Yes. FEDS now models and evaluates lighting controls, including occupancy sensors. To model existing lighting controls, the user must select the appropriate "yes" response to the "Existing lighting controls?" input and review the existing utilization factors. To infer reasonable utilization factors for the controlled lighting, specify the appropriate space type for the space where the lights exist.
FEDS will also automatically evaluate the savings potential and cost-effectiveness of lighting controls where they do not currently exist. In this scenario, select "no–evaluate occupancy sensor" and identify the most applicable space type. In this case, the "existing" utilization factors identify the portion of time that the lights are currently on, while the "with controls" utilization factors will be used by FEDS to model the impact of the occupancy sensor controls. The "number of sensors required" is used by the cost model to identify how many sensors need to be installed to control the current lighting.
Each lamp and ballast modeled within FEDS has a rated life (specified in hours) associated with it. Actual replacement intervals are calculated within the model based on the light's modeled operating hours (based on utilization factors and occupancy schedules) and rated life of each component. When a lamp or ballast fails, FEDS accounts for the cost to replace the component by figuring both materials and labor requirements. These costs are tallied over the economic study period and reported as the non-annual maintenance cost. FEDS uses the non-annual maintenance cost along with energy and capital costs in determining which fixture can best provide the required level of service at the lowest life-cycle cost.
Exterior lighting, such as security or parking lot lights can be included in FEDS by selecting the exterior fixture location. This will set the heat to space to 0 and alter the calculation of utilization factors appropriate for typical nighttime operation.
Refer to Appendix G of the FEDS User's Guide. Ex: FL 2x4 4F40T12 STD2 = a 2-foot by 4-foot fluorescent fixture, with four 40 watt T12 (1.5 inch diameter) lamps, operated by two standard magnetic ballasts (designed to operate two lamps each).
The inputs may be accessed within the operational and control technologies section of the ventilation inputs screen. A number of technology and control parameters are available for each. A two-position or continuously modulated damper is required for some of these options.
The air leakage into a building is determined from the inferred or user-specified infiltration rate. The infiltration rate is the amount of outside air entering the building during periods when the ventilation system is either not operating or not supplying outside air (i.e., times when building is not under a positive pressure).
The utilization factors for lighting represent the portion of time particular lights are on, on average, over the building set. They are expressed as a fraction of the maximum possible load (i.e., 100% of the lights are on 100% of the time) for a given time period. FEDS infers the occupied and unoccupied period utilization factors based on what is typical on average for the lighting technology and use-area type. FEDS typically assumes that some lights are on even during unoccupied times for security, safety, or cleaning staff, or simply because lights were left on. During seasonally unoccupied months and other periods defined as non-operating, utilization factors are set to 0 for all lighting records except for exit lights, which are assumed to operate constantly.
FEDS project costing algorithms account for any materials, taxes, and labor costs applicable to a given retrofit measure. Additionally, 15% contractor overhead, 10% design cost, and 6% site level supervisory, inspection and overhead factors are applied, along with any multipliers specified on the regional costs screen under the financial options. Note that many of the cost factors reflect real regional variation, including labor rates, materials cost multipliers, and sales tax rates—with differentiation driven by the specified zip code. Each of these parameters are also able to be modified by the user, if appropriate.
The non-annual maintenance cost is used by FEDS to account for costs recurring on a non-annual basis, such as incremental equipment replacements and replacing failed lamps and ballasts. For example, the present value of the non-annual maintenance cost for lighting represents the present value of the total cost (including materials and labor) to replace the burned-out lamps and ballasts of a particular lighting technology over the course of the study period (generally 25 years).
FEDS employs the same standard life-cycle costing methodology and algorithms as the building life-cycle costing computer program developed by the National Institute of Standards and Technology.
The discount rate is the factor used to adjust (discount) future sums of money into the equivalent current year dollar amount. It can also be thought of as the interest rate or hurdle rate (i.e., the rate of return required by a company for it to undertake a project). FEDS uses the real discount rate, which has the effect of inflation removed. FEDS provides the current Federal real discount rate as the default, but the user may enter any discount rate appropriate for their projects. Energy service companies performing shared energy savings contracts typically require real rates of return in the neighborhood of 10 to 20%.
The ventilation end use inputs screen contains very basic information on the ventilation motors (total capacity and efficiency). The fan motors button simply enables a user to specify more detailed motor parameters by accessing the underlying fan motor inputs screen. From here, information, such as speed, enclosure type, voltage, vintage, and number of motors can be specified. It is important to realize that if any of this information has been entered, the fan motor inputs on the main ventilation screen will be inaccessible without first deleting the more detailed inputs.
The global cost multiplier is an overall cost multiplier applied to the total project cost (including all materials, labor, taxes, overhead). It can be used to adjust all of the total project costs used in FEDS economic calculations. This could be used for such purposes as to account for special cost-impacting requirements of working at a facility with stringent security requirements or health and safety risks, or to assess the impact of varying costs on project economics.
On the bottom right of some input screens (windows, lighting, heating, cooling, hot water, and motors) is a check box labeled "replacement required". The purpose of this selection is to tell FEDS that this particular building component or technology must be replaced. Whether it has failed (for example, windows are broken, or the furnace has stopped working), or a replacement or upgrade is planned, checking this box will force a replacement to be evaluated and selected when the FEDS optimization analysis is run. If a replacement option is cost effective, FEDS will work as normal; however, if one is not, FEDS will still provide the recommendation even though it may not be otherwise cost effective. FEDS will still report the most cost-effective option and all of the standard details to help users make informed decisions. This option is also known as replace on failure economics.
The lighting use-area fixture density is the inferred fixtures per square foot and is based on typical lumen levels for different use-area types. It represents the average fixtures per square foot over the entire use-area (or building for single use-area buildings). Typically, the user will know the total number of fixtures in a use-area and can enter this and allow the software to calculate the fixtures per square foot.
FEDS project costs are based on industry averages and may not match the exact costs you will be charged. The end-use and technology multipliers are intended to enable the user to adjust for these discrepancies so that the costs used in the FEDS analyses are as close to actual as possible. The recommended approach would be to first enter any known cost data (such as, labor rates, tax rate, discount rate, etc.), and then run FEDS, generate reports, and see what types of projects are coming up. Compare the project costs to actual known costs or bids for similar projects of that type. If any of the technology costs are grossly high or low, adjust them appropriately with a technology multiplier. Rerun FEDS to see if the same technology is being selected, and make sure that the costs more closely represent what the anticipated cost to complete the project. Because of the complex nature of the FEDS cost data, this iterative multiplier approach is the best way for users to modify project costs.
No. At this time FEDS considers only fixture per fixture replacements that provide similar light output. However, the energy impact of correcting an over/under lit condition could be analyzed comparing by two consecutive FEDS baseline runs (by running without optimization).