Recent trends have been growing more favorable toward the use of energy-efficient lighting, a driving factor in an increasing number of commercial and industrial retrofits.
By Carol Brzozowski
Market research from SBI Energy indicates international concern over global warming—and the role of incandescent lighting in energy consumption—is one of the driving factors.
Government and utility rebates provide an incentive for lighting retrofits, especially for facility managers who walk the tightrope between addressing escalating energy bills against the backdrop of tightened budgets. Such incentives speed up the return on investment (ROI) of funds needed to finance retrofits.
A rising star in the post-incandescent world is the light-emitting diode (LED) light, with induction lighting capturing increasing interest. Controls play a key role in reducing the consumption levels of lighting, while enabling it to adequately respond to facility needs. Computer technology offers even a greater ability to respond to demand without wasting resources. Emerging technologies that will continue to influence lighting installations and retrofits include solid-state lighting, daylighting, and smart building controls, according to SBI Energy.
The Continental Automated Building Association reports properly networked buildings can cut energy bills by up to 70%, with asset values increased by multiples of two to 30 times the initial investment.
Also emerging is quantum dot technology, nanotechnology-scaled bits of semiconductors that can be scaled to create colors of any hue, according to SBI Energy.
Target: Lighting Strategies
In Houston, TX, MedSafe’s primary distribution center serves as a hub from which the supplier of occupational, health, and safety equipment services a national clientele. Its strategic location enables the company to provide disaster relief supplies in the aftermath of a hurricane or tropical Gulf Coast storm. However, its location is also a liability, placing it squarely in the path of severe weather events.
When the company moved to a larger distribution facility last July, management decided a new lighting system was needed, thus 141 Dialight DuroSite Series LED High Bay interior fixtures and 18 exterior area lights were installed. The installation features an illuminance level of 24 foot-candles with a mounting height of 28 feet and high-bay spacing of 25 feet by 10 feet. As a result, the company has increased illumination while maintaining energy costs at the same level—its new 125,000-square-foot facility built to accommodate business growth is four times the square footage of its former building, yet the cost to light it is the same.
“Our utility bills have continuously escalated, specifically in the preceding summer when there was a huge spike in energy costs,” says Burk Shaw, Medsafe’s president. “I wanted to mitigate that as much as possible with better technology.”
Now the company has lower bills, due to lower consumption and negotiating more favorable rates with the utilities.
“We’re extremely happy with the lights’ performance, being instant on and off,” says Shaw. “It’s a much cleaner look and a much whiter light for us in the warehouse. I put some different LED security lights outside that are also whiter.”
Another key benefit is the system’s ability to instantly restrike after a power outage, eliminating downtime. That is important for the company, which provides an aggressive disaster preparedness program that must kick into high gear immediately after a hurricane hits. At its previous facility, power outages could last as long as 15 minutes while the 400-W metal halide and fluorescent lights entered a restrike mode.
Productivity has also improved. The former facility was 13 years old and had dim yellow lighting. It created visibility issues for workers trying to read bin location information. (The company has since moved to an electronic bar code reading system, but workers still appreciate the greater visibility.)
“Primarily, I wanted to have that instant on/off that is available with LED technology,” says Shaw. “Secondly, I wanted to address the electric consumption, and third, I wanted a better-looking appearance for the facility so that we eliminated some of the fill rate issues or errors when we were pulling orders.”
It was Dialight’s ROI calculations (the expected ROI is 3.5 years) that helped Shaw choose the correct products for the retrofit. A Dialight salesperson met with MedSafe’s engineer to ascertain lighting needs and ensure proper lighting products were chosen.
“LED lights are much more expensive than traditional technology, so obviously I had to have a numbers case behind what I was doing,” says Shaw. “Dialight was the most proactive in assisting me with tools. They were the most interested in my project, coming out to show me different versions of the technology.
“They kept me up to date on newer technology,” he adds. “It’s not broad lighting, but high-bay directional light directed to specific aisles, which is where we needed it. That technology was extremely intriguing; their warranty was better.”
Shaw advises other facility managers to reach out to lighting manufacturers to gather information.
“They’re on the forefront of technology, and I think it’s improving daily,” he says. “Everything is changing so quickly. We have to have somebody else to be the expert in areas that we don’t do anything at all with.”
