Controlling Comfort and Cost

June 13, 2012

HVAC systems use a lot of energy-by some estimates, anywhere from one-third to one-half of all energy consumed in industrial, commercial, and residential settings. To achieve greater efficiencies and save money while maintaining comfort levels, facilities operators adapt new technologies. These technologies, in some cases, are being financed through utility incentive programs and government grants.

The “sheer level of energy consumption” is indeed the greatest challenge involved with HVAC systems, notes Trevor Wende, vice president of marketing at Advantix Systems. The company manufactures liquid desiccant air-conditioning and dehumidification systems.

Another HVAC challenge is the ability to properly control both the temperature and humidity components in the environment, Wende says. Temperature is the most visible and easy to measure, he points out.

“People think about that in relation to comfort,” says Wende. “Virtually every person can tell you what they set their thermostat at, in terms of the dry bulk temperature. Virtually none of those people could give you an accurate impression of what the relative humidity is in the facility, even though that has an equally important bearing on comfort as well as energy consumption in that building.”

Buildings were inefficiently designed about 30 years ago, Wende says.

“There was a not a lot of ventilation air being brought in,” he says. “There might be a lot of window glazing to let in light. The plug load, the appliances, and the machines-if it’s an industrial facility-are not efficient, so they’re generating a lot of heat,” he says.

Over the past few decades, efficiency has taken more precedence. Standards developed with respect to the amount of air being ventilated in the building, the amount of insulation used in the building to thermally insulate it-even the glass has an impact on the amount of thermal energy being brought in from the outside.

“You’ve got all of that equipment to plug load everything inside of the building generating less heat because those things are becoming more efficient,” adds Wende.

“In the 1980s, as an engineer who’s designing the HVAC for a facility and as a company manufacturing the HVAC, you could basically ignore humidity because the thermal load-not including the humidity-was so great that any amount of equipment you would design for that facility would be sufficient to take care of the sensible load, the thermal, and heat load, and then get that marginal amount of humidity out of the air as well because it had to cool the air down to such a degree to deal with that thermal load.”

These days, engineers designing facilities and HVAC equipment manufacturers embrace the idea that the selection of standard equipment is no longer appropriate to treat the combination of temperature reduction and humidity control.

“Conventional equipment is optimized just for temperature reduction and does not really do a great job of humidity control,” says Wende.

Not having the right equipment means losing control of the building’s humidity, which has a bearing in terms of comfort cooling, he adds.

“People are not going to be very comfortable,” says Wende. “There are very tangible air-quality issues. There begins to be property damage due to the amount of moisture, potential condensation, and microorganisms that are growing in that facility.”

The temptation is to oversize equipment, which leads not only to a loss of control of humidity, but also the power bills, Wende says. Average commercial buildings bring in a minimum amount of fresh air to ventilate for healthy breathing for occupants and provide humidity control in the 5060% range, Wende says.

“Those buildings, because of energy efficiency measures and increased ventilation standards, are at the borderline, where they would start to benefit from dealing with humidity more directly,” he says. “But there are a lot of facilities past that.”

An ice skating rink, for example, needs to keep the moisture out of the air in order to maintain desired conditions. An industrial facility such as food processing, pharmaceutical, or plastic injection molding has to maintain a low humidity to maintain consistent production process and quality.

Wende notes a trend toward adopting solutions for humidity control beyond the thermostat reading.

“If you’re stuck in that mode, you’re either in an improperly controlled humidity environment or a reasonably controlled environment with very large energy bills,” he says. “Typical options available to facility managers focused on the oversizing option with conventional equipment. Some manufacturers started to build specific pieces of equipment that were purposely oversized.

“The solid desiccant wheel is now a direct approach; however, it’s not a very elegant system. Because of its physics, it requires a significant amount of heating rather than cooling to remove the moisture. It lets a lot of that heat slip back into the facility that you’re trying to cool and dehumidify. Even though it’s a more direct method of treating the humidity, it ends up not being an energy-saving mechanism for the average facility.”

Wende points out that Wal-Mart, for example, has used the solid desiccant approach “to achieve modest energy savings because of the way it was implemented.

“That’s good progress,” he says. “They’re fully acknowledging about having to think about humidity control as its own separate challenge outside of just controlling the temperature of a space. That’s the state of the industry in the average industrial and commercial facility.”

