Application Story

Ruairi Barnwell of Chicago-based Building Momentum Group discusses how his company uses data loggers for holistic building assessment. Barnwell also describes the Building Energy Quotient pilot program launched by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). He was among 17 engineers nationwide selected to participate in the pilot program. Barnwell assessed Building EQ in the state-owned John W. McCormack Building in Boston.

Building Momentum Group provides a unique service in that your building assessments cover a lot more than just energy. What differentiates BMG from its competitors?

We conduct three levels of building assessment, each of which exceeds the basic requirements of an ASHRAE Level I, II, or III audit respectively.

Similar to an ASHRAE commercial building energy audit, our building performance assessment involves a detailed look into the building’s energy use. But we also assess the indoor environmental quality, resource efficiency, and occupant comfort. And we provide a detailed report of findings and suggestions for achieving Energy Star, LEED (Leadership in Energy and Environmental Design), High Performance, and Net-Zero Energy status.

We combine our building science, energy modeling, and commissioning skills to provide building owners with a unique perspective on how their buildings operate. This enables us to make holistic recommendations for optimizing the building's performance and helps lay out a sustainability road map that fits an owner’s budget.

If capital improvements are required, our modeling analysis explores the investment opportunities of selected options and provides the building owner with the information required to make a confident decision about the risks and rewards of moving ahead with building performance improvements.

We present the business case, providing fiscal strategies as they relate to suggested capital improvements and detailed backup information that provides confidence in our recommendations.

What factors do you take into account to determine the Indoor Environmental Quality?

We assess everything from the indoor air quality, the lighting quality, and the building acoustics to the building envelope, which could also be contributing to IEQ problems. Basically we review all of the factors that may be affecting the building occupants’ comfort, well-being, and productivity.

How do you gather this information during your assessment?

We discover a lot through conversations with the building’s engineering staff and also through our own experience with building systems and how they interact. There’s no substitute for that. But we also use Onset HOBO data loggers to trend key metrics, such as temperature, relative humidity, carbon dioxide, and lighting levels. We place the data loggers in representative spaces throughout the building and typically leave them in place for seven to ten days.

The information we can compile from these data-trending devices gives us excellent insight into how the building is operating and where the building stands in terms of indoor environmental quality.

We condense the data into key dashboards that the building owner can appreciate and understand. We can easily tell, for example, when the CO2 or temperature levels stray outside of ASHRAE prescribed comfort limits. Once we see a specific metric is outside of the banded limits we can usually make very accurate deductions about the cause. For example, a high concentration of CO2 in a space may mean that the system is not responding quickly enough to an increase in the number of occupants in that zone. This would indicate to us that we should review the controls and actuators for the air distribution system serving that area. These types of system anomalies, which affect the indoor environmental quality, typically go unnoticed during a standard building energy audit. But we are able to pinpoint and resolve deficiencies like these very effectively.

How did you become involved in Building EQ?

ASHRAE asked its members to submit qualifications to be considered for the role of provisional assessors for the In Operation rating pilot for the Building EQ program. I was chosen as a provisional assessor because of my background in engineering and building science, my experience working with existing buildings and rating systems (such as LEED and Energy Star), my knowledge of the ASHRAE standards, my familiarity with the European Union labeling programs, and also my industry credentials, such as being an ASHRAE-Certified High-Performance Building Design Professional.

ASHRAE is actually developing a Building Energy Assessors certification specifically for the Building EQ program’s operational rating. And earlier this year ASHRAE launched a Building Energy Modeling Professional certification specifically for the Building EQ program’s asset rating.

How does Building EQ differ from the federal Energy Star label?

The Energy Star program provides building owners with a tool for monitoring their energy consumption and recognizes the top 25 percent of buildings. But because its scale is based on a comparison with Commercial Buildings Energy Consumption Surveys (CBECS) data for existing commercial building stock, there is no easy way to recognize buildings that reach toward extremely low energy use.

