Normal/typical plug loads are accounted for (inferred) automatically within FEDS. These values can be viewed and/or changed from the miscellaneous equipment inputs in maximum detail display. The data is based on major end-use load surveys for typical plug load levels and accounts for the typical levels of equipment loads in a given use-area type. For example, for an office building this will account for typical levels of things, such as computers, printers, copiers, clocks, vending machines, coffee makers, and kitchenette equipment.
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.
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 allows a negative value for percentage of heat to the conditioned space. For example, if the equipment has a COP of 2.0 and operates with an exterior condenser, then -200 should be entered for this value and the capacity should be half the actual rated capacity. (This will result in heating an amount equivalent to 200% of the unit's consumption as being rejected outside.)
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 typical FEDS user will not have detailed information available regarding plug load levels in order to adequately model them and will need to rely on the inferred values. However, miscellaneous equipment records may be modified or added if a load is unusual or atypical of the use-area type, or has an extremely large load (or one that sees extensive use) that is above and beyond what would be considered typical. Similarly, a user may want to reduce the capacity density for some areas deemed to have a lower load density than typical for that type of space, or even delete entire records when there is no equipment in use of a given type.
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.