Tag Archives: bms

5 Ways Going Green is Great for Buildings

A recent study of facility management executives found that 5 percent had certified a green building before 2012, but that 29 percent plan to certify one in 2013. That growth in the market for green buildings will ripple through the industry. Over the next ten years, buildings will become more grid-responsive, resilient, efficient, energy-positive and networked.

Grid Responsiveness
A survey indicted that 14 percent of U.S. building organizations currently participate in demand response programs. Building energy consumption can be continuously adjusted throughout the day to reduce demand at critical times.

To withstand natural disasters, there is an important role for distributed energy systems and smart building controls.

“The new approach would define policies and technical requirements for how to incorporate smart grid technology, microgrids, building controls and distributed generation, including CHP, with two-way flow networks into the grid. … This approach would allow building controls to provide a minimal level of service such as basic lights and refrigeration during emergencies,” the Hurricane Sandy Rebuilding strategy noted.

Building efficiency improvements in lighting, HVAC and controls are the most popular improvements and more than two-thirds of organizations have addressed these in the past year.

There is a growing trend in building design to go net zero or energy positive. In fact, California has included net zero as an energy goal for 2030 for commercial buildings. The U.S. Department of Defense and the U.S. Army have also set energy-positive goals.

Smart buildings provide data and information needed to measure, monitor and manage building performance.

View Full Article in: Rocky Mountain Institute

Deferred Capital Renewal Can Be Used To Justify HVAC Upgrades

Facility managers should determine if deferred capital renewal should be part of the analysis to justify large energy upgrades.

An example of a deferred capital savings is the evaluation of installing a new boiler as compared to maintaining the existing boiler. A 20,000 pound per hour (pph) boiler with mud and steam drums (the heart of the boiler) may be in good condition, but the boiler tubes could be thinning and need to be replaced. The cost to retube and recase this boiler is approximately $350,000. In this example, the recasing and retubing of the boiler will not increase the boiler efficiency of the system. Also, the existing boiler is assumed to have an efficiency of 75 percent.

A newer boiler with stack economizer could have an efficiency of 85 percent and the cost to install this boiler is approximately $1.2 million. In 2012, the average national cost for natural gas was approximately $8.15 per thousand cubic feet or approximately $8.00 per million BTU. Assuming the boiler operates at full load for 2,500 hours, the increase in efficiency would save the facility approximately $62,000 per year in natural gas costs. The simple payback to replace the boiler without the deferred capital is 19.4 years (capital cost of $1.2 million and an annual savings of $62,000 per year). However, if the analysis took into account the $350,000 cost to recase and retube the boiler, this would reduce the capital cost from $1.2 million to $850,000 and the corresponding simple payback would be reduced to 13.7 years. The cost to recase and retube the boiler should be included in the analysis because this work needs to be completed to maintain the operation of the system.

Another example is the replacement of a 30-year-old water chiller. Typically, chillers installed at this time were constant speed units. Based upon ASHRAE numbers, the average service life of a water-cooled chiller is 23 years. That does not mean that, once a chiller has been in service for 23 years, the unit will fail, but rather that a plan for the chiller replacement should be in place based on that average service life. A 450-ton constant speed water-cooled chiller has been designed to have a chiller efficiency of 0.70 kW/ton, but because of the age of the equipment the chiller could be de-rated to an efficiency of 0.81 kW/ton, assuming a 0.5 percent per year degradation. A variable flow chiller unit can be selected to operate with an efficiency of 0.50 kW/ton. Based upon the unit operating at full load condition for 1,500 hours and an electric rate of $0.08/kWh, the annual savings for installing the VFD unit is approximately $16,700 per year.

The cost for the new VFD chiller system is estimated to be $250,000. This would correspond to a simple payback of close to 15 years. If the analysis included the cost to replace the unit with a constant speed chiller (assuming the cost of $203,000), the difference in capital costs is only $47,000 and the simple payback would be reduced to 2.8 years. Even if the analysis assumed that the constant speed chiller was installed with the original efficiency (0.70 kW/ton) the simple payback is still 4.3 years.

