The Best Path To Lighting And HVACEfficiencyThere is no question that lighting and HVAC systems are the largest energy use...
concerned with the payback for the overall upgrade program? While the available level offunding can be a limiting factor, ...
of heat, or slightly more than 3,400 Btu. The higher the lighting load, the higher the load on thebuilding’s chillers.Not ...
The concept of an energy performance contract is straightforward. An outside contractor, vendoror utility pays for the ene...
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The best path to lighting and hvac efficiency

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The Best Path To Lighting And HVAC Efficiency
There is no question that lighting and HVAC systems are the largest energy users in commercial and institutional facilities. Lighting systems account for an estimated 30 percent of the electrical energy used in commercial buildings.
The building’s chiller is the single biggest user of electricity in a typical facility. Add in the heating system, and the energy used to distribute the heating and cooling to the building, and it is no surprise that most successful energy management programs have focused on lighting and HVAC.
Fortunately, facility executives have many options when it comes to conserving energy in lighting and HVAC systems. By applying new lighting technology, facility executives can cut lighting energy use by an average of 30 to 50 percent, while improving the performance of the lighting system. Lamps with electronic ballasts, lighting controls, high efficiency replacements for incandescent lamps – all are being widely used in lighting system upgrade programs.
Similar improvements are being made in the operation of HVAC systems. New technologies allow facility executives to reduce the energy use of their HVAC systems by 25 to 50 percent, without sacrificing comfort or indoor air quality. High efficiency chillers, direct digital controls, energy management systems – these and other new technologies are being widely applied in building HVAC system upgrades.
Individual Projects or an Integrated Plan?
One of the biggest questions facility executives face when looking at upgrading lighting and HVAC systems is how much should they do. Some technologies offer a fast payback. Other technologies, while reducing energy use and improving the quality of the services provided to the facility, have much longer paybacks, often two or three times longer. Should facility executives focus only on those items that offer a rapid payback, or should they only be concerned with the payback for the overall upgrade program? While the available level of funding can be a limiting factor, other factors must also be considered.
Start with the reasons why the upgrade program is being implemented. Energy conservation, while a driving factor, is not the only issue. The primary purpose of any lighting or HVAC system is to meet the needs of building occupants. When looking to upgrade existing systems, facility executives must focus on the quantity and quality of light and space conditioning needed to meet those needs. Unfortunately, limiting system upgrades to items with a quick payback usually fails to take into account occupant needs. And when occupant needs are overlooked, facility executives risk jeopardizing productivity and morale to the point where tenants may move or the energy management measures that were implemented may be defeated by the occupants.
Another problem with limiting system upgrades to components with quick paybacks is the effect it has on overall system performance. Implementing quick payback projects tends to produce a series of upgrade patches.
But simply replacing the lamps does not address the issue of how much light is actually needed in the space. If the space is overlit, additional energy could have been saved by examining the lighting requirements, changing the number of fixtures installed, using a ballast with a lower ballast factor or installing lighting controls. Similarly, the original chiller may have been oversized for normal operation. Additional savings could have been achieved by installing a smaller chiller, or two smaller chillers whose operation can be staged to match the building load, or by installing a variable speed drive on the new chiller. Even more energy could have been saved by installing a high efficiency cooling tower.