The nice thing about the Building EQ program is that it provides greater differentiation for high performing buildings and puts a bigger emphasis on the top performers. ASHRAE has intentionally made it a tough scoring system as part of its aggressive energy efficiency goals and to ultimately drive the market towards net zero energy operation.

The Building EQ program should provide an easier scale to convey a building’s energy use to the public than Energy Star currently does. The label itself will be the most visible aspect of the program. It will be simple to understand and targeted at the general public. It could be used for posting in a building lobby and could satisfy compliance with many of the programs being developed at the state and local level requiring display of energy use.

Another key difference between the two rating systems is that unlike Energy Star, the Building EQ rating mandates an on-site assessment, which will provide the property owner with building-specific information and recommendations that can be used to improve the building. The on-site assessment will verify that the indoor environmental quality of the building has not been compromised in the pursuit of energy efficiency and energy savings. The assessment will include actual measurements to ensure that the building complies with ASHRAE’s standards 55 & 62.1 which address Occupancy Thermal Comfort & Ventilation for Indoor Acceptable Air Quality respectively.

How will Building EQ fit in with LEED certification?

The Building EQ program partly came about to examine the concerns that had been raised in the industry regarding the energy use of buildings that receive a LEED rating. There appeared to be a disconnect between how these buildings were designed and how they actually operated. The US Green Building Council has been exploring ways to improve the performance of LEED buildings, relative to their design, to address these concerns.

Future versions of LEED will have some form of ongoing assessment of the characteristics that make up a green building, such as energy use, water efficiency, and indoor environmental quality. The 2009 version already requires submitters to provide access to energy and water-use data.

The Building EQ program could be an excellent tool for the ongoing assessment of energy use and indoor environmental quality for LEED rated buildings.

How did you assess the Building EQ of the McCormack Building?

The first thing we did was analyze the utility bills from the previous two years to determine the building’s Energy Utilization Index (EUI). We also documented the building’s characteristics, such as gross floor area, total conditioned floor area, etc.

Then we sat down with the building’s operations management staff to discuss the building systems and how they operate and interact on a day-to-day basis.

As part of our building assessment, we took measures in five representative zones in the building, checking CO2, relative humidity, temperature, and light levels to assess the comfort of the occupants in these spaces.

To confirm compliance with ASHRAE Standard 55-2004 (which pertains to Thermal Environmental Conditions for Human Occupancy) we measured air movement to assess thermal uniformity and developed the radiant temperature asymmetry for each space.We also provided a quick, overall evaluation of the lighting quality of the building and took spot measurements of luminance levels in the representative spaces to determine if the lighting system performance was adequate. To confirm compliance with ASHRAE Standard 62.1-2007 (Ventilation for Acceptable Indoor Air Quality), we measured the volume of outdoor air at each of the intakes on the air handling units serving the representative zones. We then verified compliance with the Ventilation Rate Procedure in Standard 62.1. We calculated the actual Building EQ rating by determining the ratio of the normalized energy use of the McCormack building to the median energy use of its building type, as specified by the Energy Star Target Finder Program.

What did you find during your assessment of the building?

We found that the operations staff at the McCormack building were doing an excellent job implementing their own energy-conservation measures, given their budget and manpower constraints. They had already addressed a lot of the so-called low-hanging fruit and had achieved significant energy savings over the past four or five years.

The most obvious constraint to energy efficiency with the building is the dated single pane and metal frame building envelope, which is inherently inefficient. Other big challenges they face are an outdated pneumatic controls system and an aging air distribution system.

All of these factors combine to make the operation of the building a daily challenge, which the team is meeting by adjusting the systems manually to keep the occupants satisfied.

However, there are areas that consistently experience problems and have regular hot and cold complaints. These were the areas we focused on during our assessment.

How important will Building EQ become in improving the nation’s building stock?

The data that will be gathered through the Building EQ program will become critical in addressing how the nation’s building stock can reduce its energy use.

Mandatory energy disclosure labeling requirements are already in place in the European Union, California, and Washington, DC. The Building EQ program is set to become a powerful tool and a consistent model as other energy disclosure mandates are introduced across the nation.

For more on ASHRAE’s Building EQ program see