Michael Schratz, Dialight’s marketing director, says Dialight specializes in LED high-bay fixtures.
Dialight works through an electrical distributor network that provides the retrofitting services. The retrofitting process begins when a facility brings in an expert to ascertain the exact amount of foot-candles required to provide the amount of needed light.
“Once they have an idea of a foot-candle requirement on the ground, we do in-house lighting layouts using state-of-the-art software where we’re able to tell them exactly how many fixtures they need,” says Schratz. “Normally, it’s a one-for-one replacement. We’re able to show them we’re meeting or exceeding the foot-candle requirements with our LED fixtures.”
After a facility chooses the fixtures, an electrician installs them using existing conduit and wiring.
“There’s no additional infrastructure needed to replace the LED fixtures, but it is a complete fixture replacement,” says Schratz.
Facilities also need to consider recycling old fixtures and bulbs since they typically contain mercury, Schratz points out. Dialight has a partnership with Veolia Environmental Services, which recycles the old products at a cost.
At the New England branch of CB Richard Ellis, a major full-service commercial real estate firm, chief engineer Alex Sutelman was seeking ways to save energy.
“In my opinion, lighting is the easiest one to get through ownership approval because usually the cost is not tremendous and the payback is usually not that extensive,” he says.
Sutelman met with various lighting company representatives and found Lutron to be the best match for his company’s needs. One of the compelling factors was a one-year payback as well as manufacturer support.
In-house mechanics and building engineers installed the 210 Lutron Stairwell Fixtures— including a ballast, switch, and faceplate—over six weekends and after office hours under the deadline allowed by the utility, NSTAR, which is Massachusetts’ largest, investor-owned electric and gas utility. The utility approved the project and the office qualified for a rebate check.
Sutelman says he also chose Lutron because, “no one else has that approach in the dimming ballast, and I believe no one would offer this kind of energy savings with their product. I believe it will extend the lamp life substantially.”
Sutelman advises other facility managers considering lighting retrofits to ensure there is no degradation in the light quality and output.
“Make sure it is not a substantial capital investment as well,” he says. “There are a lot of areas to jump through. Get the most efficient product with the best payback.”
Wireless control technologies that were once available in high-end residential applications are now available in the commercial sector and have become one of Lutron’s fastest-growing applications and platforms in the company, says Tom Myers, Lutron’s director of Commercial Real Estate Solutions.
The Dialight lighting system installed at MedSafe’s new facility increased illumination while still maintaining energy costs at the same level.
The company’s new line of commercial grade wireless controls enable an end user to add occupancy sensing or daylighting controls to an existing facility without the need to change existing wiring. The wireless technology conquers the largest obstacle that building owners and end users have faced with lighting retrofits—labor costs to add controls to an existing building, says Myers.
“The price of the product wasn’t prohibitive, but the price to install technology by having to change or add wiring or conduit was cost-prohibitive with a lot of these applications,” he notes.
When a facility is ready for a lighting retrofit, Lutron representatives visit the facility to determine if it shows promise and opportunity, Myers says. Next, both Lutron and the end user choose a contractor.
“Contractors are key in helping evaluate installation requirements and costs,” says Myers. “We use our expertise in identifying what applications and technologies could be retrofitted and the contractors’ expertise in what the installation will require and cost. We then provide a combined turnkey cost proposal to the end user with a summary of the technology, its applications, installation costs, and the ROI.”
Lutron assists facility managers in understanding current energy and maintenance costs of their lighting system as well as future energy and maintenance costs, and applies that to the total turnkey cost estimates for the retrofit solution, Myers says.
AMB Property Corporation owns, operates, and develops industrial real estate at major hub and gateway distribution markets in the Americas, Europe, and Asia. The company’s sustainability program focuses on improving energy performance of its property portfolio, green building development, and renewable energy, such as rooftop solar projects. AMB identified lighting as one of its largest sources of energy consumption and began to target that in 2005.
“In a typical warehouse, traditional lighting is responsible for as much as two-thirds of total energy use,” says Tom Spanley, the company’s senior project manager. “Lighting retrofits are the single fastest and most effective way we have found to reduce whole-building energy consumption, often by as much as one-third or more. This not only saves our tenants a considerable amount of money, it also improves lighting quality and promotes a better working environment while reducing environmental impacts.”