It is difficult to identify the deferred capital savings in terms of simple payback when evaluating equipment that still has useful remaining life. The cost to replace the equipment cannot be simply subtracted from the cost of the energy conservation measure. However, a complete life cycle cost analysis can be completed to identify the most economical approach.

Andy Jones, PE, is mechanical engineer/project manager at RMF Engineering. He can be reached at andy.jones@rmf.com.

Maintenance Savings May Help Justify HVAC Capital Investments

Once a bundle of projects has been identified, facility managers should also determine whether a reduction in maintenance expenses can legitimately be anticipated. Facility managers should determine if deferred capital renewal should be part of the analysis to justify large energy upgrades.

An example of additional maintenance savings that will lower the simple payback is a lighting project that changes out incandescent bulbs to CFL or LED bulbs. The typical lifespan of an incandescent light is approximately 1,200 hours, while a CFL has a life span of 8,000 to 10,000 hours and a LED light has a life span of 20,000 to 50,000 hours. The cost of the material and the time for repeatedly replacing the bulbs should be included in the analysis to identify the entire savings for the energy conservation measure.

Another maintenance savings example is replacing building pneumatic controls with a direct digital control (DDC) system. Pneumatic control systems use compressed air, which is typically generated by a compressor (or series of compressors, depending on the size of the system; some rare installations use nitrogen or other bottled gas). Typically the annual maintenance can be 40 man-hours for inspections and the scheduled monthly maintenance service required.

If this work is completed by a third party it is easily tracked and identified, but it is more difficult to identify the hours if this work is completed in house.

How Bundling Energy Efficiency Projects Helps Justify Large Capital Upgrades

A key step in justifying many large capital upgrades is to bundle them with other work that has a quick payback. There are a wide range of quick win strategies to bundle in with more complex endeavors. Low-cost or no-cost projects can be implemented by facility managers in conjunction with standard operations and maintenance procedures. For example, the facility manager can ensure that the outside air dampers for the air handling units are operational during peak cooling and heating conditions. If the dampers are not functioning properly and remain fully open during the winter months, the result would be an increase in energy use. The HVAC system would be trying to maintain the heating set point based on a lower mixed air temperature, due to the increased amount of colder outdoor air added to the warmer return air. If the dampers are functioning properly, the temperature rise would be much less and require significantly less energy.

Revisiting the applicable ventilation air requirements is another easy way to save energy. If a space previously used as a lab or a classroom is now an office, the amount of required outdoor air changes, i.e., the damper set points, could be altered. Also, changes made in space use often do not include HVAC system rebalancing. A space is often repurposed without any modifications to the HVAC system.

In a bundling strategy, the next step up from no- or very low-cost energy efficiency measures involves relatively small projects that may require an engineering design or additional evaluation. One example is the installation of variable frequency drives on motors. For example, a 20 horsepower pump operating 24 hours per day for a quarter of the year (91 days) with $0.08/kWh electrical cost will incur an electrical charge of $2,890 per year, assuming a motor efficiency of 90 percent.

The installation of a variable frequency drive will allow the pump to operate at decreased flow and pressure throughout the year. The flow will decrease at the same rate the motor speed decreases. The energy costs decrease as the cube of the flow (motor speed) decreases. If the installation of the variable frequency drive reduces the flow by 25 percent, then the resultant reduction in energy use is 58 percent. However, the reality is that approximately 50 percent energy savings will be obtained. The savings for this project is approximately $1,450 per year. Based upon RS Means, the average installed cost for a 20 horsepower pump is approximately $4,000 to $5,000 depending on location. The simple payback for this energy conservation measure is approximately 2.7 to 3.5 years.

All analyses of energy conservation project paybacks should of course be based on actual power rates paid by the facility. The impact on demand charges should also be considered.