Liquid desiccant creates an avenue by which a facility can directly treat humidity not through an over-cooling approach but via a direct chemical attraction of moisture out of the air, Wende points out.

“It doesn’t require nearly as much heat, and it doesn’t drift that heat back into the space or allow that heat carryover effect back into the area you’re treating,” he adds. “This is a true energy-efficient approach. Layered on top of that because of the much more modest temperatures at which you operate is the ability of liquid desiccant to operate based on renewable or waste heat sources.”

The efficiencies derived by those opportunities can start to cut more than 50% out of a facility’s cooling load, Wende says.

“In a more conventional office building, relatively low on the need for a humidity control spectrum, we’ll see an average of 30%,” he says. “It’s different doing that same process with the plug-and-play equipment in a system that has a higher demand for humidity control. A big box store is a great example, because they’ve got all of these open doors and a lot of fresh air coming in that’s very humid, or a food processing facility with a lot of wet processes happening inside. That’s starting to get into the range between 30 and 50%.”

In projects that leverage a renewable energy source, the efficiency savings can range from 5080%.

“Those are savings compared to accomplishing that same job with the standard rooftop or air handling unit with a chiller of average efficiency,” says Wende.

Intelligent Power & Air Solutions (IPAS) designs air and dehumidification systems and provides energy management for commercial and US Department of Defense. The company started utilizing Advantix Systems-formerly of Israel and now based in Miami, FL-in its designs.

“We look for ways to integrate it with renewables or waste heat sources in order to more efficiently energize the systems,” says B. J. Elliott, company president. “We’ve been watching liquid desiccant for a while.”

He’s watched it with an eye to some of the issues it’s had in the past. One such issue is the carryover lithium chloride that would erode the ducts and cause major problems. But the systems make sense from the standpoint of moisture removal and the energy efficiencies achieved using waste heat or renewable energy sources, he adds.

Comfortably Cool Heels
IPAS recently used Advantix Systems and a customer energy management/control system in a retrofit with Bel-Garden Bi-Rite Supermarket, a 27,000-square-foot family operation in Baltimore, MD. One of the challenges for supermarkets is a tight profit margin, Elliott notes.

“They’ve got to sell $52 in product to make $1,” he says, adding that because of the tight margins, energy is a “very big deal” for them.

“These stores are massive energy consumers when you look at their infrastructure,” he adds.

Credit: Ernie Witham

The store environment was not consistently comfortable-refrigeration would fail, and utility bills shot up in the summer. “A lot of research has been done on the impact of humidity on refrigeration cases,” says Elliott. “You traditionally deal with humidity in these situations by overcooling. You’ve also got refrigerator cases that are giving off cold air temperatures every time they’re open, so you create a very undesirable condition for the shoppers.”

The supermarket’s owner, Sandy Vary, was looking to replace a 20-ton air-conditioning unit primarily serving the refrigeration and freezer cases in the store. Elliot’s company decommissioned the 20-ton air-conditioning unit and, after about two days of operation, brought the facility to the point where it could maintain a relative humidity in the store of about 40%.

The incremental cost for the system was about $40,000 to $50,000, and the supermarket saved about $30,000 to $40,000 with a payback of between one to two years, which is typical of a retrofit, says Wende.

After the Advantix system was operational, IPAS incrementally raised the set point until it reached 77°F with a 40% relative humidity.

“The comfort level was better, because people weren’t freezing in the store,” notes Elliott, adding that the added comfort level invites people to stay longer in the store, increasing the chance they will buy more.

It also created a more favorable environment for the employees.

“Not only do you not get hit in the face with humidity, but you also are not freezing in those sections of the store where you’ve got the cases,” says Elliott.

Another task for Elliott’s company was to identify the impact of humidity on closed-door cases.

“With each of these cases, there are two sets of heaters that deal with the fogging and the humidity of the case,” says Elliott. “Every time someone

Credit: Ernie Witham
The right equipment can control indoor temperature and humidity.

opens the door to a freezer case, an emollient heater activates to stop the doors from defrosting. The grocery industry knows if people can’t see in those doors, they don’t sell product, and they won’t open the door to look what’s behind it.”

IPAS then took the next step for the control system: limit the activation of the door heaters when the relative humidity in the store was maintained at 40%.

“We only really needed to operate the door heaters when the cases went through the defrost cycle because the store was constantly being maintained at 40%, and they weren’t fogging up,” says Elliott. “The only time they would fog up is when the cases go through a defrost cycle, which is actually defrosting the coils at the bottom of the cases.