The company’s first test case came six years ago when a tenant in one of its warehouse buildings requested a lighting upgrade to six lamp T-8 fluorescent fixtures as part of renewing their lease.
“AMB worked with Cooper Lighting and the tenant to successfully complete the lighting upgrade project in the weeks that followed,” says Spanley. “Based on the success of that project and the cost savings achieved, AMB began to look for other opportunities to work with tenants to upgrade their lighting.”
Cooper Lighting assists in evaluating opportunities, analyzing existing and proposed energy consumption, and making product recommendations, with a national network of installation partners available to implement the project. The first step in beginning a retrofit process is to identify the opportunity, Hall points out.
Since that time, AMB has gone on to implement lighting improvements in 75% of its southern California property portfolio, which encompasses 22.9 million square feet and more than 175 buildings.
“In 2010 alone, AMB upgraded eight million square feet in southern California. AMB continues to implement lighting upgrade projects throughout California and nearly all of its 15 US property markets,” notes Spanley.
In all, AMB has upgraded more than 38 million square feet of properties across North America. Over the next five years, these investments are anticipated to produce an estimated $35 million in energy savings for its customers and reduce carbon emissions by 150,000 metric tons.
As part of the retrofit effort, an energy audit was conducted to establish the energy usage for nearly all projects.
“This allowed us to quantify the energy and dollar savings. The audits are also used to ensure we are able to obtain utility rebates for high-efficiency lighting,” says Spanley.
While each project is different, the ROI from energy savings is often less than two years in southern California, where electricity costs are high and rebates from the utility support energy saving upgrades, says Spanley.
“In most cases, the energy savings benefits the tenants in our buildings rather than benefitting AMB directly,” he adds. “These projects also benefit AMB. They help us retain tenants by reducing building operating costs and modernizing the lighting of our properties.”
AMB chose Cooper because the company provided an AMB-specific model number to the products to ensure consistent product specification and ease of procurement, says Spanley.
“Product support and customer service was a key to the decision to work with Cooper,” he says. “AMB seeks to establish mutually beneficial long term relationships with suppliers.”
Additionally, Cooper was able to negotiate the best pricing structure in the industry and meet variable demand due to the changing volume of projects active at any given time, Spanley says.
Also, “Cooper has a global presence and has the capability to respond to our needs in nearly every market where we own properties,” he adds.
When Halstead International—a manufacturer of flooring and countertops—was seeking energy-efficient lighting for its new call center, specifying engineer Andy Chen, of the 20/10 Engineering Group, recommended Waldmann’s Minela task lighting.
“This is designed to be a LEED [Leadership in Energy and Environmental Design] building, and they’re aiming for a LEED platinum rating,” says Chen. “My role is specifying anything that’s as energy-efficient as possible, and lighting plays a major role in that.”
The Minela task lighting, a 2010 Red Dot Design winner, has a 5-W high-power multichip LED strip design. Lighting system controls can earn one credit toward certification, Chen points out.
“Ninety percent of the occupants need to have individual controls,” he says. “What we have here are two open offices with multiple work stations. In order to achieve that credit requirement, we need to provide individual controls for the individual needs, so that’s why we specify individual task lights at each work station.”
The project, which entailed 25 fixtures, was completed in summer 2010. Chen says he chose Waldmann Lighting because it offered energy-efficient LED lighting that include dimming capabilities and automatically shut off after 14 hours.
Chen’s recommendation for other facilities contemplating LEED certification through lighting is to choose task lighting.
“It plays an important part in meeting that requirement, especially if you have open office spaces with multiple work stations,” he says. “You’re not going to achieve that credit with regular light switches that control lighting in an entire space. You need individual task lighting to center on individual needs. Going with the LED task lighting saves the owner money on lamp replacement as compared to regular halogen or compact fluorescent options.”
Task lighting comprises most of Waldmann Lighting’s applications, notes Lou Calvo, the company’s director of sales and marketing.
“There are primarily two lighting technologies we utilize—LED and fluorescent,” says Calvo. “Florescent still has a lot to offer in terms of reducing energy usage in modern buildings.”
Customers look to Waldmann Lighting to reduce the amount of energy being used on task lights, which are typically incandescent desk lamps.
