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.
I spend most of my time focused on improving energy efficiency in buildings. Common recommendations include improving scheduling so that equipment doesn’t run continuously 24/7 or implementing lighting controls so that lights automatically turn off when nobody is in the space. These types of measures can significantly reduce electricity consumption but may have little impact on the building peak demand, let alone the grid peak demand.
There have been many blog posts by Cx Associates’ staff on the benefits of retrocommissioning (RCx), or the best way to begin the RCx process, and even posts on how to increase RCx adoption through efficiency programs. All of these are great posts and I encourage reading them to gain a better knowledge of RCx. Even though many buildings can benefit from RCx, there are some buildings that are actually not good candidates for it. So how do you know if your building is a good candidate for RCx? In this post I am going to give some examples that building owners, operators, and occupants can use to identify whether their facility can benefit from RCx, and determine when it is time to start the RCx process.
The process of designing and constructing a highly efficient, comfortable, and healthy building is challenging enough when the site is in the United States; that becomes a much more difficult endeavor when the site is on the most remote and coldest place on Earth. The design team for the new McMurdo Station in Antarctica approaches the problem with a holistic mindset centered around stewardship.
Recently, I’ve been getting excited about so-called “no touch” energy audits, which employ meter data analytics to assess a building’s energy performance and even make specific recommendations regarding potential improvements, all without requiring the (expensive) “boots on the ground” of a traditional energy audit. This idea has been getting a lot of attention over the past few years as the increasing availability of 15-minute electric interval data has met with the “big data” revolution. In this post, I’m going to take a quick walk through various analysis techniques, moving from coarser to finer granularity.
Back in 2015 I wrote a blog post about ASHRAE Guideline 36 - High Performance Sequences of Operation for HVAC Systems. I referenced a spec my team at Cx Associates wrote for a BAS controls upgrade. Now in 2017, that spec, and the sequences contained therein, have been made into a fully functional BAS controlling 14 air handlers (AHUs), over 90 variable air volume boxes, and the central plant that serves them. Our firm artfully adapted the sequences to meet the needs of the building owner and the function of the building (healthcare) without sacrificing the high degree of complexity which yields the energy savings building automation systems have been promising for decades. After working on this project from specs to implementation, I can confidently say that Guideline 36 can deliver a reduction in energy consumption and improved comfort. The cost (excluding the norms of engineering labor, BAS reprogramming, and commissioning) is primarily paid through raising all ships. Let me explain.
Although electronically commutated motors (ECMs) are specified in efficient buildings, and energy efficiency programs provide incentives for their installation, I only had a cursory understanding of the difference between this technology and traditional shaded pole or permanent split capacitor type motors. What makes ECMs more efficient?