Efficiency to keep us cool or warm grows more important every day.

By Paul Hull

If there is one aspect of saving energy that has shown its importance in this series on energy efficiency at work and home, it is that the control of our convenient equipment should be sensible. Control is not necessarily a manufactured device; it can be an attitude. The more I investigate the ways that people are saving energy and being efficient in their factories, offices, and homes, the more I learn that there is much common sense involved. And commitment.

“There is a big difference between energy efficiency and energy conservation,” notes Brandi McManus, energy services manager for TAC, one of the world’s leading companies in the provision of indoor comfort. “Energy efficiency is minimizing the energy used for each unit of output from a device. An example of this is an energy-efficient light bulb. This uses less energy to provide the same amount of light to a room. However, you only get the benefit of energy efficiency when the light is turned on. Energy conservation is turning the light off when it is not needed. Both efficiency and conservation are needed to save as much energy as possible in an office or home, while still providing optimal comfort.”

Energy-efficient devices for an office building mentioned by McManus include high seasonal energy efficiency ratio (SEER)-rated air conditioning units, compact fluorescent light bulbs, or high-efficiency water heaters. “Some energy conservation measures include time scheduling, the lights and HVAC equipment, using occupancy sensors in conference rooms and restrooms, and making sure the heating and cooling systems are designed to meet the needs of the occupants,” McManus adds. “Remember, both energy efficiency and conservation are needed to maximize energy savings. An energy-efficient light bulb that runs 24 hours a day—even when no one is in the room—is still not optimized for energy use.”

It’s conduct and control, isn’t it? In our quest to be constantly comfortable, we must exercise some good sense. Manufacturers of appliances have achieved impressive success in making their products more efficient, but some of the responsibility still rests on the shoulders (or fingertips) of the users.

You will discover that individuals and companies—who are experts in one area of energy efficiency—are expert in other areas, too. ObjectVideo offers software, for zoning in lighting installations, but the devices are also suitable for HVAC control. If you have found a supplier or adviser, who has demonstrated ability in one appropriate area, it may pay you to have the same person or company serve you in your HVAC requirements. A company like Optimum Energy could be helpful. It offers energy-saving methods of controlling the cooling equipment in large office buildings.

“Big HVAC systems have digital control systems, but they are often operated inefficiently today,” says Denis Du Bois, editor and founder of Energy Priorities magazine. “Optimum can make existing systems about 25 percent more efficient, keep comfort at the same or better levels, save water in the process, and qualify for some nice financial incentives.”

He adds that users of distributed generation consider cogen equipment to be strategic assets and Optimum Energy turns HVAC into a strategic asset, too, an asset that puts the owner in control of one of the largest areas of energy cost in a commercial building. That can mean investing less capital in cogen capacity, as well as paying lower demand charges and standby fees from the utility.

More Than Just Equipment
It’s not about a single piece or type of equipment; it’s the whole ventilation, heating, and air-conditioning environment, be it office, factory, or home. Experts at The Freeman Companies, who serve Central Texas with services that include repairs, regular maintenance, or the installation of new, energy-efficient equipment, say that the air allowed inside first needs to be conditioned. Also, the doors should be closed and the windows latched, with weather stripping around both.

An interesting point from The Freeman Companies is that it takes the energy of some 3 cubic feet, to treat or manage the temperature of every 1 cubic foot of outside air. That could be heating or cooling, of course. “They tell us to keep maintenance current,” notes Kelli Johnson, representing Freeman through EnviroMedia Social Marketing. “Have an expert come in at designated intervals, such as once every six months for a home, to inspect your space. The expert will make sure the blower section of your system is clean and operating correctly. Use a programmable thermostat to control temperature, based on certain specified times.”

Some of the skepticism in potential users or energy-efficient equipment is the result of people and companies who have promoted solutions that don’t work as promised. There was an abundance of gimmicky, non-working solutions for water purification years ago. Municipalities and counties bought the magical solutions, but found they couldn’t afford the operation, or, simply, that the vaunted solutions did not function as promised. (The promise-makers tended to go out of business.)