“We’re retrofitting a lot of those 60- to 75-watt units with eight-watt LED units,” says Calvo. “We’re able to reduce the energy consumption by about 10 times going to an LED solution versus the traditional incandescent solution used on the desk before. In addition to the 90% energy savings in that particular scenario, we also reduce a tremendous amount of heat that’s being generated by that incandescent light.”
About 90% of the energy that an incandescent uses generates heat rather than light, says Calvo.
“With LED, even though there is a minimal amount of heat, it’s reversed—90% of that energy is being utilized to produce light instead of heat,” he says.
Another key factor is maintenance, Calvo says.
“A lot of folks looking to retrofit want to get into technology that doesn’t require the level of maintenance that some of the newer products have,” he says. “What we’re seeing now are lights that are scheduled to work anywhere from 10 to 15 years in continuous operation.”
Incandescent lamps may be replaced every 1,000 to 2,000 hours, which can mean six months to a year before they will need to be replaced, Calvo says. Savings are being achieved from not having to procure lamps, not having to dispose of lamps, and then generally the reduction in heat from the individual work stations in getting away from much hotter sources that you would traditionally use for task lighting,” he adds.
Waldmann Lighting does not perform energy analyses.
“The end user will want the building to be tested by an independent testing lab that specializes in commissioning, which essentially demonstrates that the savings that the manufacturers are claiming are actually accurate,” says Calvo. “Typically, they don’t like manufacturers doing their own audits because there could be a conflict in terms of what’s actually being accomplished.
“A lot of times what happens is we go into an application as part of a package of lights so they might want to use us for the retrofitting of the task lighting, another company for the retrofitting of the high bays in the factory, and another company for the corridors. Typically up to five companies are working together to retrofit a location.”
The critical factor is looking for areas where there is currently energy waste, Calvo points out.
“One of the key things companies need to keep in mind is that just lowering the light levels is not exactly saving energy,” he says. “It’s not saving energy if the employees can’t see what they’re doing and have to augment the lighting you provide.”
Much is contingent upon what applications or tasks are taking place in the given areas being lit. For example, corridors are an area that can typically benefit from lighting efficiency efforts.
“Corridors typically are completely lit, but very seldom used,” says Calvo. “One of the first things I would recommend is occupancy sensors in the corridors. If there is no one in the corridors, you may be able to have every other light on or every third light on, and then if people are actively moving up and down the corridors, the sensors would detect their presence and the whole corridor would be lit.”
Another factor to consider is the open office floor plan.
“There are a lot of situations—especially now—when only a portion of that open floor plan is being occupied, yet you’re lighting the entire floor regardless of whether the folks are in the cubicles,” says Calvo. “The ability to use controls there to only have the lights on where there are people actually working can save a tremendous amount of light.”
Lighting retrofits for energy efficiency isn’t necessarily about replacing equipment, but has more to do with control of the equipment already present, Calvo says.
“A lot of equipment for buildings that have been constructed over the last 10 or 15 years do have very efficient lighting, but the problem is the lights are burning all day long with no controls whatsoever,” he says.
“Even though it’s an efficient florescent source, the reliance on human intervention and the on and off functions are what wastes the energy, not necessarily the light fixture. So, a lot of times, it’s the operation and usage of the products that can benefit without even having to replace any light fixtures.”
Important factors that need to be considered is what equipment is currently present in a building, where are the opportunities to save energy, what light levels are required for the individual areas relative to the tasks occupants are doing, and where are there opportunities to be able to light spaces with natural daylight rather than artificial light, Calvo says.
“Those are ongoing and can be closely monitored and measured over a given period of time,” he says. “A typical ROI that folks would look for in a renovation application would be somewhere in a five-year time frame. Some of the benefits would be a reduction in maintenance, a significant reduction in procurement in terms of replacement bulbs, replacement ballasts, and improvement in terms of light levels.
“Just because you’re renovating doesn’t necessarily mean the quality of light has to go down; it’s the quantity of light that would have to be reduced, but a lot of times the newer products will actually improve the light levels.”
Calvo suggests that facility owners look for a consistency in products throughout the building so as to avoid an inventory of different lamps, ballasts, and equipment.
