In Part One One of this series of posts on RS-485, I gave a high level introduction to the structural and electrical components of RS-485 networks. This week I’ll elaborate on those concepts and delve a little more deeply into some of the industry terminology and how it applies to those concepts. As always, please feel free to drop a comment if you have any questions or want further discussion on any of this information.
For more than a decade, Vermont has been contributing energy efficiency to the New England electricity grid in the Forward Capacity Market (FCM). As a consumer, whether business or residential customer, we think of efficiency improvements as a personal gain, reducing our overhead costs, improving our building’s performance and helping our own pocketbook. Seldom do we think about the impact of energy efficiency on the electric grid, where it actually has a trickle-up impact of our actions onto the bigger picture. But energy efficiency is part of the “supply” for the grid, just like oil, natural gas, solar and other sources. Ben Fowler’s post last month showed a graph of the Generation Fuel Mix of the Philadelphia electric utility. What that doesn’t show is how much is taken off the grid by energy efficiency projects. States take this unrequired energy into account in planning of future energy and infrastructure needs. This has led to avoiding building or expanding substations, transmission lines, and power plants.
Topics: Energy Efficiency
What is RS-485 and what does it have to do with buildings or building controls? If you’re asking this question either you’re just curious, or maybe something isn’t working quite right and you’re Googling to find an answer. Either way, I plan on giving you a high level understanding of RS-485 in this post, and how having a better grip on how it works can help building operators and controls contractors control their building more effectively.
Recently, I was down in Philadelphia visiting family. Being late August, it was 95°F out with a dew point in the low 70’s. Overwhelmingly hot was an understatement, but I do know these things are relative. The residential window air conditioning unit (or as we like to call them in the office, “window shaker” for I think obvious reasons) was running full-tilt and not keeping up. The compressor hadn’t paused for the over an hour. Meanwhile, PJM, the Independent System Operator (ISO) serving the large mid-Atlantic/Central US region including Philly was projecting a 142 gigawatt afternoon peak electric load, with more than 1/3 of this load met with “dirt burners,” more commonly known as coal power plants. See the table below for the generation fuel mix and real time and projected load stats. This kind of info is provided on all the ISOs I’ve checked, which is interesting for us energy geeks. Looking at the data, it made me think I should have just shut the thing off.
Metering equipment, such as light loggers, temperature loggers, and AC current loggers can be very useful tools and sometimes necessary in the world of energy efficiency consulting. They can provide useful data on how equipment is operating and performing. I have written about metering in previous blog posts including one called “EM&V Metering: Right Place, Right Time, Right Duration” where I described the importance of identifying the correct way of deploying meters. In this post I am going to discuss the importance of verifying that meters or loggers are working correctly even before a metering plan is developed or the devices are deployed, as well as the importance of ensuring that the correct sensors are chosen for the application.
Many of the readers of the Building Energy Resilience blog may not know that when I started working in the field of energy efficiency, my focus was on multi-family housing serving people with low incomes. ACEEE recently published this study on the income burden for low-income households. The energy burden is the percent of income paid for energy. It turns out that low-income households have two times the energy burden of the median household – paying over 7% of annual income in energy costs.
While watching coverage of the 2016 Olympic Games in Rio de Janeiro, I started looking into what it took to create the venue which accommodates many of the events. Similar to every Olympic game, Rio had a short period of time to build the extravagant stadiums and the other venues required. In this post, I will discuss what it took to construct this venue and some challenges with this particular location.
Chilled beams have been common in European building HVAC systems for decades, but they are just getting popular in the U.S. These units fit in a drop ceiling or can be hung flush to the ceiling and contain a chilled/hot water coil and, in the case of active beams, a duct bringing in ventilation air.
If you’ve worked in the Building Automation Systems (BAS) industry, you’ve probably heard of LonWorks, BACnet, and Modbus. These three open system networking technologies have been the foundation of most building automation systems over the last decade. They allow devices from different manufacturers to communicate data without issue (most of the time) so that a building’s chiller, boiler, and pumps may all work together as one system to give a building owner an integrated system that enables a high level of functionality.
I love simple concepts formulated using basic math. And even though I love all mathematics, I’ll be the first to admit that my math skills could always be stronger, so I am always trying to learn. I guess that’s why the basic formulas for really complicated concepts really resonate with my inner nerd. The Drake equation as a model for explaining the Fermi paradox is a wonderful example of these. Recently Bill Gates released a short speculation on YouTube regarding energy and CO2. This too really resonated with me as it’s an area where I see our industry really affecting change.