In the realm of HVAC, I found a company that has made a significant warranty for its work. It’s TAC, the company for whom Brandi McManus, quoted above, works. TAC has won a contract ($17.6 million) with the Chicago Public Schools for the district’s 20-story, 503,000-square-foot administration building in downtown Chicago. A turnkey “energy services performance contract” from TAC includes a chiller plant, new steam boilers, a digitally controlled building management system, and new windows. The company has guaranteed utility costs will decrease $1.25 million a year after the work is completed in 2009, or it will pay the difference. TAC is in the Schneider Electric family of companies, with more than 110,000 employees worldwide and operations in 190 countries.

OfficeMax, with more than 800 stores, decided to reduce energy costs and be environmentally responsible, by managing its energy expenditures more practically. It should also make the stores more attractive for customers. “Office Max signed a contract that transferred and capped the risk of HVAC capital and expenses, and combined that with an energy management system,” explains Paul Belair, president of Roth Bros., a national HVAC energy management provider, based in Ohio. “The result of the planning and decisions was a fully integrated maintenance and energy management program that got to the root of cost savings by making the provider fully accountable for all aspects of the energy management equation.”

Included in the program for OfficeMax were: the maintenance of store comfort (for employees and customers) within established temperature set points to save energy; monitoring of all energy management systems with Novar and Andover systems around the clock, from the provider’s operations center; HVAC preventative maintenance expense to prolong the life expectancy of the HVAC equipment and ensure that it operates at maximum efficiency; and achieving a multimillion-dollar guaranteed savings target, that will either be met or rebated to OfficeMax.

The system did not just happen. There was much homework done. Research was done by expert energy auditors who worked closely with roofing (another Roth Bros. expertise), mechanical and electrical, energy management system experts, and lighting engineers. The provider installed data loggers at two stores to create a demand consumption model, so that there would be a good understanding of OfficeMax’s consumption patterns. The provider also analyzed two years of the stores’ HVAC history and five years of their energy data. It is clear from reading such histories and reports that the best HVAC solutions do not come from a quick, simple replacement of equipment.

Individual Solutions
All of us do not work in huge office buildings. Many of us have offices that comprise of four or five rooms, and we are responsible for everything in those offices. There are almost certainly computers involved, and heating, ventilation, and air conditioning. One of the apparent anomalies I have encountered has been that one worker is sitting at a desk with a personal heater, so that he or she does not freeze in the air conditioning installed for the sake of the computers.

“That’s a very common problem in office buildings today,” Brandi McManus agrees. “Two people in offices right next to each other are provided completely different levels of comfort, so we have one in short sleeves and the other in a sweater. This leads occupants to bring in fans or space heaters, which use more energy to keep the space comfortable. Many of the offices we work in today were not designed or built for that use. They used to be warehouses, plants, mills, or something else entirely. Even if the building was designed for office space, it has been reconfigured, re-officed, and re-cubicled to become a very different space entirely. Typically, with such changes, the HVAC was never reconfigured to match the space.”

In the spaces where HVAC rules, rooms that are cooled and heated by the same equipment and monitored by the same thermostat are called zones. If we have areas that are basically for the same use, they may be zoned together—areas such as a group of offices, computer equipment rooms, or conference rooms. If we rezone our current facilities to meet their real needs, the occupants will be more comfortable and the facility will save energy.

“A simple example of that,” McManus says, “is an office that shares the same zone, or temperature control, with a computer room. The computer room must have very cool air, and the persons in the office next door are delivered the same degree of cooling (whether they like it or not). This is why a person brings in a space heater, which uses more energy to reheat the cool air. It is also common to zone offices with conference rooms or lobbies; that is also incorrect. By reconfiguring the ductwork and balancing the system to deliver a uniform airflow, occupants can be made much more comfortable with added energy efficiency.”

If one letter is neglected in HVAC it is the “V.” A couple of days ago, a young person told me he was glad they didn’t test the quality of indoor air. That made me think. I can think of several houses where it is uncomfortable to go through the front door, whether the cause of discomfort is a cigarette, dog, or inferior cooking. HVAC is all about our comfort, so the “V” is most important.

In this area, I came across a program going on in New York that intrigued and pleased me.

Air Innovations, in North Syracuse, NY, has almost 25 years of design, testing, and manufacturing of self-contained and remote-packaged cooling systems, including air conditioning units. Family-owned by professional licensed engineers, the company has built more than 10,000 systems to date. One product is HEPAIRx, a room air purifier and ventilator. Following the leadership of Larry Wetzel, Chairman of Air Innovations, HEPAIRx is undergoing clinical trials in the homes of more than 30 asthmatic children, ages five to 16, in northern New York.

