Yes. All motors in the FEDS retrofit database meet current applicable EPAct and EISA efficiency standards that vary depending on parameters, such as motor horsepower, enclosure type, and speed.
No. FEDS infers parameters based on the most likely current condition of a building and its equipment. Inferences for an 1820 vintage building will reflect the typical improvements and upgrades that have occurred over time.
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).
If the building is newer than the rated life of the equipment in question, then the remaining life is equal to the difference of rated life and building age. If the building is older than the equipment's rated life, FEDS assumes that on average, equipment will be halfway through their life (but users can override this assumption and specify actual equipment vintage). Rated lives vary by equipment technology. Some examples of rated lives used in FEDS are:
envelope components (windows, insulation, etc.) – 40 years
lights – typically 25 years (Although the cost of replacing lamps and ballasts is figured into the analysis based on specific replacement intervals and hours of operation)
boilers – 40 years
furnaces – 20 years
chillers – 20 years
package AC units – 15 years
heat pumps – Air Source/15 years, Ground-Coupled/20 years
motors – 15 years
hot water heaters – electric, 12 years; gas, 10 years; distributed heat pump, 12 years; central heat pump, 15 years
While FEDS models motor energy use, demand, and interactions with the HVAC system quite well, it is not a substitute for the MotorMaster+ software. MotorMaster+ contains extensive motor management and analysis capabilities that are found in no other software program. FEDS recommends general categories and performance levels of motors based on what is currently available, but does not specify particular manufacturers or special features. It is recommended that results of motor analyses from FEDS be used in MotorMaster+ to further refine and specify motor purchase requirements.
For example, the effect of the affinity laws on fan motors can have a significant impact in degrading the efficiency of an energy-efficient motor if it has less slip than the original motor. While it is true that many energy-efficient motors run faster than their standard efficiency counterparts, there are typically energy-efficient motors available with a full-load rpm equivalent to that of the motor it is replacing. FEDS does not account for the effect of speed on energy consumption in centrifugal loads, but assumes the user can find a motor with an equivalent slip as their current motor. MotorMaster+ is an invaluable tool to help users assess the impact of speed on energy consumption and finding the right motor for a given application.
FEDS contains a built-in database of building survey data and is able to infer a number of building parameters based on the small set of required inputs provided by the user. For example, FEDS uses information such as building type, location, floor area, and vintage to determine the most likely construction type and geometry. It uses similar information along with heating fuel type and cooling equipment, to determine the most likely heating technology and ventilation system parameters for a building. All inferences enable a user to model buildings without having intimate knowledge of the detailed engineering parameters. The resulting building prototype parameter values are statistically the most likely values based on the limited set of information provided. Of course, all inferred data may be easily overwritten by simply entering (locking) a value in the user interface screens.
FEDS draws upon a number of sources to determine inferable parameter values. Major sources include national building energy consumption surveys such as the Commercial Buildings Energy Consumption, Residential Energy Consumption Survey, large end-use studies such as the End-Use Load and Consumer Assessment Program, ASHRAE handbooks, building and equipment codes and standards, and manufacturers' data and extensive building audit and evaluation experience.
A locked value, in terms of FEDS inputs, is one that the user has entered for an inferable parameter. This indicates to the model that this is a user-entered value and should not be updated (inferred). Clicking on the lock symbol can also lock a currently inferred value. When a value is locked, the lock icon will appear as a latched or closed lock. To unlock a value, simply click the icon again, changing it to an open or unlatched lock. This value will now be inferred the next time inferences are run.
The utilization factor represents the percentage of time during a particular period that the motor is operating. The load factor indicates the typical operating output of the motor as a percentage of rated output. For example, a 10-horsepower motor driving a 6-horsepower load and operating 50% of the time would have a load factor of 60% and a combined utilization/load factor of 30%.
FEDS allows the user to specify this information separately for occupied and unoccupied hours, either constant over the year, or varying from month to month. FEDS uses these values to calculate the hours of operation, and hence the consumption, and demand implications of each motor record. FEDS also calculates the heat output of the motors and its impact on the HVAC system.
Many motors in use today are oversized for the load they are driving, and some are grossly oversized. In such situations, the motor is driving a load equal to only a fraction of its rated capacity, and if too low the operating efficiency of the motor may suffer. Most importantly, when it's time to replace the motor, purchasing a motor with far excess capacity for its load will cost much more than a properly sized motor. Why spend more than necessary for the same (or even worse) level of service? FEDS understands t many motors may be over- (or under-) sized and allows the user to specify the required capacity of a motor, if known. FEDS will use the required capacity in order to select a replacement motor of the proper size and base its performance and cost calculations accordingly.
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.
Motor inference data and an extensive list of replacement motors (including performance and cost data) have been compiled from the MotorMaster+ software's extensive database of three-phase motors. MotorMaster+ was developed under the U.S. Department of Energy's Motor Challenge Program by the Washington State University Cooperative Extension Energy Program.