“At that time, the temperature in the case is changing, and moisture is coming off because you’re melting ice. We’re controlling that now.”

IPAS is cycling the cases for two hours before the defrost cycle and for a little bit of time afterwards. That equated to a large energy savings of about $8,000 to $12,000 annually, Elliott says. IPAS also noted that the coils weren’t freezing up as quickly as they had before.

“We had been running a 24-hour hot gas defrost on all of these cases, which has a major impact on the refrigerator rack system we have been monitoring,” says Elliott. “We can check spikes in energy and in usage based on that. We’re able to change that defrost cycle from once every 24 hours to once every 48 hours.”

That has had a tremendous impact on the energy consumption of the refrigerator rack of both the low-temperature and the mid-temperature rack that runs all of the cases, notes Elliott.

“That’s the evolution we’re going through in savings for the supermarket,” he says. “Also, just by maintaining the humidity in the store, we know that the refrigeration rack once again is operating more efficiently. It’s not having to work as hard. We’re not adding heat through the door heaters, so we can equate another $5,000 to $7,000 in savings to the efficiencies of the refrigeration rack.

IPAS chose the Advantix DuHybrid system.

“It allows the store owner to use renewable or waste heat sources, but also have a back-up compressor in case for some reason we’re not able to provide that,” says Elliott. “This is the next evolution we’re in with the system. The refrigeration racks produce a lot of heat. It’s very common for people to pull waste heat off of a refrigeration rack, so we installed a water-cooled condenser unit.”

Correct ventilation aids air quality.

IPAS took the hot discharge line as it comes out of the compressor rack before it goes to the condensers on the roof. That water is used to fuel the regeneration side of the Advantix unit. That part of the system is mounted in the ceiling of one of the refrigeration boxes underneath where the unit is installed on the roof. The new system also provides additional cooling and dehumidification compared to initial system installed.

 Elliott points out that not only does the liquid desiccant system offer the ability to pull off the waste heat and use renewables, it also provides an inherent air-quality improvement.

“It pulls particulate out because it’s running the air through a filtration medium that’s being saturated with the lithium chloride,” he says. “Bacteria, molds, and viruses can’t exist in this lithium chloride solution, so you’re not only cleaning particulate, you’re providing a higher quality of air to this facility.”

That’s important for the grocery store client not only for odor reduction, but also for the health and well-being for the shoppers, Elliott says.

“It’s repeatable in every store,” he says. “Every store has this infrastructure. Most times, they’re already pulling some waste heat off of their compressor to create hot water or heating in their store, so it’s a very real solution to deploy anywhere.”

Efficient Commissioning
Eaton Energy Solutions provides consulting services that help clients manage, maintain, and operate their facilities efficiently. Services include commissioning and retro-commissioning of buildings, as well as energy audits. With HVAC technologies having become more sophisticated, facility operators are now opting to upgrade their systems to achieve more energy efficiencies, notes Douglas Gray, P.E., Eaton’s Southeast business development manager.

Case in point: Georgia Southwestern State University (GSW), where most of the 48 buildings on its campus date to the late 1950s and early 1960s,

Jim Shelton, National Sales Manager, Panasonic Home & Environment Co.

with a few dating back to 1920. Plans to modernize the campus buildings’ heating and the cooling began years ago with window units, then moved into central HVAC systems. Presently, the campus is upgrading central HVAC systems installed in the early 1960s, plus one system that was installed as late as six years ago that has presented problems.

“With the exception of three facilities that don’t need any HVAC system, we have all of our buildings air conditioned and heated,” says George Smith, GSW’s physical plant director. “Eaton and others have helped us to update at a reasonable cost. We hope the systems will last 20 to 25 years or more.”

After Eaton was selected by GSW to provide energy services, “the first thing we did was to assess the systems in the building to understand what condition they’re in and get a picture of what needs to be replaced and upgraded,” says Gray.

Designing a solution was the next step. Challenges included staying within a tight budget and working in a construction window that accommodated the campus activities.

“One of the academic buildings is used throughout the school year so the only chance to renovate it was in the summertime when there were no classes in session,” notes Gray. “To accomplish that, we were going to have to do this in phases over several years because we couldn’t get all of that work done in one single summer.”

