I recently attended the Performance Evaluation Methodology for Building Occupancy Sensing Systems for HVAC Controls workshop, which followed the annual ASHRAE conference that just wrapped up in Kansas City, MO. The workshop focused on one of ARPA-E’s research programs called SENSOR (Saving Energy Nationwide in Structures with Occupancy Recognition), and brought together a diverse group of individuals, including researchers from national labs and universities, industry representatives, design engineers, and other interested parties.
Sometimes certain parts of the commissioning and retrocommissioning process can seem trivial to both the contractor and the commissioning agent. Of course, the process involves some important and significant checks, such as ensuring the piping design detail matches the as-built piping, and that the specified ductwork sizes match the as-built ductwork size. But the commissioning process also deals with some of the finer details that may not seem as consequential or that have already been checked by multiple parties. So, why would the commissioning agent also need to check it again? In this post I am providing a couple examples of real-world commissioning issues that we’ve found. Each is an excellent reminder of why the seemingly minor commissioning verification steps are still required and important, even though they may seem inconsequential.
As someone very new to the engineering world, I’ve learned a lot in the last few months about the impact that engineers can have on climate change. I came to Cx Associates and the world of commissioning in a rather round-about way. My background is in molecular genetics, specifically lung cancer research, but when I moved to Burlington this past summer, I decided to pivot in my career path. I’d found myself desiring more and more to move into a field that was doing some good for the world. I know, I know, many would say “Hey! Cancer research is good for the world!,” and I certainly don’t deny that, but what good is finding new cancer treatments if there isn’t a planet that can viably support the patients those treatments would be for? As I’m sure many of you heard or read in the news some months ago, the Intergovernmental Panel on Climate Change (IPCC)’s 2018 Climate Report showed that “global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate” (something some climate scientists have argued is a conservative estimate). This will have devastating effects on people’s lives, and not only in poorer nations of the world – the Fourth National Climate Assessment released by the U.S. Global Change Research Program in November 2018 predicts U.S. economic losses due to climate change in 2090 as $280-$500 billion/year. These reports cemented my feelings in the weeks and months after I began at CxA, but I had already felt myself pulled towards the idea of working for a company or organization that was doing solid, on the ground work to combat climate change. I did not expect that pull to land me at a consulting engineering firm.
When people ask me what I do for work, I generally tell them I’m a building systems engineer, with a big focus on making facilities more energy efficient and comfortable for occupants. One common part of my job entails going to a building to perform an energy audit or assessment. During these visits, we follow the same straightforward outline:
- Walk through the site
- Inventory all energy-related equipment including lighting, mechanical systems, building envelope, etc.
- Speak with the building operator about how they run the building
- Ask the building owner, occupants, and operator about and any issues or concerns they have regarding maintenance, equipment that is not working properly, or comfort problems.
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: Planning, Investigation, and Implementation.
As the newest engineer to join the Cx Associates team, I have had the immense pleasure to be able to approach buildings from a different angle than in my previous work experience. In my former work as a mechanical design engineer, the focus was on current building technologies and keeping up with the most cutting-edge designs for our systems and buildings. Don’t get me wrong, looking to the future of efficient building technologies is tremendously important, but as someone who is concerned about the current state of the environment and ensuring there’s a habitable world for generations of living things to come, I found it hard to believe that new buildings alone are capable of being more than a small drop in a big bucket. After all, there are only a small number of new buildings built each year compared to the vast existing building stock. A quick look at the numbers from the Commercial Buildings Energy Consumption Survey (CBECS) by the US Energy Information Administration (EIA) will tell you that of the total data set, only about 18% of commercial buildings were built in the most recent 12 years surveyed. (https://www.eia.gov/consumption/commercial/data/2012/bc/cfm/b8.php)
Space upgrades are necessary to ensure that older buildings remain safe, functional, and cutting-edge for the users. As part of my role as an owner’s project manager for a large hospital, one of my recent projects has been upgrading the finishes of several operating rooms. This post discusses the coordination and construction effort involved for such a project, as well as some potential challenges.
The best time is now to replace an old R-22 refrigerant system with an environmentally-friendly alternative.
For better or for worse, we no longer live in the days of hairspray. Our ’do’s style may have suffered slightly, but our environment has benefited greatly. When the Montreal Protocol was signed by the United States in 1987, it set a goal of reducing emissions of ozone depleting chemicals, and it has experienced some success…I hope you all celebrated World Ozone Day this month on September 16th! Many people may be blissfully ignorant of the changes to their aerosol products in the last 30 years thanks to the Montreal Protocol, but in the HVAC/R industry, we’re continually aware.
Optimal start/stop (OSS) is available as an out-of-the-box function in almost every HVAC building automation system sold on the commercial market today. Folks toss the term around with a very loose understanding of what it means. PID controls suffer the same dilemma. When you ask any industry professional to define OSS, you’ll get this generic and common response (Figure 1):
Today there are a multitude of energy metering devices (e.g. data loggers) available to enable the analysis of building systems functionality. There are many different types of data loggers, each with a different purpose. To get the most from your building using energy metering, you need to narrow your options with your overall goals in mind. Before we install meters on a system, whether it’s an electrical system, HVAC system, or domestic hot water system, we must first determine what type of data we need and what the data will be used for. With this information, we put together a metering plan that will produce the data necessary for the analysis. I am going to provide two specific examples of systems/equipment we metered, including why we were performing the metering, how we did it (what types of meters), and what the findings were. Both of these examples showed the equipment being metered was not working as intended.