Finally, programs that are implemented in a patchwork fashion are more expensive and more disruptive to building occupants. When the entire system is upgraded, all work in a given area can be performed at the same time. When th

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The best path to lighting and hvac efficiency

  1. 1. The Best Path To Lighting And HVACEfficiencyThere is no question that lighting and HVAC systems are the largest energy users in commercial andinstitutional facilities. Lighting systems account for an estimated 30 percent of the electrical energyused in commercial buildings.The building’s chiller is the single biggest user of electricity in a typical facility. Add in theheating system, and the energy used to distribute the heating and cooling to the building, and it isno surprise that most successful energy management programs have focused on lighting andHVAC.Fortunately, facility executives have many options when it comes to conserving energy inlighting and HVAC systems. By applying new lighting technology, facility executives can cutlighting energy use by an average of 30 to 50 percent, while improving the performance of thelighting system. Lamps with electronic ballasts, lighting controls, high efficiency replacementsfor incandescent lamps – all are being widely used in lighting system upgrade programs.Similar improvements are being made in the operation of HVAC systems. New technologiesallow facility executives to reduce the energy use of their HVAC systems by 25 to 50 percent,without sacrificing comfort or indoor air quality. High efficiency chillers, direct digital controls,energy management systems – these and other new technologies are being widely applied inbuilding HVAC system upgrades.Individual Projects or an Integrated Plan?One of the biggest questions facility executives face when looking at upgrading lighting andHVAC systems is how much should they do. Some technologies offer a fast payback. Othertechnologies, while reducing energy use and improving the quality of the services provided tothe facility, have much longer paybacks, often two or three times longer. Should facilityexecutives focus only on those items that offer a rapid payback, or should they only be
  2. 2. concerned with the payback for the overall upgrade program? While the available level offunding can be a limiting factor, other factors must also be considered.Start with the reasons why the upgrade program is being implemented. Energy conservation,while a driving factor, is not the only issue. The primary purpose of any lighting or HVACsystem is to meet the needs of building occupants. When looking to upgrade existing systems,facility executives must focus on the quantity and quality of light and space conditioning neededto meet those needs. Unfortunately, limiting system upgrades to items with a quick paybackusually fails to take into account occupant needs. And when occupant needs are overlooked,facility executives risk jeopardizing productivity and morale to the point where tenants maymove or the energy management measures that were implemented may be defeated by theoccupants.Another problem with limiting system upgrades to components with quick paybacks is the effectit has on overall system performance. Implementing quick payback projects tends to produce aseries of upgrade patches.But simply replacing the lamps does not address the issue of how much light is actually neededin the space. If the space is overlit, additional energy could have been saved by examining thelighting requirements, changing the number of fixtures installed, using a ballast with a lowerballast factor or installing lighting controls. Similarly, the original chiller may have beenoversized for normal operation. Additional savings could have been achieved by installing asmaller chiller, or two smaller chillers whose operation can be staged to match the building load,or by installing a variable speed drive on the new chiller. Even more energy could have beensaved by installing a high efficiency cooling tower.Finally, programs that are implemented in a patchwork fashion are more expensive and moredisruptive to building occupants. When the entire system is upgraded, all work in a given areacan be performed at the same time. When the system upgrade is implemented as separatecomponents at different times, occupants will be disrupted and finishes disturbed each time anew project is initiated.For these reasons industry experts recommend that lighting and HVAC upgrades be implementedon a system-wide basis rather than on an individual project basis.One at a Time?The next question that the facility executive faces is how to implement the upgrade. Should thelighting system be upgraded before or after the HVAC system, or should those systems beupgraded at the same time? Again, funding may dictate how the program is implemented, but theclose interconnections between lighting and HVAC systems suggest that the best approach toupgrading is to upgrade both at the same time.The strongest interconnection between lighting and HVAC systems is energy use. Lightingsystems introduce heat into the conditioned space. For every kilowatt of energy used by thelighting system during the air conditioning season, the HVAC system must remove one kilowatt