As Eaton progressed through the design, the company identified potential systems that could offer optimal efficiencies to the buildings in which they would be placed. After university approval, Eaton designed the infrastructure, including a Trane chiller, a new boiler system, and a Trane makeup air unit that served that academic building and an adjacent building. Gray says Eaton’s designs are “vendor independent,” with systems chosen for their ability to deliver results within a budget, often part of state contract
bid work.

“Our approval authority for all projects we do is $300,000,” says Smith. “Doug [Gray] had to figure out a way and specify the resources that were available in order to keep the cost down to our cost limitation. We did not want to go to the Board of Regents and identify a one-time cost of $1.5 million. He worked with that cost limitation and brought that project in under cost.”

Gray says when Eaton does its designs, the company simultaneously crunches construction cost numbers to get an idea of the final price tag.

“That can be difficult sometimes when you’re doing a project, because certain equipment needs to go in during the first phase, and there aren’t many options for splitting up further than that,” he says. “That was an issue; we got all of that done.”

Credit: Cummins
The average commercial building brings in minimal fresh air for circulation.

Six years down the road, Gray says the system is proving its intended efficiencies. “One of the areas where HVAC systems use a lot of energy is with fan energy, which can be quite significant in a centralized fan system.”

Eaton instead opted to use individual fan coil units in each classroom. A new building automation system also was installed to manage the various components. At the same time Eaton took out the ceiling to replace HVAC equipment, the company also installed new T8 florescent lighting to optimize the energy savings. Those energy savings were realized almost immediately, with a “tremendous drop in the cost and energy use in the facilities,” notes Smith, adding that the university is nearing the start of its return on the investment.

More work is on the horizon for GSW, including an emergency repair project for the replacement of two 240-ton chillers in a student center, as well the replacement of HVAC units in the school’s health facility. As for the work completed to date, Smith says the feedback on the comfort level has been positive, with a significant reduction in complaints about the air conditioning. Plus, the installation of an energy control system has cut back on HVAC maintenance and repair efforts.

“We control the systems now from as far away as Fort Valley, Georgia, and we don’t have the call backs that we used to that would cost us time-and-a-half for that person’s labor,” says Smith. “When you couple together the HVAC systems that are being upgraded and look at the labor of our shop personnel to maintain the systems, we are saving a lot of money.”

Those funds are being applied to other projects to include HVAC projects and facility construction projects around the campus.

“Eaton has done a tremendous job for us,” says Smith. “They’ve been very conscious of our time requirements, our scheduling for classes, and the

Photos: Advantix
The newest EMS systems can integrate renewable energy.

equipment they designed for us is working just as it should,” says Smith. “The efficiency is proving itself in the form of energy savings.”

The return on investment (ROI) on HVAC components depends on the technology used, Gray points out.

“For a retro-commissioning service, which is a building tune-up, that has a payback of between six months to two years,” he says. “Controls and upgrades will typically have a payback of three or four years. The same would be true of installing variable frequency drives. When you are replacing chillers or entire HVAC systems, the payback for those can be more than 10 years. It depends on what is there to begin with. It’s very important to evaluate beforehand what it is that you’re going to be putting in, because it can be quite different from one project to another.”

Owners of new and properly maintained HVAC systems can expect 15 to 20 years out of them, says Gray. Financing options can vary according to available federal, state, local, and utility incentives.

“A lack of funding is one of the challenges for public agencies, so where, in the past, they had been able to finance the replacement of an HVAC system through their own internal sources or allocations from the government, now it’s becoming more common that they need to look at alternative ways to finance upgrading HVAC projects,” says Gray. “One of the ways people are doing that is through energy savings performance contracts.”

Additionally, most utilities now have rebate programs for demand side management programs, which can include rebates for a host of energy technologies, such as variable frequency drives. Variable frequency drives have come down tremendously in cost, making them more financially feasible, Gray says.

“The control systems available now are very robust and have a lot of capabilities to them, so people are starting to utilize more all of that capability to save energy through different strategies like the demand controlled ventilation or sophisticated temperature reset strategies during unoccupied periods in the space, automatically turning on when people occupy the space.”

Chill beams are another sophisticated technology, Gray says.

“It’s a system that cools the air right in the space instead of cooling it in a handling unit and pushing it around a building-it’s like a radiant cooler

Credit: Advantix
The latest control systems are robust, with a lot of capabilities.

that just provides cooling in spaces rather than in a central location.”

