'Go-to' strategies for energy management

05/20/2013


Creating a strategy with CBM technology

Regardless of the type of building envelope you might have, it is critical that it perform as it was designed and intended. To ensure proper construction and performance, adequate testing and maintenance is required. While there are numerous technologies, tools, and methods that are used to test the performance of the building envelope, I have found two particular condition based maintenance (CBM) technologies as my “go-to” preferred method: infrared thermography and airborne ultrasonics.

Having been exposed to CBM technologies being utilized as a predictive maintenance strategy to help identify and correct equipment and component defects, I became aware of the added energy management aspects that these technologies place in the hands of experienced users.

Figure 4: Defective door and window seal. Courtesy: Allied ReliabilityThe power of linking equipment defects and failures with energy management efforts and savings opportunities brings direct, bottom-line value from maintenance. When a defect is present, not only does it put equipment at risk of operational failure, but it also begins performing less efficiently, costing you quality, increased energy usage, and in some instances, increased greenhouse gas emissions.

A building envelope audit should include the use of both infrared thermography and airborne ultrasonics to inspect temperature differences, infiltration, and exfiltration (air, water, gas, and other applicable mediums). By using these technologies, you will be able to not only inspect large areas quickly, but also to pinpoint exact problematic areas in need of immediate attention. Depending on the building design and size, you may be able to inspect the whole building envelope for insulation problems and air leakage. Any gaps in the building envelope where air can enter or exit can cause energy waste.

The two CBM technologies are great tools for identifying such issues due to the natural airflow with different velocities and temperatures. Doors, window frames, and seals should be checked for air infiltration/exfiltration. Penetrations of the envelope, such as water pipes, conduits, and exhaust pipes, should be inspected for proper insulation and sealant.

Figure 5: Building insulation and equipment efficiency opportunities. Courtesy: Allied ReliabilityWater leakage is another problematic issue facing building managers. Where water leaks into a building, it can damage insulation, causing it to lose much of its R rating. Some facilities may have poor insulation, causing heat loss through conduction. Roofs, because of their exposure to water and moisture, can have damaged or missing insulation, causing energy loss.

It’s important to note that not all roofs can be effectively inspected with thermography. Low-slope or flat built-up roofs without significant ballasting are usually good candidates under proper conditions. Similarly, walls with moisture problems or that were never properly insulated can be a source of energy loss identified during a building envelope audit.

Another reason I call these two technologies my “go-to” methods is the simplicity of combining the information with other small pieces of data (i.e., electrical load, air velocity, temperature difference) to quantify the size of the opportunity. These calculations can be done not only in financial terms, but also in terms that environmentalists will appreciate.

Remember, we are identifying energy savings. All forms of energy can be represented in million metric British thermal units (MMBtu), which can then be converted to kilowatt-hours (kWh), then translated to CO2 (the EPA equates 1 kWh as being worth 1.37 lbs of CO2). So, let’s say you identify $18,000.00 worth of savings yielding 353,843 kWh, you can also represent this as 509 barrels of oil, or 24,916 gal of gas, not consumed in a year.  

Moving forward

As great as it is to identify savings and make the adjustments to obtain those savings, you are still left with being able to implement a sustainable strategy so that such inefficiencies do not creep back into your facility. To sustain the savings obtained through a building envelope audit, you will need to deploy a maintenance strategy that includes regularly scheduled maintenance activities that provide an indication to the condition of the item in question so that the appropriate corrective action can be scheduled as it is needed.

I’m going to close with one last point that may seem obvious, but for some unknown reason too often ends the same. While auditing and identifying defects is the first step, it is not and should not be the last step. An audit never adds value without execution. Prioritize the opportunities and begin executing in a way that funds the next item on the prioritized list. When you practice this philosophy, you will quickly understand the value of “paying it forward.”

Chris Colson is director of operations with Allied Reliability, Inc., and is the co-author of the book Clean, Green, & Reliable.


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