The preliminary findings of the pilot study show that the product has reduced concentrations of particulate matter, volatile organic compounds, carbon monoxide, and carbon dioxide that trigger respiratory
response. The subjects, for example, are sleeping better when they use HEPAIRx at night in their bedrooms. The research is sponsored by the Syracuse Center of Excellence Office of Industry Collaboration, with monies provided by the EPA and the New York State Energy Research and Development Authority. So let’s not forget the “V” in HVAC. These health- and comfort-related considerations mean that the equipment in our energy efficient buildings must be able to provide what we need. HVAC filters are a critical part of that.

“Today’s sustainable buildings require that both energy efficiency and indoor air quality needs are met with a percentage of recirculated, conditioned air along with the introduction of fresh, outside air,” observes Jeff Granato, global business development manager for HVAC Filtration for DuPont Nonwovens. “Both air streams, laden with a variety of particulates, require high efficiency filtration to ensure optimal indoor air quality. The MERV 16 filter from DuPont combines extreme, clean air quality and low-energy usage to create a filter unique in the high-efficiency air filter category. The result is a lower cost, more energy-efficient alternative when a HEPA filter may be more than what is needed.”

“One of the things you should consider in research on energy-efficient HVAC is the type of filter used in the HVAC system,” confirms Maryna Polyakova, referring to Filtrete filters (products of 3M). “High-efficiency filters, like Filtrete filters for commercial use, have a lower energy requirement and less pressure drop. When you move resistance to air flow by even a small amount, it may help to deliver air more efficiently. This means that, on a hot summer’s day, the cool air will get into the space more quickly and there will be more of it. Less resistance means more air delivered to you. Filters have filtration efficiency qualities, can screen out particles in the air stream, as advised by the EPA, and lead to better health. Filtrete filters can help reduce the concentration of these particles captured by the filter and increase the number of particles being captured, including dust, pollen, and other common allergens.”

Not-So-Obvious Considerations
Most of us can imagine the importance of filters for HVAC efficiency, because we change our filters at home on a regular basis. It’s a simple, inexpensive, proven maintenance program for homeowners. Those who have larger HVAC systems understand the importance of maintenance, too. It is an inevitable cost (and help) for good results.

The sort of concept, of which most of us are ignorant, is the role played by drives in these systems. Bob Fesmire of ABB reminded me of this a few weeks ago. “Despite the economic advantages and significant energy savings available by using AC Variable Frequency Drives for HVAC applications, many building operators do not repair or replace drives when they fail,” Fesmire comments. “This is because the motors can continue to run through a bypass contactor. While this may be a great solution for short-term outages, continued operation in this mode quickly becomes an expensive way to operate a fan.”

Recent studies have shown that between 8% and 12% of HVAC drive systems are running in a bypass mode due to a drive fault. If 10% of your drives are in bypass mode, you may be using more than 50% too much energy in the HVAC air-handling system. Is there an affordable solution? “We have two clear choices,” Fesmire adds. “We can do nothing, and continue to lose increasing amounts of money each day as additional VFD systems periodically fail and go into bypass operation. Or, we can develop a program, which will change the way drives are proactively maintained.

“ABB recommends four simple steps to achieve this,” he says. First, you should inventory the drives in the building/complex. You may have a good in-house person to do this, or you may have to bring in an outside expert. You’ll want to know how many drives you have installed (with their make and model), and the age of the drives. How long have they been in service? What is their horsepower? What is the duty cycle of each drive? Load level and length-of-time data may not be easy to confirm, so it may be an educated guess. How many of the drives are in bypass mode? What replacement drive inventory exists? What on-hand spare parts are available?

Then, replace or repair all the drives operating in the bypass mode. This will start realizing original energy savings. Now, create or contract with an outside source for a preventative maintenance program, which will focus on the specific issues of drives, to keep them up and running. Replace your older and highly critical drives before they fail. A drive that is, for example, 10 years old or in a highly critical application, should be considered for replacement. Even with the cost of a new drive and installation, the benefits will include lower operating costs and improved client comfort. Companies have used 10-year-life-cycle costing or other financial analysis techniques to evaluate the economies for drive change-out.

