Building Energy Resilience

Over the past year or so, I've been involved in several online discussions where the question of how to define what a green building is has resulted in some very interesting comments. A lot of it stems from some people’s view that the USGBC’s green building rating system, LEED, amounts to nothing more than “green washing” and does not result in more sustainable buildings. They argue that because buildings can obtain certification with minimal improvement in energy use over code minimums, it doesn't work.

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?!

Cloud-based building automation represents an exciting opportunity for owners of small-to-mid-sized commercial buildings.

A few weeks ago, in Part I of this post, I examined some examples of the types of commissioning issues we frequently encounter in the field. We looked at condensate pipes with incorrect pitch, maintenance valves on pipes installed 14' off the floor with no way to operate them, and air handlers with different capacities that were incorrectly labeled from the factory. All of these issues, had they not been discovered by a commissioning agent, could have had deleterious effects on building performance. Ready for Part II? Here are more examples of issues we often see in the field.

It's easy to forget to reset your building management system (BMS) or a direct digital control (DDC) system seasonally. Did you overwrite your building management system to forgo night-time building temperature setup due to the hot summer this year? Many buildings had a hard time maintaining their cooler daytime temperatures and therefore cancelled the energy saving nighttime setup program. Forgoing this energy savings was worth the extra hours the building was able to maintain proper temperatures during the workday.

Over the last year, I have become the proud owner of an energy efficient home. Designed and built from scratch, based on passive house principles by a team of local building professionals, construction is well underway, and the house will be completed by the end of the year.

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.”

Following are some examples from the field of things that didn't go so right originally – some worse than others. While we all know none of us is perfect and the unexpected happens, a number of these mistakes in the field point to coordination efforts and installation techniques that, well, maybe weren't given due attention. In field verification, these are the sort of things we are charged with finding before a major problem develops.

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.