“If you can standardize on a few pieces of equipment, it certainly is going to reduce maintenance costs as well as the ability to keep the place functioning without having to force different styles of lamps that aren’t readily available,” he says.
|Photo: Blue Sky Lighting Products
Blue Sky Lighting Products suggested MTU retrofit its manufacturing operation with EverLast induction lights.
|Photo: Blue Sky Lighting Products
When Wearguard-Crest, a division of Aramark, decided to replace all of the lighting fixtures throughout the 280,000 square feet of office, manufacturing, and retail space at its headquarters in Norwell, MA, the aim was to do so in such a way that the cost of the project would pay for itself in energy savings.
The company worked with J & R Industrial Wiring in Plymouth, MA, to come up with a solution that would provide the best ROI. J & R Industrial Wiring selected Demand Control Lighting (DCL) from Universal Lighting Technologies (ULT) because it could reduce power to lighting ballasts by as much as 50% without the need to install expensive wiring. The DCL Control System can be operated manually or automated. The control system communicates with the ballasts at the circuit level. Each lighting circuit is controlled individually for zone programming.
For the retrofit, J & R Industrial Wiring worked with ULT to design an automated lighting control program to optimize energy savings throughout the facility. Lighting fixtures in the office, lobby, and hallway areas were divided into eight zones with photocells for daylight harvesting between 7 a.m. and 6 p.m. Scheduling software would control the entire facility so lights would automatically adjust to 50% power at 6 p.m. for cleaning crews, then 0% at 11 p.m.
The retrofit began in September 2008 when J & R Industrial Wiring replaced the facility’s outdated lighting equipment with ULT’s DEMANDflex ballasts. The high-efficiency T8 ballasts can be individually “tuned” by the installer to the appropriate ballast factor to ensure the right amount of light for the application to eliminate overlighting and energy waste—at Wearguard, they were tuned to 10% to 20% below full power even before the DCL Control System was installed, beginning in January 2009.
The projected energy savings of 539,531 kWh represented a 45% power reduction being consumed by the facility’s lighting fixtures. The project derived incentives from the local electric utility, National Grid.
Officials from Wearguard-Crest and J & R Industrial Lighting have noted a significant power consumption reduction through daylight harvesting. But that’s not the end of the story for Wearguard-Crest’s facility. It will continue to benefit from newer technologies that J & R Industrial Lighting is incorporating into jobs it’s now doing, including control products, the ability to be smart grid-enabled, greater automation, and the use of Web browsers in lighting systems, says Jim Killion, a project engineer for J & R Industrial Lighting.
ULT’s DCL system, including DEMANDflex ballasts, is aimed specifically at energy efficiency with low initial costs and optimal ROI, says Randy Dollar, vice president of Systems Market Development for the company.
Whether an end user chooses ULT to do an energy analysis or outsource it to someone else, key factors in the analysis include number of light fixtures and types, lamp types, number of lamps per fixture, line voltage, type of ballasts currently used, utility billing information (kilowatt-hour rate, peak kilowatt demand charge, off-peak kilowatt demand charge), number of lighting circuits, any location-specific information such as desired time-of-day scheduling, demand response programs, and other measures that can be used for energy efficiency measures, says Dollar.
A contractor uses that information as a basis for changing existing ballasts with DEMANDflex ballasts. If controls are part of the retrofit, they are installed in the electrical closet near the existing lighting panel board.
“Once installed, the controls are then commissioned by the contractor or a systems integrator,” says Dollar. “At this point, the DCL system can provide information back to a building automation system for data to be used in a graphical user interface, alert systems, or any other features the end user may be utilizing or have a desire to implement.”
Dollar points out that a typical ROI is less than two years, and there are many utility incentives for energy-efficient lighting.
“Most utilities have performance-based rebates that reward energy savings on a ‘before and after’ basis,” he says. “Since DCL can provide tremendous energy savings, significant rebates can be obtained that reduce the initial cost to the end user. Many utilities offer a demand response program as well.”
The demand response program pays end users money to shed electrical load during times of peak demand when the utility is reaching or exceeding peak capacity.
|Photo: Blue Sky Lighting Products
With an open floor plan, the ability to light only the area
currently occupied can help save money and energy.
Target: Green Replacements
When MTU Detroit Diesel purchased an existing brownfield facility in which to locate its off highway manufacturing operation in Aiken County, SC, one of the first orders of business was to replace a large quantity of existing metal halide fixtures.
“We’re known as a green company,” says Rob Rehnlund, senior manager of facilities engineering for MTU Detroit Diesel, a subsidiary of the Germany-based Tognum Group. “One of our first steps with this building was to do something proactive to reduce energy costs.
