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.
When I started in the energy efficiency profession 20 years ago, the object of my job was to reduce electric demand on the grid. This was to be accomplished through energy efficiency and a strong emphasis to fuel switch equipment from electric to fossil fuels (specifically electric heat to natural gas or oil heat). At the point of use (our building), traditional electric heat is 100% efficient, meaning 100% of the electricity within our building is transferred into heat within our building. But the electric generation (at the power plant), and the transmission, and distribution process makes the entire process about 30% efficient. This means an oil or natural gas heating system, operating at approximately 80% efficiency at point of use, is inherently more efficient than traditional electric heat given the current electric grid generation mix. Heat pumps, however, have changed this calculation, with heating efficiencies of over 300%. Thus, the world is changing back to electric heat through heat pumps (refer to Gretchen’s blog from February 2017, Heat Pumps Catered to Colder Climates; Will Increased U.S. Adoption Continue?). Is this a good thing? ‘Experts’ seem to agree that it is, but I have been curious to do this calculation myself as adding electric load to the grid goes against my deep-rooted mindset.
The floor was packed with a bustling crowd, filled with people from every branch of the Heating Ventilating and Air Conditioning (HVAC) industry. They were making contacts, meeting friends, and checking out the latest and greatest technologies. There were young professionals eager to experience what the industry has to offer. They were seeing the current state of the art but also thinking about the future as they pass vendors strutting their stuff. Everywhere you looked, there were folks dressed smartly, representing their products with a smile and a handshake. Everyone was boasting about their latest tech, itching to perform the ritual tchotchke handoff in the hopes that someone will remember their product and give them a call after the dust settles. All of this was housed at a convention center so large it has its own bus port and ceilings so high they make your local Walmart superstore look like a tent at a county fair.
Vision without action is a daydream. Action without vision is a nightmare.
I received an email with this tag line and it struck me as profound. A business cannot operate efficiently and effectively without a clear vision of its future and a road map of the steps to obtaining that vision. A business owner must constantly ask: what aspects of the business are going to change, how are they going to change, and what is going to stay the same? Am I riding on top of the wave that is my business paradigm, or am I getting toppled over by the wave and left behind?
I have repeatedly blogged about my concerns with the current and future energy codes because the codes are not keeping up with technology for lighting efficiency (see my previous blog posts titled “Why are Lighting Energy Standards Decreasing” and “More Issues with the Energy Code – Lighting is Running Rampant”). The graphs below, developed by our friends at Optimal Energy, show some comparisons of Department of Energy (DOE) predicted efficacies for lighting technologies and the efficacy needed to meet code for some common space types.
It can often be an afterthought as to how much outdoor air (OA) is actually being drawn into a hospital through air handling equipment, but maintaining proper outdoor air volume is a vital part of achieving effective infection control, as well as meeting space pressurization requirements. Proper OA volumes are also a metric that can be reviewed for non-compliance during Joint Commission audits. The amount of outside air that a hospital’s air handling equipment should introduce into the building is defined by the ASHRAE Standard 170, which was discussed in one of our previous blog posts, Optimizing Air Handling Units for Healthcare. As we pointed out in this prior post, an airflow station, when properly selected and installed, is an effective piece of hardware which can be used to monitor this outside air quantity (typically in cubic feet per minute), and the data provided by this meter can be very useful in a healthcare setting.
The Better Buildings by Design conference took place a couple of weeks ago here in Vermont. The two-day conference brings together contractors, utility representatives, architects, engineers, and other energy professionals to discuss energy efficiency, durability, and operations and maintenance for residential and commercial buildings. It included sessions across multiple subject tracks, workshops, and a trade floor with many exhibitors, and offered a great opportunity for learning about new developments in the field and networking with fellow energy nerds. Cx Associates had a strong attendance at the conference, with several of us presenting in multiple sessions.
I attended six talks, a few open panel discussions, an ASHRAE GPC36 Committee meeting, and topped the days off by making new friends and “nerding out” over HVAC. I chose to attend panels and presentations that had to do with controls, integration, and grid management because that’s where I believe we can easily continue to chip away at excessive energy consumption due to poorly controlled building HVAC systems.