Building Energy Resilience

There are a lot of forces working against achieving the desired performance for new and existing buildings. Complex designs for building system interactions, a lack of equipment maintenance and calibration, turnover of facility personnel, and changes in building utilization can adversely affect building performance. Typical building performance problems include a wide range of significant issues, from chiller evaporator coil freezing to space humidity problems to unrealized equipment efficiency. In an ideal world of building design, construction, operation and maintenance, each new and renovated building would be commissioned, maintained in accordance with the commissioning systems manual, operated per the design intent, re-commissioned to ensure or restore design parameters, and retro-commissioned if the utilization of the building systems change significantly. Unfortunately, the real world and ideal world are two very different places. Most existing buildings have never been commissioned, which creates an enormous opportunity for building performance problems to arise and persist. It is not surprising that we are often called in for “problem solving.”

Many apps for smartphones and tablets have become available for business use as these devices have become increasingly ubiquitous. The range of mobile applications is large and rapidly growing—and apps created for use in the HVAC, building energy performance and energy efficiency fields are no exception.

Last week's post introduced the concept of building for a future of extreme weather events, or why energy performance equals building resilience. I described two buildings – "The Base" typifies common design and construction practices and is slightly better than code* and – "The Ace" which is designed well beyond code in response to issues facing building owners as well as the larger community such as the need to control building operating costs through minimizing the need for energy inputs, the desire to limit greenhouse gas emissions and providing optimum comfort to building occupants.

Energy performance equals building resilience, or so we firmly believe here at Cx Associates. When we named this blog “Building Energy Resilience” Vermont had recently experienced the devastating effects of Tropical Storm Irene. Now, a year later, we continue to seek ways to ensure buildings can survive severe storms with the least possible disruption. According to Environment America, 4 out of 5 Americans live in areas that have been federally designated as having weather related natural disasters in the last six years! Since the vast majority of us continue to emit more carbon dioxide than can be absorbed by natural systems on the planet, we need to begin to look at the tools available that will allow us to survive the impacts of an increasingly dynamic and unpredictable climate.

The Importance of Sensors

A DDC system is programmed to control all of the HVAC equipment in the building. In the central plant equipment, an outdoor air temperature sensor determines if the building is in cooling or heating mode, a flow meter measures how much hot or chilled water is being supplied, and a liquid temperature sensor regulates the hot and chilled water supply temperatures. Within the conditioned spaces, a thermostat measures the room temperature and sends a signal back to the air handling unit to dictate if hot or cold air is required. A temperature sensor and an air pressure sensor determine how much conditioned air is being supplied and at what temperature.

Recently, while reviewing the controls strategy for a large building’s condenser water pumps, I came across something I wanted to share – a simple opportunity for efficiency with no first cost. One, in fact, that increased pumping efficiency by 16% for a large portion of the annual operating hours. To find this opportunity, we considered the off-peak performance of the pumping system, not just its ability to meet peak loads.

It is common knowledge in the architecture/engineering (A/E) professions that buildings consume a large portion of the total energy consumed in the United States (approximately 40 percent)[1]. This awareness serves as an essential motivator for the green building movement and the associated energy efficiency agenda in the A/E industry. As a growing number of building professionals work to improve the efficiency and sustainability of the built environment, it is worth considering how progress toward a more efficient and sustainable built environment may be constrained by industry conventions, standards, and disciplinary boundaries. You can view the industry’s concept of “whole building” energy consumption as one such constraint.

This is the third and final post in a series focused on the connection between energy efficiency and sound control. Actually, the choice of sound control is somewhat arbitrary, and the topic could easily have been energy efficiency and temperature control, energy efficiency and lighting design, or energy efficiency and industrial process.

Fault Detection and Diagnostics (FDD) is an exciting new software tool used to contain energy costs and diagnose energy issues that affect the life and functionality of HVAC equipment and lighting. FDD takes the ability of the direct digital control (DDC) systems a giant leap further into analyzing the performance of these building systems.

This is the second in a series of posts focused on the connection between energy efficiency and sound control. It may seem intuitive that efficient mechanical systems will also be quiet mechanical systems. However, it generally makes sense from cost and performance standpoints to deliberately design with both in mind.