Another technology getting attention is connected to “net-zero” buildings, Gray says.

“The building is generating power or energy through solar PV or solar thermal heating,” he says. “The energy they require is generated onsite. More people are starting to look at the way we will be conditioning buildings in the future.”

Standards and Protocols

Scott McGinnis, regional sales manager for Munters, points out that all building owners, engineers, and architects have to comply with two standards. One is ASHRAE 62.1, which addresses ventilation.

“Ventilation air costs a lot of money to dehumidify and costs a lot of money to heat up,” says McGinnis. “In the past, a lot of building owners have been shutting off their outside air intakes to save money, but people now understand the disadvantages of doing that.”
It produces poor indoor air quality, and the inside contaminants aren’t diluted, he adds.

“The US Department of Energy did a study talking about how schools don’t have enough ventilation air and the children of these older schools have lower standardized test scores,” says McGinnis. “There’s a lot of evidence that bringing in ventilation air is good for the occupants.”
The other standard that’s mandated is ASHRAE 90.1, the standard that directs building owners, engineers, and architects to design buildings that use very little energy, McGinnis says, adding that the two concepts “are in conflict with each other.”

ASHRAE’s applications manual recommends using a dedicated outside air system to bring in ventilation air and over-dry that air so that as it comes into each space, it can absorb all of the moisture content in the space, McGinnis says.

“This allows whatever other device is controlling sensible temperature in the space to be smaller, run less often, and to run more efficiently because it’s not trying to pull in any moisture out of the air,” notes McGinnis.

One of the challenges for building owners is equipment costs,  McGinnis says. “There’s a feeling that the cost of dedicated outside air systems is very high and the technology to be able to deliver the lower dewpoint hasn’t been around for a very long time,” he says. “There’s also some skepticism about changing when it’s been done a certain way for a long time.”

Munters designs equipment that addresses those problems and can be more energy-efficient than the dedicated outside air systems of the past and deliver “ultra-dry” air using less energy, says McGinnis. One way to address it is through energy recovery units that recover the energy spent to cool, dehumidify, or heat a building by pulling it back out of the exhaust air. A second method is desiccant dehumidification, McGinnis says.

“Desiccant wheels can pull a lot of moisture out of the air for very little energy,” he says. “The units we promote most of the time are humidity control units. That’s a process where you bring in outside air, pass it through a coil, chilled water, or a combination of chilled water and DX, and you take the air down and cool it off.

“You bring some of the moisture out of it, but at a temperature much higher than you would want to blow into the space. It’s a lot wetter than what you want to blow into space, and it definitely does not exceed or lower the moisture level in whatever you’re designing for.”
Air is passed through a desiccant wheel that rotates about eight rotations an hour between two air streams, the first being the process or outside air stream, McGinnis says.

“As we go off a DX coil at 60 degrees [Fahrenheit] and saturate it, and as we go through the desiccant wheel, we would come off that wheel the equivalent of 45 degrees [Fahrenheit] saturated or dewpoint, but with some sensible energy added back in to do the natural occurrence of the process,” he says.

McGinnis points out that for the tonnage it takes to make 60°F air, the system can deliver 45°F dry air to the space.

“We’re using less energy than we’re using in a dedicated outside air unit, but delivering 15 degrees lower on the dewpoint scale than you could five years ago,” he says.

“While one of the compressors is running, we have to reactivate our desiccant wheel, so we take the condenser heat and, instead of blowing it out of the unit like a typical air cool condenser unit would do with a condenser coil and a prop fan, we reroute that hot air off of the condenser coil back to the opposite side of the desiccant wheel,” says McGinnis. “The desiccant wheel has collected a lot of moisture out of the supply air, rotates over to another outside air stream—a condenser air stream—hot air hits that wheel, and that releases that moisture back out into the atmosphere.”

The humidity control unit process can be put in place with energy recovery attached to it, McGinnis says. For instance, at a laboratory that has to avoid cross-contamination, a system can consist of a plate exchanger, a coil, and a desiccant wheel, he adds.

The energy savings derived depend on the standards being used, McGinnis says.

“If you look at current 90.1 standards—requirements for how to design package DX equipment—we can exceed that by 30% if it’s a non-energy recovery unit and just a desiccant unit,” he says. “I’ve done some runs where we’ve put energy recovery in the perfect environment and found a sweet spot where we can save up to 75% of the tonnage of processing the ventilation air.”

