4 FM quick reads on Energy Efficiency
1. Measuring Exterior Energy Efficiency
Today's tip is about the important measures facility managers should be aware of when trying to quantify the quality and energy efficiency of exterior building elements.
For roofs, the two main measures are solar reflectance and infrared emittance. Solar reflectance measures a surface's ability to reflect infrared, visible and UV light. Generally, the higher the solar reflectance, the more energy efficient the roof will be. Infrared emittance measures a surface's ability to re-emit any energy absorbed back into the atmosphere. A so-called "cool roof" generally has an emittance value higher than .90 and a reflectance value of .65 or higher. Finally, solar reflectance index, or SRI, is a combination of the two via a standard calculation. SRI is the new standard used in LEED.
For windows and skylights assemblies, U-factor measures heat loss. The lower the number, the better the performance. Solar Heat Gain Coefficient measures how well a product limits radiant heat gain from sunlight. Visible Transmittance measures how much light, but not heat comes through. The higher the number, the more light is transmitted. Finally, Condensation Resistance indicates a product's ability to resist the formation of condensation on interior surfaces. The higher the rating, the better.
For wall assemblies, the best measure for efficiency is R-value - or the thermal flow resistance. The higher the R-value, the better the insulating effectiveness. When calculating the R-value of a wall assembly, the R-values of the wall, insulation and any other layers are totaled to arrive at the R-value of the total assembly.
2. Facility Dashboards Show Energy Efficiency
Today's tip is about how you can use facility dashboards to show energy efficiency and get your much-deserved recognition from building occupants, tenants, visitors and, most importantly, the C-suite, for energy efficiency projects.
Many companies, K-12 schools, colleges and universities, and developers in multitenant facilities are now using an in-lobby dashboard that is hooked directly into the facility's building automation or metering system to show real-time energy, water and carbon emissions data. The dashboard also can show energy saved by particular energy efficiency technologies like lighting, as well as real-time data of energy being produced by onsite renewable energy strategies like wind or solar. Greenhouse gas emissions, both in terms of real-time emissions, as well as emissions avoided by particular strategies in the building can also be displayed. All of this is done on a touch screen graphical interface that is simple and fun to navigate.
Additionally, this can all be put on the Web, so remote users (and journalists!) can see what exactly is going on at a building at any given time.
Experts in the industry always say how important it is for facility executives to communicate with occupants or tenants about green building and energy efficiency initiatives. Not only do these dashboards provide an automated and graphically hip way to explain energy efficiency initiatives, they also are a great educational tool to teach occupants and tenants about energy and water efficiency.
3. Fault Detection And Diagnostics Software Has Potential To Save Energy
Today's tip from Building Operating Management comes from Jim Sinopoli of Smart Buildings LLC: Fault detection and diagnostics software has the potential to save energy from HVAC systems.
There are now several types of software analytics tools and applications to help analyze building data. But the one with the best-verified results and cost effectiveness is known as fault detection and diagnostics.
Fault detection and diagnostics, like other analytic software tools related to building systems, primarily supports technicians and engineers in the field who are dealing with both everyday operational matters and details of building operations as well as broader issues of complicated systems, advanced technology and higher expectations for building performance. The fault detection and diagnostics analytic tools provide insights into building systems that help reduce energy consumption, improve building performance and lower costs.
Fault detection and diagnostics does just what its name implies: It finds problems within HVAC systems and offers guidance about solving those problems.
It's a challenge to keep a significant, energy consuming system such as HVAC running at optimal performance. Many times failures or sub-optimal performance go unnoticed for long periods of time. Case studies from companies selling fault detection and diagnostics software services can show energy savings in the 10 percent to 15 percent range; the tools are said to have the capability to correctly identify faults and spell out the primary response 95 percent of the time.
Software based on fault detection and diagnostics is really a new class of tool for facility managers, providing them nearly real-time analysis and diagnostics of their HVAC systems and adding some "smarts" to a smart building. It's not difficult to imagine similar tools for other building systems, with the potential for enhanced intelligence built into tools for facility management.
This has been a Building Operating Management Tip of the Day. Thanks for listening.
4. Check Efficiency Of Daily Operations
Today's tip is to look at the day-to-day operations of your facility to find greater energy efficiency. Changes such as improving BAS/EMS programming and aligning operating schedules with need can ensure their buildings are being run in the most efficient manner possible.
Allan Skodowski, senior vice president, LEED and sustainability, Transwestern, says that when Transwestern audited the poor energy use of a suburban Milwaukee school, it didn't take long to find a big problem: more than 250 horsepower worth of fans running after hours due to incorrect programming. "That change alone has taken them from a (Energy Star rating of) 55 to an 83," Skodowski says. "They're going to save about $40,000 this year in energy."
Another good starting point is looking at the use of basic building machinery before trying to dig deep into set points or strict lighting schedules, says Rafael Mendez, building manager, General Services Administration. Mendez's building, the Wilkie D. Ferguson, Jr., U.S. Courthouse in Miami, has cut more than $1 million in energy costs.
"One of the things I noticed first was we have three escalators from the lobby to the fifth floor," Mendez says. "We had them operating most of the day and they weren't heavily used." The escalator schedule has been revised to run from 7 a.m. to 10 a.m. on Mondays, Tuesdays and Wednesdays.
Keeping a close eye on usage by examining utility bills can also help spot problems. Brenna Walraven, managing director, USAA Real Estate Co., experienced this when one of USAA's buildings was using a baffling amount of energy, yet the energy management system showed nothing wrong.
"What was happening is there were several faulty relays, so the EMS would send out 'turned off' signals. In actuality the building was running nonstop," she says. "It literally cost about a couple hundred bucks to replace those and saved us about 10 percent." "The building systems will be dumbed down to the level of the least-trained person who works on those systems," says Wayne Robertson, president, Energy Ace. "You need to accompany that building automation system with training."
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