Building Energy Resilience

Most people familiar with commissioning recognize the quality assurance benefits of the commissioning process. Building design and construction projects are inherently complex and there are numerous opportunities for errors and omissions. Commissioning brings the benefit of an expert review to the design documents and installed systems. By identifying design and construction issues for the owner and project team, a commissioning agent helps to improve the overall quality of a building project.

At the National Conference on Building Commissioning (NCBC), it was very much apparent that the building commissioning industry is growing and evolving. Demand for commissioning is increasing among building owners and developers, new software tools and mobile apps are being developed to support cloud-based commissioning process management, and municipalities are adopting new commissioning requirements into their building codes, not only for building projects, but also for commissioning providers.

Which energy systems should be included in a building commissioning process if you cannot do them all? Commissioning a building includes a lot of details, and often a lot of equipment. The overall process is generally standardized (see ASHRAE Guideline 0), but the scope of building commissioning can vary a great deal from project to project. LEED certified buildings require commissioning for all energy-related systems associated with HVAC, domestic hot water (DHW), lighting, and renewable energy. Non-LEED building projects may require only HVAC, or may include additional building systems such as the building envelope. But what energy systems can potentially benefit most from a building commissioning process? The precise answer to this question will depend upon the type and quantity of energy systems in a given building project; nevertheless, a reasonable answer to this question may be found in the 2011 Vermont Commercial Building Energy Standard (VCBES).

I recently had the pleasure of attending the 7^th Annual Commissioning Summit for the Northeast Chapter of the Building Commissioning Association (BCA). The BCA Summit provided a great opportunity to discuss important topics of building performance with Northeast commissioning agents and building owners.

While performing a recent functional performance test for a school HVAC system, I discovered something that had gone unnoticed by the contractors and building owner: a motorized damper actuator installed backwards. This damper, one of more than a dozen installed in the building, controls the outdoor air intake for one of the ventilation air handlers. When a discovery like this occurs (and discoveries like this are common in building commissioning), it begs the question: what would the cost impact be if the condition went unnoticed?

The New York Times recently featured a thought-provoking opinion piece on how human body heat may be used to meet the heating demands of modern buildings and other infrastructure. “The Power of a Hot Body” introduces the concept of building occupant body heat as a “green” design strategy that is both novel and low-tech. The blog showcases opportunities for capturing occupant heat from different types of urban buildings and facilities, such as subway stations, train stations, and malls.

I recently visited the construction site for a high performance building project that is pursuing LEED platinum through design-build. The design-build project has all of the bells and whistles that you would expect for LEED platinum: CFL and LED light fixtures with daylighting, energy recovery for ventilation air, and high efficiency heat pumps for heating. Given such a fine collection of green building hardware, I was surprised to find that the high efficiency heat pump heating systems did not meet the state energy code! The particular problem is that the heat pump thermostats do not support temperature setback schedule controls (i.e., scheduled reduction in heating temperature setpoints when the building is unoccupied). A high performance building that does not meet code – how can this happen?!

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.”

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.