  3. 3. of heat, or slightly more than 3,400 Btu. The higher the lighting load, the higher the load on thebuilding’s chillers.Not only does this increase the cooling energy requirement for the building, but also it increasesthe size of the chiller required to cool the building.A comprehensive lighting upgrade program will reduce the load on the building’s chiller,lowering its energy use. If the load reduction is large enough and if the HVAC system is beingupgraded at the same time, it may be possible to replace the chiller with a smaller unit, savingboth installation and operating costs.A second link between the lighting and HVAC systems is a result of the type of work that mustbe performed during the system upgrade construction. During a lighting system upgrade, ceilingsare removed and replaced, and overhead wiring is installed and connected to new wall- mountedcontrols. During an HVAC system upgrade, ceilings are removed and replaced, overheadductwork and distribution units are installed, and control wiring is run between overhead unitsand wall-mounted thermostats. If lighting and HVAC system upgrades are not performed at thesame time, many of the construction demolition and replacement tasks must be performed twice.A third interconnection is relatively new and is increasing in importance as facility executivesmove towards interoperability in building automation systems. In the past, lighting and HVACsystems were treated as independent systems despite their energy connection. Neither systemcould communicate with or share operating information with the other.New building automation system designs are replacing these independent control systems withones that are fully interoperable. In an interoperable system, conditions and control actions inone system can be shared with other components in the building automation system. Forexample, when the lighting system’s occupancy sensors determine that a space is unoccupied andturn off the lighting system, a signal can be sent to the HVAC system directing it to reduce theairflow to that space to a minimum setting.By performing the upgrades to the lighting and HVAC systems at the same time, facilityexecutives can take advantage of opportunities arising from these interconnections, opportunitiesto further improve system performance while reducing energy use. Unfortunately, whenupgraded separately, many of these opportunities are not available.Paying for UpgradesUpgrading lighting and HVAC systems generally is an expensive undertaking. While most well-designed and properly implemented system upgrades will pay for themselves through energysavings in five to eight years, depending on the scope of the upgrade, not all organizations canafford to pay for the upgrades up front. Rather than cut back the scope of the upgrade project,facility executives have the option of entering into a performance contract with an energy serviceorganization.
  4. 4. The concept of an energy performance contract is straightforward. An outside contractor, vendoror utility pays for the energy upgrade up front, and recovers its investment over a set period oftime by being paid back from the energy cost savings generated by the upgrade. There are twobasic types of energy performance contracts: guaranteed savings and shared savings.Types of ContractsThe guaranteed savings contract establishes a fixed level of energy savings from which thecontractor will be reimbursed for expenses. If the energy modifications fail to achieve thisguaranteed level of energy savings, the contractor absorbs the loss. If the level of savingsexceeds the guaranteed level, the facility keeps the difference. Guaranteed savings contracts tendto be used more on long-term, high-dollar projects when the facility executives wants tominimize risks to the facility.The shared savings contract establishes how the energy savings produced by the system upgradeswill be divided between the contractor and the facility. How the savings are split between thecontractor and facility varies from contract to contract, but most set the split at a given rate, suchas 50-50 or 30-70. Shared savings contracts are more commonly used in short-term, low-dollarprojects.Energy performance contracts offer a number of advantages. Facilities do not have to investcapital up front to implement system upgrades. Regardless of the initial cost, entire upgradeprograms can be implemented quickly. Both the guaranteed savings and the shared savingscontracts generate a positive cash flow from their initiation. Facilities do not have to carry debtas a result of the upgrade.They do, however, have their challenges. Energy performance contracts are more complex thanother contracts, particularly if the process is being bid. All will include early terminationpenalties that levy costs against the facility in the event that the contract is terminated early. Butthe biggest challenge and the biggest risk of performance contracts comes from projecting futureenergy use for the facility based on its historical use. To do this, a baseline must be established.Energy use data must be collected for a three- to five-year period and normalized to correct forsuch factors as variations in weather, area changes within the facility, changes in use of thefacility and past energy conservation efforts. Without this normalized baseline data, facilityexecutives would not be able to determine the savings that are the result of contractor’s upgrades.Finally, facility executives must carefully evaluate both the contractor and the upgrades thecontractor is proposing to perform to determine that the energy savings will not come at theexpense of a quality working environment for building occupants or the long-term health of thefacility and its systems.Julian Arhire is a Manager with DtiCorp.com – DtiCorp.com carries more than 35,000HVAC products, including industrial, commercial and residential parts and equipmentfrom Honeywell, Johnson Contols, Robertshaw, Jandy, Grundfos, Armstrong and more.

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