In that case, depending on run hours, paybacks can be derived in less than a year, he says, adding that the rule of thumb is to aim for an ROI of less than three years.

Access and Control
Today’s building owners want to know how to access, collect, and analyze their HVAC system and building system data to improve the performance of the various systems, says Andy Kowalik, marketing strategy leader for Trane/Climate Solutions, Ingersoll Rand. Kowalik explains how HVAC systems can be integrated into building infrastructures to “collect and analyze the performance data on an ongoing basis so customers can optimize the system performance. We’re finding that has very nice energy and financial benefits.”

Customers are looking for a payback period, says Kowalik.

“Typically, customers will invest in either upgrading or refurbishing the system and look to get a payback on that investment over a two-year window,” he says. “What they’re looking at more than an ROI is a total cost of ownership.

“It used to be customers would look at what the installed costs—the capital expense of what it costs to get the system and install it,” says Kowalik. “Now customers are really looking at the lifetime of a system in a building over 15 to 20 years. They look not only at the initial cost, but what does it cost to maintain it, and what are the energy costs for running the system. That’s a total cost of ownership analysis.”

Trane’s EarthWise systems are designed to reduce total cost of ownership with a lower initial cost and reduced ongoing operating costs. The systems include a low-flow, low-temperature, high-efficiency design using smaller pipes and pumps for fewer natural resources and less energy for water circulation. The design for colder water results in colder air distributed throughout zones in smaller ducts, using less energy for fan circulation and less material for the ductwork. It also results in a quieter operation and reduces relative humidity in the building to improve indoor air quality.

Trane Intelligent Services collects a variety of data on the system from the chiller, the air handlers, the flow, the pressure, and the temperatures.
“It’s used to provide some trend analysis on performance,” explains Kowalik, who also notes that “customers are now looking over the lifetime of a system, so they’re examining month-to-month and year-to-year trends for performance.

“They can sometimes detect what might be happening and do system maintenance on a piece, as opposed to waiting for it to fail and needing to replace it,” he continues. “In the past, customers looked at services as what we called ‘break and fix’. They’d have a service agreement, and if there was something wrong, we would get called to go out and diagnose and repair.”

Driving Motorized Efficiency
One of the challenges of facilities owners is meeting efficiency standards, points out Kim Baker, vice president of application engineering for NovaTorque. One tool to achieve high efficiency, according to Baker, involves utilizing variable speed motors which can help customers “meet or exceed the efficiency requirements that are in place,” he says.

NovaTorque offers a permanent magnet axial technology, which enables delivery of high efficiency “over a broad range of speed and load,” according to Baker.

Baker agrees with others in the industry that variable speed and variable frequency drives are key moving forward. “The trend to deliver air flow at the required level has been in place for some time. It’s an important trend that’s continuing. Another trend we’re going to continue to see is a move towards permanent magnet motors that have an inherently higher efficiency capability than induction motors.

“Part of the solution is providing variable speed capability,” adds Baker. “If you use a variable speed technology, you can deliver air flow that’s at a comfort level appropriate for the heating or cooling situation, and realize substantial energy savings at the same time.”

“A lot of times with older systems, budgets are always a factor,” points out Joe Koepke, an applications engineer in the building automation group for Yaskawa. “A big challenge is taking an older system and figuring out a simple way to cost-effectively change that system over to a more efficient, more reliable and easier-to-use system.

Yaskawa manufactures variable frequency drives for the control of three-phase electric motor speed in several applications, including HVAC. Variable frequency drives can reduce the speed of the motor and energy usage up to half or more, says Koepke.

Most end users can expect a payback from one to three years, Koepke says.

The Benefits of Automation
Koepke believes variable frequency drives also make it easier to automate a system.
“There’s a trend in commercial HVAC that’s going toward BACnet, an open data communication protocol,” he says, adding the components are more easily able to communicate with one another to help control the environment.

With HVAC systems, “you want to make sure that the temperature and the humidity is comfortable when you have people working and can you basically shut it off and save energy and money when there are not people there,” says Stuart Lombard, CEO of ecobee. The company manufactures Wi-Fi enabled “smart” thermostats.

“A facilities manager may have many HVAC systems distributed over a large area, so any control of those and making sure you’re running the right occupancy schedule at the right time drives the return on investment,” he adds.

