Tackling Energy Consumption within the Existing Built Environment: Energy Audits and Re-Commissioning

Ken Urbanek , Director of Engineering
MKK Consulting Engineers, Inc., Denver

Urbanek BW

In terms of energy consumption, our current building stock accounts for 47.6% of all the energy consumed in the U.S. and 74.9% of all of the electricity produced in the U.S. These are staggering terms. It has been said that approximately 70% of the building stock that designers will touch in our working careers has already been built. This means that in order to tackle a significant reduction in our current energy consumption, thus reductions in CO2 emissions and a reduction in fossil fuel use, those of us within the industry must focus a large portion of our attention to the existing built environment. The good news is that over these next 20 years, the built environment community will have the chance to tune-up, renovate, upgrade and make major improvements to the energy use of these existing buildings.

First and foremost, the current building operation should be thoroughly reviewed through an energy audit and/or re-commissioning process. Once the results of these investigations are completed, it may be determined that more capital intensive improvements to fix major systems deficiencies are required.

When it comes to reducing building systems energy, the first step should always be to thoroughly review the building as it is currently operating. Hiring a professional energy services engineer to conduct a thorough ASHRAE type Energy Audit is recommended as it will detail specific energy uses within your building. ASHRAE has three classifications of energy audit efforts: Level 1 – Walk-Through Analysis, Level 2 – Energy Survey Analysis, and Level 3 – Detailed Analysis of Capital Intensive Modifications. Through discussions with your professional along with analysis of available utility rebates to implement can be determined. These audits are the first step towards identifying energy efficiency measures (EEM) that can be implemented to reduce operational costs in the future.

If a thorough ASHRAE type Energy Audit cannot be performed, at a minimum, an in-depth due diligence can be another option to consider. The due diligence process relies on your professionals experience and judgment to make recommendations for building improvements through a shortened building review process.

One common EEM that comes from the audit process is to hire a commissioning professional to implement a building re-commissioning effort. Re-commissioning focuses on providing a thorough tune-up for the building systems that are already in place. This optimization process can often account for a 20% reduction of current energy costs by addressing and fixing low to no cost problems.
Both energy audits and re-commissioning can start to development more enhanced EEMs that start to tackle existing systems deficiencies.

All of the costs associated with the methods of energy reduction noted here (audits and re-commissioning) can be partially offset through rebates provided by most local utilities. These rebates can often provide enough incentive to push a project forward vs. it not moving at all. Be sure to review these closely with the utility to ensure that the rebates are maximized.

When it comes time to reduce energy costs, start by getting a good understanding of the existing building through an audit and address the low hanging fruit by optimizing the existing systems through re-commissioning. With a team of professionals on your side, you too, can help drive energy efficiency in today’s existing buildings over the next 10 to 20 years.