Let’s Connect. Collaborate. And Partner Together! Let’s maximize your energy efficiency investments together: info@setpointsystems.com

Steps Beyond Simple Payback To Justify Large Energy Efficiency Investments

When top management relies solely on simple payback based on energy savings, it can be difficult to justify energy efficiency projects involving very large capital investments. Those projects may be uncovered by energy audits, which — with current state legislation and energy incentives — are becoming an increasingly popular means for identifying and implementing campus and building renewal projects. Energy audits help facility managers identify ways to reduce energy consumption by changing the operating schedule of HVAC or lighting devices. Audits can also help justify replacing inefficient, aging, or failing equipment within a building.

Simple payback calculation is sometimes used to determine if the change in schedule or replacement is required. The simple payback is typically calculated by dividing the annual energy savings for each project by the capital cost to replace or modify the piece of equipment. If there are any incentives or rebates, they are subtracted from the capital costs.

When top management relies solely on simple payback based on energy savings, it can be difficult to justify projects involving very large capital investments. The simple-payback approach does not present the whole picture of the value of the upgrade.

There are several ways to try to overcome the limitations of that approach. One is to bundle projects, so that work with very quick payback periods helps to balance upgrades with much longer paybacks. Another step to help show management the entire project value is to include other factors in the analysis, like maintenance savings and deferred capital (the cost to replace a unit in kind if the unit is beyond its useful life). These factors need to be calculated very carefully to ensure that they are realistic.

The importance of this broader approach can be seen from a project conducted under the Commonwealth of Massachusetts’ energy reduction program. The program aims to reduce energy consumption by 25 percent for all state-owned-and-operated facilities. The state used the simple payback method based only on energy savings (energy, rebates, and incentives) savings. The projects are expected to have a simple payback of 15 to 20 years or less to justify the investment.

A large state university evaluated under the program had identified a project with an energy savings of 21 percent and a simple payback of 19 years based upon energy consumption only. The university had to sell this project to its board and would have found it difficult with a simple payback of 19 years, but the university was also able to include the savings for deferred maintenance and deferred capital. The inclusion reduced the simple payback from 19 years to less than 9 years. (At the time of this writing, the contribution from utility company incentives and rebates for this campus was not included because a substantial amount of the design was not yet completed).

It’s important to note that there were more than 150 energy conservation measures identified in this project, with simple paybacks ranging from 6 months to more than 50 years. When all of these were considered under one umbrella, the overall project had a simple payback that was in the range of the total system requirement. Bundling helped to move forward projects with long payback periods; this is carefully programmed so that the overall project is still able to maintain an acceptable payback period.

Let’s Connect. Collaborate. And Partner Together! Let’s maximize your energy efficiency investments together: info@setpointsystems.com

Key Findings From Retrocommissioning A High-Performance Building

KLH coordinated multiple tests and reviewed the functional performance testing data and the building’s environmental trend data to find a solution to improve system performance and operating efficiency, and reduce energy costs. Through this research, KLH identified multiple issues, including a problem with the building pressure—the RTU exhaust fan was only enabled when the outside air damper was open above a minimum position and the building pressure was above the building pressure set-point.

The minimum outside air damper position was set to 10 percent on all RTUs and the power exhaust outside air minimum position was set to 20 percent. This set-point prevented the power exhaust from operating and maintaining an appropriate building pressure. After looking at the building pressure trending, KLH discovered that the building pressure would continually rise throughout the day, until approximately 5:00 p.m., when all of the doors opened as employees exited the building. Because the building envelope was secure and the doors remained closed, the building pressure would rise to the point where doors were difficult to close once opened.

To combat this problem, the outside-air minimum damper position set-point (for the power exhaust system) was lowered to 5 percent on RTU #4 in an effort to see if the power exhaust fan would engage and maintain building pressure. Once the set point was lowered to 5 percent, the rooftop unit immediately began to exhaust air. After this change, the BAS showed the building pressure decreased until the programmed building pressure set-point was attained.