Most people are familiar with the simple thermostat with the plastic cover.

“The challenge is when somebody gets into that thermostat, they change the schedule or the settings,” says Lombard. “We did one study for a large facilities manager where people were setting the cool as low as 65 [degrees Fahrenheit] and the heat as high as 79 [degrees Fahrenheit], and they had it running all weekend when they didn’t have people there. There are huge opportunities for energy savings.”

Another common scenario in offices is that a manager may feel uncomfortable to ask for the facilities manager to dispatch a truck to examine the HVAC system. One of ecobee’s clients, a retail operation, had a misconfigured HVAC system that was running 100% of the time.

“Normally, the manager would never know because nobody looks at it,” says Lombard. “He got our system and could see online that it was running 100% of the time. It was misconfigured. He saved $7,000 in that first year in that one location by having the right occupancy schedule in the right place at the right time, reducing onsite service calls and fixing the misconfigured equipment that he had.”

Today’s commercial control technology includes building automation systems and wall-mounted programmable thermostats with plastic covers.

Trends going forward include advanced controls like free cooling, economizers, and fresh air dampers to be able to cool a building rather than using air conditioning when outside conditions are favorable, Lombard notes.

“That’s a big move we see a lot of with our customers,” he adds. “They seek better management of electrical loads, so our system incorporates the ability to monitor electricity usage in the facility to reduce electricity usage and have better analytics and reporting. Those who have multiple facilities can see which are the biggest energy users and where they should focus their energy efficiency efforts. It allows you to target those ones that get the biggest bang for the buck.”

One such installation occurred recently at High Street Baptist Church in Springfield, MO. Chris Talburt, facilities manager, installed 32 ecobee EMS thermostats in the 100,000-square-foot facility to achieve energy efficiencies. The thermostats were installed them at the end of December to replace an inefficient system that dated back to the 1980s.

“They took too long to program everything, didn’t do what we wanted, and really didn’t give us any sort of energy savings,” says Talburt.

“Additionally, we could no longer get parts when they broke, which sped up our timeline for replacement.”
Although the system hasn’t been in long enough to determine a long-term efficiency savings, Talburt notes that he observes the church has knocked about 30% of the run time on the HVAC system.

“They have a formula with the current temperature, which may indicate it’s only going to take 10 minutes to heat up the room,” he says. “Our standard program was to kick everything on two hours before. A lot of times it’s only coming on 10 minutes before; it’s really reduced our run time. We love the thermostats. They’re easy to install, easy to use, and they just look so cool.”

Silent Comfort

In many cases, the noise level regulation, or expected noise level, limits the performance of a product, so product designers try to reduce it by passive means, but, at the same time, they are using much more powerful motors, or operate the motor on the maximum, so they still provide the required airflow, but with a little bit less noise, says Yoel Naor, products director.

Draining more moisture out of the air allows an occupant to raise the setpoint temperature to 80 to 82°F, and still have the same comfort level while saving money on energy bills. With a device that can plug into an air-conditioning system, ICM controls can turn a single-phase motor into a variable speed motor without the cost of putting in a new system. Controls for HVAC systems help derive energy savings.

“You would be able to lower the energy consumption of a fan by about 25%,” explains Kevin Jobsky, marketing director for ICM Controls. “It controls the fan motor speed to create an environment in your home that features enhanced comfort and improved indoor air quality, but it also can reduce your energy cost by improving your overall system efficiency.”

Controllers utilized in residential and small commercial settings, such as convenience stores and educational facilities, can dramatically improve indoor environments—particularly when it comes to noise.

“We have one customer who bought about 100 of these to put on a retreat because they wanted silence for people who wanted to meditate,” says Jobsky.

Noise control for energy efficiency for HVAC systems is also the focus of Silentium.

“When replacing an old silencer, the savings are clear, but in many cases it may lead to the fact that they can reduce the airflow—air device RPM [revolutions per minute]—to be as it was in the old design or with the silencer,” says Naor, adding that this occurs because the RPM is lower, and the engine works on much lower resistance.

Education and Outreach
Xylem’s Bell & Gossett brand, which has provided systems application education for the HVAC and plumbing industries for 70 years, now offers continuing education for LEED professionals through its Little Red Schoolhouse training facility. The company was recently approved to do so by the Green Building Certification Institute.

