Building Energy Resilience

Few documents are as important to commissioning providers as the Owner’s Project Requirements (OPR), it is our building block, our map and compass used to navigate the project to success from pre-design to occupancy. It's obvious this is an important document to us at Cx Associates, too. A search of our website resulted in three full pages of hits of the acronym. We’re know this document inside and out, from developing them, to reviewing pre-existing OPRs, to gently reminding contractors and designers that the document exists, but until about a year ago there was only one way around an OPR.

Basics of steam coil and face and bypass operation

Many air handling units in colder climates are equipped with steam heating coils. These coils use control valves to modulate the flow of steam to the coil. Due to the low mass of water in a steam coil, it has a higher propensity to freezing when conditions are right. One of the neat ways we’ve design around this is to use a Face and Bypass (F&B) damper arrangement to allow the coil to have maximum steam flow to prevent freezing. The F&B dampers direct a portion of the airflow through the steam coil and another portion bypasses the coil in order to achieve the necessary discharge air temperature and prevent a freezing airstream from damaging the steam coil. Pretty neat, huh?

As we are all learning to adjust to life with COVID-19, many areas are considering re-opening schools for the coming school year. Although many teachers are finally starting to unwind into a stranger-than-usual summer break, now is the ideal time to get a jump on adjustments to school operations to make in-person education as safe as possible for students, faculty and staff alike.  

In this time of global crisis, it can be hard to cope with some of the new realities we’re all being faced with, whether it’s experiencing isolation due to social distancing, fearing for yourself or loved ones, or dealing with the virus’ economic impact. As a business that strives to engineer a future where buildings are better for people and planet, we can’t help but notice the ways this crisis reflects global warming’s looming themes: it’s going to affect everyone, it has dangerous consequences, and it takes a global effort to combat. While I only have the emotional bandwidth for one global emergency at a time, the environment is still in the back of my mind, and I can’t help but think of the ways the virus and our environment are inextricably linked.

Thanks for following the second part of the ground coupled heat pump design. If you haven’t already, now’s a good time to go back and read Part 1. In the first part of this post, we discussed the importance of understanding thermal imbalance in a ground source heat pump system and the longevity impacts associated with an imbalanced system. Despite the issues associated with a thermally imbalanced system, there are ways to address building loads with additional technology that will further enhance the performance of the ground-coupled heat pump system, as well as provide long term performance.

The ground source heat pump is a wonderful technology that will be vital in achieving energy efficiency goals this century. This technology isn’t new, but it is beginning to become more accepted as a viable solution for large scale, high efficiency HVAC performance. There are two main types of ground source heat pump systems: those that are “Ground Water” (also called Open Loop) and those that are “Ground-Coupled” (also called Closed Loop), see Figure 1 below. In either case, the water from the ground is pumped to a heat pump, where heat is either extracted out of or rejected into the ground and moved into or out of the conditioned space.

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)

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.