helps to improve the overall quality of a building project.

I have blogged before about the energy use of my home and the barriers to addressing it. I’ve begun the journey towards a home that largely reflects my core values of sustainability. After much consideration, site review by multiple builders, excavators and our architect, and standing water in the basement for over a month, we have decided to remove our existing home and build a new house with a goal of net zero energy use.

The toolbox of equipment we use for our building commissioning work changes as building science and standards evolve. As prices for technology continually fall, there often comes a time when equipment you didn’t think you really needed becomes affordable enough that you decide it’s time to take the plunge and invest in it. Having a digital camera 15 years ago was still quite expensive, but now you can get a decent camera for under $200, and most of us have them built right into our cellphones. It’s hard to imagine working as a Commissioning Authority now without such an essential tool as a digital camera. But building commissioning has been around longer than reasonably priced digital cameras, so it must have been possible to provide high quality Cx services without that capacity!

We often write about retrocommissioning of existing buildings in this blog and the benefits to the building owners. To put this in context, I thought I would highlight a recent success story. The following project was the retrocommissioning of an existing four-story 100-year-old building. The building houses retail space on the bottom floor and office space on the upper floors. The measures were driven by comfort issues, control issues and an astute building owner who acted on the utility’s audit of opportunities. After two months of monitoring, this HVAC system’s consumption is showing savings of 80% and payback of the project is approximately 2.5 years. Here are the key elements of this retrocommissioning project.

Hotels can potentially use very large amounts of energy because of the 24/7 occupied schedule for common areas and the necessity to have local controls in each guestroom. Typically, these controls are not monitored and not adjustable unless manually changed at the room thermostat.

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.

At the National Conference on Building Commissioning (NCBC), it was very much apparent that the building commissioning industry is growing and evolving. Demand for commissioning is increasing among building owners and developers, new software tools and mobile apps are being developed to support cloud-based commissioning process management, and municipalities are adopting new commissioning requirements into their building codes, not only for building projects, but also for commissioning providers.

Introduction

The graphical interfaces that connect building operators to the HVAC, lighting, power management, security, and other systems are critical elements of a building control system (A.K.A. BMS, DDC, EMS, but for the purposes of this post, we will focus on the “graphics” portion of the controls server, independent of what the control server is called colloquially). The graphical interface provides the building operators quick access to many pieces of useful (and sometimes critical) information which supports building operation. These include, for example, system status readings, alarms, sensor readings, damper/valve positions, fan/pump speeds, and energy performance metrics. The graphics also provide a means for operators to change setpoints, adjust alarm limits, enable/disable equipment, and do many other functions throughout a potentially large building or campus, right from their desk or a control system workstation.

As Eveline discussed in her last blog post on green banks, there are significant hurdles to gaining the trust and investment dollars of building owners to support energy efficiency investments. Because as efficiency providers we see these investments as certain, we expect owners to share our view and jump at the opportunity to invest in their property and get a great return. As Eveline mentioned, energy efficiency providers have a significant role in getting owners to adopt efficient practices. Here are five rules that can increase the success of energy efficiency programs and providers: