Dan Rafter 2015-11-11 14:10:06
Chuck O’Donnell says it’s simple: the boilers that provide heat and hot water in factories, distribution centers, and warehouses across the United States consume less energy today because customers have long demanded more efficient versions as they look to slash their yearly expenses. Boiler manufacturers responded, continuously boosting the efficiency levels of their boilers to meet this demand. It’s a trend that continues today, says O’Donnell, director of marketing for Laars Heating Systems, a subsidiary of Bradford White and a manufacturer of boilers, including those used by industrial customers. He explains that the movement toward efficient boilers started in the North American market in the early 2000s and has been accelerating ever since. Boilers before this time generally featured annual fuel utilization efficiency—better known as AFUE—of about 80%, he adds. These boilers generally converted 80% of the fossil fuel energy that they consumed into heat. The other 20% of the fossil fuel energy they consumed each year was lost. That has changed. Today, manufacturers can provide industrial clients with boilers that boast AFUE ratings from 90 to 96%, O’Donnell says. In such high-efficiency boilers, up to 96% of the fossil fuel energy consumed annually is actually used for heat and not wasted. “End users absolutely want the higher-efficiency boilers today,” he says. “That has become such an important factor for all users, including industrial users.” Saving Money The reason is fairly obvious: Industrial users today are focused on their bottom lines. That is nothing new. But with a national economy that is still sluggish despite improvements, industrial users are looking even more closely at ways to reduce their annual expenses. Cutting labor costs can be painful, often requiring several rounds of firings or layoffs. At the same time, many industrial users have already squeezed as many efficiency gains out of their workers as humanly possible, and can no longer ask their employees to do more work in less time. And charging more for their products? That could chase away their potential customers. When it’s time to reduce annual operating costs, industrial users often find that increasing the efficiency levels of their power, heating, and cooling systems is the least painful strategy. That’s where more efficient boilers come in. By wasting a lower amount of energy each year, these newer boilers can dramatically reduce energy bills. This is especially true for industrial users who operate large, energy-intensive spaces. “As fuel costs have gone up, people are looking to save money all around,” says O’Donnell. “Heating a large area can be expensive. Even in large buildings in warm climates, end users still have to heat their water. That can require a large load, too. The heating side and the actual hot water side can add up to large expenses. By reducing these expenses, end users can save a lot of money each year.” At the same time, federal, state, and municipal governmental agencies are offering all users valuable incentives for reducing the amount of energy they consume each year. By investing in higher-efficiency boilers, industrial users might qualify for financial incentives. “The incentives help people justify the initial costs of putting in the higher-efficiency units,” says O’Donnell. “Getting those rebates can make those costs feel like a lot less of a burden.” Maintenance Matters Boilers, even high-efficiency ones, won’t generate the lowest possible energy bills, though, if their end users don’t properly maintain them. Fortunately, maintenance requires little work on the part of end users. Gerardo Lara, senior sales engineer at Rentech Boiler Systems, says that industrial users can help keep their boilers efficient by performing simple routine maintenance. Mostly, this means keeping their boilers clean. But Lara also recommends that users hire a combustion specialist once every year to make sure that the units’ combustion controls are operating according to specifications. Paul Rohrs, design and application specialist with Lochinvar LLC, a manufacturer of high-efficiency boilers and water heaters, agrees that maintenance is relatively simple. The first key is to make sure that boilers and boiler systems are installed properly. The company that installs the equipment should handle this task, Rohrs says. They’ll do this in part by using a combustion analyzer to measure the amount of carbon dioxide that boilers emit while operating on high fire. Users should also hire a boiler specialist to service the heat exchangers of their boilers on an annual basis, he says. Tweaks Matter Mass-produced boilers are more efficient today. But customized boilers can reach even higher levels of efficiency. As an example, look at the customized boilers that Rentech designs. Lara says that Rentech will design custom boilers that boast far higher efficiency levels than do mass-market versions. “It has to be a very energy conscious consumer,” he says. “To get such a high-efficiency boiler, you have to invest quite a bit in capital equipment. We are mindful of what is out there in the market, the competition. Not everyone wants to pay more money to get to a higher efficiency level on a natural gas boiler. But we can get higher efficiency levels for specific customers. We have plenty of experience in designing higher-efficiency units.” A Holistic Approach Boilers are not standalone units like a refrigerator or an air conditioner. Because of this, their real efficiency levels often depend largely on the other operating systems to which they are connected. For instance, a high-efficiency boiler won’t be as efficient if the distribution system it is connected to is an older, less efficient one. In distribution systems with baseboard or old-style radiators, not as much heat is distributed through the radiators and into an industrial space. When water makes its way through the building and back into the boiler, it isn’t as cold as the boiler would like it to be. Then the boiler, even one with a high efficiency rating, will consume more energy to heat that water than end users might have expected when purchasing it. That’s because the colder the water that comes back into a boiler, the more efficient that boiler operates, O’Donnell says. If warmer water comes back in, boilers, even high-efficiency ones, will consume greater amounts of energy each year. But in an industrial space with newer radiators that pull more heat out or rely on floor-radiant systems in concrete slabs, the water that comes back to boilers is colder. Now high-efficiency boilers can actually heat that water without consuming as much energy. “A lot of people are disappointed if they have an older heating system,” says O’Donnell. “They are not getting the returns that they expected. Today, though, people more often understand that they need distribution systems that radiate enough heat out so that the water comes out cold.” Rohrs says that a growing number of end users recognize that the efficiency of their boilers won’t matter much if the systems they are connected to are consuming gobs of energy every year. Even more importantly, manufacturers are recognizing this fact, he says. He points to the manufacturers of pumps. Today, these manufacturers are focusing on creating pumps that do consume less energy. When these high-efficiency pumps work with high-efficiency boilers, the end result is an overall system that consumes far less energy each year. “It is refreshing to hear pump makers talk about system efficiency,” says Rohrs. “They understand that their pumps are also a driver of the overall efficiency of a system. That’s a nice change.” Lara says that boiler technology does not necessarily change quickly. To see truly big differences in energy efficiency, you’d have to go back to the boilers that companies manufactured 25 or 30 years ago. This doesn’t mean that efficiency improvements haven’t happened in the last five or 10 years, he notes. It just means that the biggest improvements to how efficiently boilers operate already took place decades ago. But more substantial efficiency changes could be coming in the future, Lara says. Tougher environmental regulations imposed by state and federal governmental bodies might have an important impact on boiler efficiency in the coming years. “Everything that has to do with regulating carbon dioxide and a company’s carbon footprint could result in more efficient boilers,” he says. “Companies are already more conscious of their carbon footprints today. With a boiler, one way to better control its emissions is by tuning it, making sure that you are burning less fuel. You do that by improving your combustion tuning.” Today’s boilers don’t require much maintenance or cleaning. That’s because most boilers sold today burn natural gas. Lara explains that almost all the users on the West Coast and in the Gulf region of the country burn natural gas in their boilers. Only a small number of users in the Northeast today apply for permits to burn light oil through the winter months. Some older boilers still in operation—not many—might even burn coal or wood. Lara believes that the owners of these boilers, and those that burn light oil, will have to work harder to keep their boilers clean. The controls on boilers today are also more efficient, according to Lara, resulting in even more efficiency gains. “Older boilers use controls that were based on old technology,” he says. “That instrumentation wasn’t efficient as what we have today.” Lara compares the way boilers operated in the past to the old carburetors that came with older-model cars. Older boilers had jackshafts that moved their air dampers and the fuel valves. In these old boilers, then, everything depended on a single device. Just like with an old carburetor and its possible negative impact on a car, if something gets dirty or if something sticks in an older boiler, the combustion tuning will suffer. “Just like in a car, the main thing that you need to control in a boiler is the amount of air that you are putting into it,” states Lara. “You need a certain amount of air to burn your fuel. You need some excess air to be on the safe side. If you put in too much excess air, you end up pushing heat out. That lowers your efficiency.” Today, though, boiler owners don’t have as much to worry about. He says that the technology in boilers today is top-notch. This is partly because of independent flow meters that make sure boilers are operating as efficiently as possible. No 100% Mark Some end users might believe that one day they’ll be able to buy a boiler that operates with a 100% efficiency rating. But that will never happen. As O’Donnell says, there will come a point at which boilers will reach a maximum efficiency level. No boiler can ever be 100% efficient. Because of this, savvy industrial users are looking at their entire heating and cooling systems—including boilers—when trying to boost the energy efficiency of their warehouses, distribution centers, and factories. For instance, in addition to purchasing high-efficiency boilers, industrial users might also take a closer look at the pumps that move water through their buildings. Instead of relying on pumps that are always moving water at full speed, they might invest in pumps that vary their operating speeds depending on need. “Pumps operate at much higher efficiencies as they vary their speeds,” says O’Donnell. “It makes sense for users to look at pumps and their whole systems, and not just their boilers, will looking to create a more efficient operation.” To save money, some users might install two high-efficiency boilers that handle most of their heating needs throughout the year. They will then purchase third and fourth boilers that are less efficient, and less costly, for redundancy reasons. These backup boilers come on one by one as needed, possibly turning on only when the outside temperature falls to 0°F. But 90% of the time only the high-efficiency boilers will run. “Overall, the boiler bank is still efficient,” says O’Donnell. “But the initial cost to install it because part of the bank is made up of these moderate-efficiency boilers in addition to the high-efficiency ones is much less. Sometimes it just doesn’t make sense for companies to invest in only high-efficiency boilers.” What has led to the increase in higher-efficiency boilers? He points to advances in technology. Even 100 years ago, people understood that if the water got cold enough the efficiency levels of boilers would increase, he explains. But the materials that boilers were built out of back then couldn’t handle those higher efficiencies. It wasn’t until manufacturers understood how to form and use stainless steel that they could concentrate on boosting the efficiency levels of their boilers. It wasn’t until they could make heat exchangers that could handle the high-efficiency environment that boilers’ efficiency levels could steadily increase. “It was very expensive at first to get the higher-efficiency boilers,” says O’Donnell. “But as technology matures, it gets less expensive. That has happened here, too. Building owners today are definitely more aware of how efficient boilers can become. They are always looking for efficiency improvements.” Improving technology is also allowing users to better monitor how efficiently their boilers are operating. O’Donnell says that end users today can log in from their phones, tablets, and laptops to monitor how much energy their boilers are consuming. “The whole concept of the Internet of things is changing everything,” he says. “Your refrigerator can talk to your oven and garage door opener. That is kind of where we are at. We can tie together the different systems in your building so you can see your energy usage over time. If something happens with your boiler, maybe you’ll get an alarm on your phone that something is going on. You don’t have to wait until the building gets cold. If that happens, you’re already behind the 8 ball. If you get a notice from the boiler itself, you can react and fix the problem right away, before the building even gets cold.” The Tankless Alternative Boilers aren’t the only high-efficiency options industrial users can turn to for hot water. Tankless water heaters are becoming increasingly popular choices for industrial users, especially those whose buildings are smaller, says Jason Renner, senior product manager for Bradley Fixtures Corporation, the manufacturer of Keltech electric tankless water heaters. Renner adds that the footprint of an electric tankless water heater is about 3 square feet. A system of boilers, though, can fill an entire small or large room, he said. Those industrial users who are short on space, then, often consider tankless water heaters for the space-saving benefits alone. It also costs less to install tankless water heaters, Renner says. And the heaters are highly efficient, often consuming less energy each year than would a comparable boiler. Boilers, though, do have one big advantage over tankless water heaters: Boilers can act as dual-purpose machines, heating not just water, but entire factory and warehouse buildings, too. Tankless water heaters heat only the water that industrial clients use, Renner points out. Industrial users, then, have to look at several factors when deciding whether a boiler system or a tankless water heater are the right choice for them. Industrial users who need to hit precise water temperatures in a short period of time might be better off with a tankless water heater, Renner says. “Tankless water heaters have a faster response time. They are more precise when it comes to getting water to a specific temperature in a short amount of time,” he explains. “If you are a commercial user where your water temperature is critical to whatever process you are doing, electric tankless might be a better, faster-acting, more precise solution. You will see less pressure drops going through a tankless heater.” Renner says Tankless heaters are still a relatively new technology, first hitting the industry about 20 years ago. Because of this, many end users still think only of boilers when it comes to their water-heating needs. As companies like Bradley Fixtures educate commercial users about the benefits of tankless water heaters, though, more industrial and other commercial clients are taking a chance on the equipment, Renner says. “The message is getting out there. But there is still a long way to go,” he remarks. “I don’t think everybody in this country is thinking of electric tankless water heaters for industrial commercial applications. We still have a ways to go to educate everyone about the advantages of tankless heaters.” Renner acknowledges that tankless heaters have a benefit over more traditional tanked water heaters, too. They are more energy efficient—something that should interest industrial users who need to cut their expenses each year. Tanked water heaters hold, heat, and maintain water at a certain temperature all the time, Renner continues. But tankless heaters only consume energy when they actually need to provide hot water. “Our heaters are intended to only use the minimal amount of energy needed to bring water up to that set point,” he states. “Others over-energize the heating elements until they hit the set point. We are applying the least amount of energy to maximize the efficiency, to make our tankless heaters as efficient as possible.” Payback Matters What matters most to industrial users—and all commercial end users, really—is the payback period that comes with a high-efficiency boiler. “Everyone wants a short payback,” says Rohrs. “The first two questions out of everyone’s mouth are ‘How much will it cost?’ and ‘How much will it save me?’” Upgrading to a more efficient boiler system can bring solid savings. Rohrs says that depending on how inefficient a user’s old boilers are, upgrading to new ones could bring them yearly energy savings of 30 to 50%. Boilers that come with outdoor reset control could reduce industrial users’ energy bills by even more, Rohrs says. With outdoor reset, boilers react to the outside temperature. If it is 50°F outside, boilers equipped with outdoor reset control might heat water to 120°F to heat a building. If it is instead zero degrees outside, boilers equipped with this technology might instead heat water to 180°F to heat the building. “We have a weather-responsive building when we are using outdoor reset,” says Rohrs. “That has been very important. That is a big driver for efficiency.” Rohrs predicts that the next driver of energy efficiency will be boilers equipped with indoor reset. This way, boilers will react not only to the temperature outside but also conditions inside a building. “This way we will make boilers responsive to the very specific heat loss of the structure,” he says. “We are looking down the road at indoor feedback. We think that will be the next big advancement for efficiency.” Dan Rafter is a technical writer and frequent contributor
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