Applications and Advances
One of the most impressive comments I saw about HVAC installations came from Matt Luckett of Roberts Heating, Air Conditioning, and Refrigeration. “Lennox has done a great job writing their installation instructions and engineering manuals, which allow quick reference to the needed information in the field. With the new zoning configuration capacity available on the L Connection Network software, Roberts can now offer its customers a complete energy management package that includes rooftop equipment and L Connection Network controls without the use of a third-party control system,” Luckett says.

Roberts installed a new HVAC system for Samtec Inc., manufacturer of electronic board components, with US headquarters in New Albany, IN. Samtec’s headquarters has several spaces with a wide range of functionality, including a manufacturing facility, offices, meeting rooms, and a large break room. Fresh-air ventilation was a top concern for this project.

Samtec wanted each zone to have the required fresh-air ventilation and to keep centralized control over the HVAC system, simultaneously monitoring the Liebert computer room system for alarms. The company wanted to reduce energy costs, too. The L Connection Network from Lennox was chosen to meet these requirements; it includes zoning capabilities that treat each zone differently according to its needs. The heart of this network is the Integrated Modular Controller (IMC), which serves as the unit controller for each rooftop unit. This IMC monitors and controls all aspects of each rooftop unit to maintain top performance, allows custom configuration of each unit, provides detailed diagnostic information to facilitate maintenance, and communicates with all other devices on the L Connection Network to create a cohesive (and easily managed) network.

There is a Lennox Comfort Sensor in each of the Samtec facility’s zones to monitor and control temperatures and relative humidity. Lennox says the Comfort Sensor is the only communicating zone sensor on the market today that combines carbon dioxide, humidity, and temperature sensing within a single device, to minimize installation labor and reduce wall clutter.

Storage of energy has been mentioned frequently as a good route to savings. ZBB Energy Corp. produces a zinc bromine battery. It’s a unique, proprietary 50-kWh energy module that can be sized and packaged as a fully customized, large format, energy storage system. What are the advantages of storing energy? “Our system is a means of using energy more efficiently,” observes Robert Parry, chief executive officer of ZBB Energy Corp. “For example, wind power generated at non-peak hours (such as 3 a.m.) can be wasted unless an efficient storage system like the zinc bromine battery is used to store the energy. Our battery stores such energy for later use at peak periods, typically during the following day.”

Electric utilities use the ZBB product to reduce the load on substation transformers that are working at maximum capacity during times of peak demand. Such use enables the utility to defer capital upgrades by charging the battery at night and using the stored energy during peak periods. “The primary features of the zinc bromine battery are superior energy density, depth of discharge and cycle life,” Parry notes. “It has large capacity scale [50 kilowatts] stackable to 500-kilowatt systems, and the ability to store energy from any prime mover generating source. We feel that the zinc bromine battery is the future of energy storage.”

Finally, we should reiterate that HVAC concerns the comfort and productivity of those working or relaxing inside buildings. We all want the same comfort indoors, but the outside offers a huge variety of climates in North America. “There are many places where homeowners are challenged with high humidity in the summer and extreme dryness in the winter,” comments Tim Butler, Invensys Climate Controls product manager for Thermostats. “We have created a solution to help consumers maintain comfort year-round and enjoy energy savings, too.”

Invensys introduced the 9800i series of Robertshaw programmable thermostats with singular humidity control, and now offers the 9850i series with both humidification and dehumidification control. To save energy, the systems have Energy Efficient Recovery that provides gradual recovery from setback temperatures to minimize use of auxiliary systems. The programmable and intermittent fan allows the user to set the fan and provide continuous circulation, while the intermittent fan provides hourly fan circulation.

My conclusion is that the momentum, to make our buildings both comfortable and energy-efficient, increases every month. Not only are the devices to achieve success already available, but there are new technologies that are being developed to establish HVAC as the leading sector in all sectors for progress and public satisfaction. You may have hours of homework to do, and many options to consider, but you can be assured that the success of your aims is possible and affordable. Most encouraging of all has been the commitment of most people involved in HVAC, to today’s advances and tomorrow’s attainments. 

Paul Hull writes on construction and environmental topics, for international magazines.

DE - May/June 2008