Among the first seminars the Schoolhouse started to provide in that market sector are large chilled water design and modern hydronic system design basic to help professionals improve building system efficiency through the application of pumps and related products. Heating and air-conditioning systems are big energy consumers, notes Mark Handzel, director of building services marketing for Xylem.

“Because they’re big energy consumers, they become a big target area to try to improve that efficiency,” adds.

The Little Red Schoolhouse focuses on making sure professionals can design a system that transmits the right amount of fluid flow to the right places to ensure a comfortable environment, Handzel says. That includes design of all water-handling components, such as the boiler, chiller, pumps, and valves.

“The training focuses on properly selecting your pump so that you’re not wasting energy,” he says. “It focuses on balancing out the system so that the right amount of heating water goes to a certain part of the building and not to another. The end result is that everything is geared around efficiency.”

The Schoolhouse focuses a significant amount of educational efforts on variable speed pumping, Handzel says. “We try to get people to understand an HVAC load varies,” he says. “In the middle of the afternoon on a hot summer day, the cooling load is huge, whereas in the morning, it isn’t as big because it is cooler outside. To be able to take the difference in the amount of water you need and transmit it down to a slower operating pump that uses less energy is a big value.”

In doing retrofits, “to be able to go in and change the way a pump is controlled can make a substantial difference in the amount of energy it consumes,” says Handzel. “No engineer wants to design a heating or cooling system that’s too small. You always want to make sure you have enough to keep the building at a comfortable range. To do that, you sometimes overdesign a little bit more than you should.”

Techniques to address overdesigning focus on variable speed.

“It matches what the system needs with what is actually operating, where if you didn’t have something to match those needs, the pump would just run at the same pace all of the time,” he adds.

The Schoolhouse also teaches about steam systems, of which many exist, says Handzel.

“We teach how to design them and service them,” he says. “There are a lot of people who don’t know how to do that anymore. They see a building, and it’s very intimidating. We have a working steam system in the Schoolhouse where they can see how the steam is operating in those pieces of equipment. It’s very educational to be able to operate a steam system and see how steam traps and condensate pumps work, how a steam heat exchanger operates, and to see the impact in making changes in the system.”

Going forward, renewables will play a major role in HVAC efficiency, Handzel notes.

“It’s a huge opportunity, and it’s really where the market is going to start to drive,” he says, adding that the ASHRAE 90.1 design standard for energy use in commercial buildings is updated every three years.

“There are going to be many more buildings that meet with what they call net-zero energy buildings, which means they will produce as much energy as they consume,” he says. “Renewables are a big part of that, to generate some of your own power and to use very low-power consumption devices in your buildings so that you don’t need excessive amounts of energy.”

The unanswered variables are how long it will take to get there and how much it will cost, Handzel points out. He predicts the next five years will bring more efforts to fine-tune buildings to bring energy use down as low as it can go.

“There are various different LEED standards—Silver, Gold, and Platinum,” he says. “The next level above Platinum is to get to that net-zero energy status. It’s a big leap, but we’re hearing about a lot of research, and there’s a lot of investigation going into how to get there easier at a lower cost.

“Alternative energies for heating and cooling buildings will be a combination of a lot of things we know about. We know about solar thermal. We know about geothermal. What types of combinations of all of these systems will give you a system that is as close as possible to net-zero energy?

Those are the things we are focusing on so we can teach it in the future.”
Handzel says in the past, the concern of building professionals, when talking about variable speed, was how fast additional equipment would reap an ROI.

“Now they’re more focused on what’s right for the environment and what they need to build a building that people feel good about,” he says. “We’re seeing it in the fact that more specifications are requiring LEED-type construction methods.”

There’s a focus on making front-end investments in energy efficiency despite the tight economy, Handzel says.

“Building owners are focused on where they are wasting energy and don’t seem to be afraid to spend their money on those types of investments,” he says, adding that studies show that landlords can get more rent for a building constructed to a LEED certification level.
“The employees who work in the building have a sense of pride and focus on using less water and less electricity, and will help the cause by having that general concern for the environment.”

Handzel says this is an “exciting time in our industry, because it’s really evolving.

“We’re seeing renewed interest in education that drives people to come to our classes to learn more,” he continues. “We learn from our students. A lot of the creativity that people have in the industry is what’s going to help drive us toward net zero.”

About the Author

Carol Brzozowski

Carol Brzozowski specializes in topics related to resource management and technology.