In addition to these findings, the RCx study uncovered other opportunities, which KLH recommended to further improve the building’s energy efficiency. These projects include: carbon dioxide space monitoring and outside air ventilation control, a new control strategy for supply duct static reset, installing an enthalpy economizer control, and implementing a new supply air reset control strategy.

The success of the RCx project shows how to utilize RCx not only as a means of obtaining LEED certification points, but as a foundation for responsible energy management practices. According to Johanning, knowing that the mechanical systems and controls operating the buildings are working in sync—and efficiently—creates peace-of-mind, and RCx is the vehicle to deliver those results. Not only did the Springfield RCx project exceed Johanning’s expectations, it also expedited the funding approval process for some of the recommended corrective actions to further enhance efficiency.

The Springfield RCx project was so successful that the business is planning to conduct RCx studies in selected facilities throughout its commercial office portfolio to further drive down operating costs. RCx is proven to be a smart choice for facility managers and building owners who want to streamline their building’s performance and operations. Doing so can further improve building efficiency, save monthly costs, and ensure happier employees with more comfortable working conditions.

Jerry Schmits is Director of Energy Solutions at Kohrs Lonnemann Heil Engineers. You can reach him at jschmits@klhengrs.com.

Retrocommissioning Improves Energy Efficiency In High-Performing Buildings

LEED certification and Energy Star benchmarking continue to grow in popularity for existing buildings as pressures mount to control operating expenses. As a result, energy efficiency is now mainstream, and managing a building’s energy performance is standard procedure among an ever-growing number of facility managers.

Energy Manager Patrick Johanning is one of them. Johanning works for an international commercial real-estate services corporation, where he manages energy cost and consumption for a Fortune 500 financial services company. Acting on a hunch that he could improve energy efficiency and reduce operating costs among his top-performing facilities, Johanning looked into retro-commissioning (RCx). The result was an RCx project in Springfield, Ill. — performed on a building that was LEED Gold certified with an 89 Energy Star score — which managed to produce a 10.4 percent energy savings on its HVAC system.

Multiple options existed for reducing the energy-related expenses, including energy audits and re-lamp projects. But while the benefits of these activities are well documented, the state of efficiency that existed between the facility’s mechanical and operating systems, and the control systems that function on the front-end, was not documented. While the RCx process is intended to restore a building’s equipment and mechanical systems back to their original operational design, functional performance testing can also improve energy efficiency. In short, if Johanning could show favorable RCx results in a high-performing building, he could find support for an RCx program across the entire commercial office portfolio. The first challenge was to both prove his hypothesis and get the project funded.

The funding arrived in the form of an RCx study rebate provided by City Water Light and Power (CWLP), the power utility company serving the building’s area. Johanning then hired Kohrs Lonnemann Heil Engineers (KLH), an engineering firm with experience in energy solutions and the RCx process, to help restore the building’s systems back to their optimal operational state while focusing on potential energy saving opportunities. The following details how KLH worked with Johanning to reach RCx success.
Beyond the low-hanging fruit

A review of the current facility requirements confirmed that there had been no material changes in the building zoning or use of the facility from its original design and construction.  Based on this information, the scope of the project was designed to focus on domestic hot water, snow melt, lighting, and HVAC. There were no blatant, major equipment or operational issues; preventative maintenance practices were in place; and the building was in exceptional physical condition. However facility staff interviews uncovered some issues related to fluctuations in the building pressure.

Functional performance testing of the HVAC system and testing of the BAS revealed discrepancies in the airflow throughout several of the VAV boxes. In addition, data from the BAS showed a steady increase throughout the day in the building pressure, and that the exhaust fans were not properly maintaining appropriate pressure levels. But despite these pressure levels, carbon dioxide levels only reached 75 percent of the maximum acceptable levels for indoor air quality—well within the ASHRAE minimum standards. The absence of obvious energy conservation measures—the low-hanging fruit—meant that the success of the RCx project would be an even greater challenge.