“The existing light fixtures were over 14 years old and ballasts were bad,” notes Rehnlund. “Those particular lights lose about 30% of their efficiency within the first year, so we weren’t actually getting the lumens or lux out of the fixtures. We were paying higher energy costs for very poor lighting. The ballasts were humming—they were all bad.”
|Photo: Courtesy of Graybar
High-efficiency ballasts can be “individually tuned” by the
MTU’s first solution was to try to retrofit with LED lighting.
“We had said we would sign a contract for the LEDs, but we had to make sure they performed well,” says Rehnlund. “No one had really put them in a production environment in a plant. We tried them, and they did not perform well at all. They were flickering, and the light we were getting out of them was not what we were told we were going to get.
“Our workforce didn’t care for them,” he adds. “It wasn’t natural, and it wasn’t bright enough for us.”
Rehnlund enlisted the assistance of Blue Sky Lighting Products, which suggested MTU retrofit its manufacturing operation with EverLast induction lights. Blue Sky was the only company that had suggested induction lighting, Rehnlund notes.
The lighting technology is akin to a fluorescent lamp, but without electrodes. As such, the lamp relies on the gas discharge and electromagnetic induction to produce light with an anticipated life span of 100,000 hours. “We were told this technology is not new, but we had not been aware of this product or seen them in use,” says Rehnlund.
The lights proved less expensive than LEDs—and more expensive than T5s—but Rehnlund liked the 10-year warranty on the light fixture, including the ballast and bulb. Rehnlund tried them out on an assembly line. The operators favored the lights. The induction lights were also less labor-intensive to install in the plant, which has a complicated hoist system, Rehnlund says.
“It’s a natural light,” notes Rehnlund. “When they walk in and out of the plant, they aren’t squinting like they were with the older-style lights. For us, it was all about trying to get that natural light, which is good for the operators and ergonomics. It is important to us to provide the best quality working environment for the plant worker by getting the best light for them.”
The existing 400-W fixtures, which at 277 V were pulling 1.87 amps, were replaced with 200-W induction fixtures, which at 277 V pull only 0.77 amps. MTU has cut its lighting bill in half as a result of the retrofit. Additionally, MTU was able to take advantage of tax credits by installing the new lighting.
“The tax credits were pretty significant, and we did want to take advantage of them,” says Rehnlund. “Otherwise, we wouldn’t be able to afford it. They’re not cheap lights, but with the tax incentives, ease of installation, and low-maintenance costs made it more doable for us.”
MTU will realize a one-and-a-half-year payback on the retrofit, he says.
Target: Roadside Lights
While most energy efficiency retrofitting projects take place inside of a facility, or with lighting attached to the outside of the building, others are onsite at construction sites, such as road projects. Because Patten Industries works with a variety of pavement contractors responsible for completing roadwork repair and maintenance at night, keeping workers and motorists safe is critical.
The company was seeking lighting solutions to the challenge of conventional 4,000-W trailer-mounted light towers that were initially used at the job site, but emitted excessive glare and created shadows, negatively affecting oncoming traffic and making it difficult for workers to see well. Additionally, the large and cumbersome conventional light towers were difficult to move to each location as the repairs progressed.
Patten Industries tried a non-glare balloon light that was easier to transport, but not bright enough to conduct nighttime road repairs, which again created a hazardous environment for motorists and workers. As often as four times each night, the non-glare balloon lights required replacement of its light-duty halogen bulb, which could not withstand vibration, causing construction and repairs to halt and creating unnecessary downtime.
Patten Industries then chose Multiquip GloBug, a glare-free, 360-degree balloon light. It was more lightweight and rugged than the previous lighting system and offered an output of up to 110,000 lumens for greater illumination. Multiquip’s GloBug lighting systems use metal halide light bulbs for non-glare light and shadow reduction. They also are able to withstand vibration and rugged job site conditions.
Patten Industries derived efficiencies by attaching the GloBugs to its pavers and other mobile equipment, eliminating the need to reposition the light tower as the machines advanced.
“The product increases our customer’s productivity, and makes the work environment safer for both the public and for the employees, ” notes Bill Borre, operations manager for Patten Industries.
Author's bio: Carol Brzozowski writes on the topics of technology and industry.