Building Energy Resilience

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.

One of the first things I became aware of when I joined Cx Associates is that sustainability is a way of thinking. I learned efficiency and judicious use of resources can be approached on many different levels, from choosing a more efficient clothes dryer, to finding alternatives for drying clothes, such as line or rack drying. All efforts toward sustainability are important, and a large impact can often be had for little effort and inconvenience. Multiplied by dozens or even hundreds and thousands of people, a seemingly small change can go a long way.

Benchmarking is on my mind. I've been reviewing the project submissions for the Vermont’s Greenest Buildings Awards and am so impressed by what some teams are achieving in designing and operating energy efficient buildings that use far less than “typical” buildings. The only way we can know how good (or bad) our buildings are is to benchmark them. Benchmarking is a process where we calculate the annual energy intensity (kbtu/sf/yr) – adjusted to reflect weather variations from “normal” which is known as “normalizing” the data for weather. This number is like the building’s miles per gallon and can be used to find out whether the building is an energy sipping hybrid, a typical mid-sized sedan or a guzzling SUV.

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.

Over the weekend I connected a tank of the refrigerant R-290 to my gas grill, fired it up, and had some delicious fresh grilled Vermont sweet corn on the cob. Very tasty.

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.

A Performance Contract with an Energy Services Company (ESCO) can be a powerful tool to enable a business to improve the performance of their facility without requiring money upfront. An ESCO assesses a facility’s energy efficiency opportunity, manages the improvement implementation and guarantees the energy savings will be greater than the cost of the project. In my recent blog post, ESCO: Energy Efficiency Investment with No Money Down, I describe the process of a Performance Contract and state “the ESCO assumes the risk of under-performance.” In recent months, however, the cost of natural gas has decreased substantially and many existing Performance Contracts are seeing negative savings for which the building owners are responsible.

The Vermont Green Building Network (VGBN), the Vermont Chapter of the U.S. Green Building Council (USGBC), recently decided to offer an award to recognize sustainable buildings in Vermont. As a VGBN Board Member, I reached out to peers during the award development process and heard a common theme – we need to recognize buildings that have proven energy performance. People stressed this approach because the owners who are hiring architects, engineers and other consultants often can’t tell which ones have the unique expertise and skills that will result in truly high performance buildings. Many owners perceive all professionals who submit proposals as qualified and they use price as the means for selection.