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Do the motors in the FEDS retrofit database comply with the latest motor efficiency standards?

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.

How are hot water consumption values calculated?

Weekday, Saturday, and Sunday hot water consumption values are determined using typical usage rates for a given use-area type, along with the number of occupants and occupancy schedule for each day type. Values are also adjusted according to such parameters as the presence or absence of showers and high efficiency fixtures.

How come I cannot specify a loop system in use-area 2?

FEDS assumes circulating (or loop) hot water systems serve entire buildings. Specifying a loop system for use-area 1 automatically identifies that it also serves use-area 2. Loop systems that only serve use-area 2 cannot be modeled, and the loop selection box is unnecessary and is disabled.

How do I model a building used as an office that was constructed as a school?

Generally, it is best to specify the original purpose of the building as the building type, and then modify the use-area type to reflect its current use. Select building type = "Education", use-area type = "Office." The building's construction characteristics are inferred based on building type, while usage parameters (including occupancy, lighting and equipment use, and hot water demand) are based on the use-area type.

How is hot water storage capacity calculated?

Storage capacity for hot water is calculated using the building type and building's design occupancy. For distributed tank systems, values are rounded up to the next increment of typical tank capacity.

How many building sets can I have in a case?

There is effectively no limit to the number of building sets allowed in a single case if there is enough hard drive space. Currently, each building set occupies approximately 4.3 megabytes of space across all file types. Given adequate storage space, FEDS can be—and has been—used to model an entire community, city, or utility service area.

How many buildings can I have in a building set?

There is no real limit to the number of buildings that can be modeled in a building set. However, building sets are designed to model buildings that share similar characteristics. The more similar buildings are within a given building set, the more accurate the results will be.

If a building only has hot water in a pair of restrooms that comprise...?

No. If a building (or use-area) has any hot water available users should specify 100% of it is served by hot water. As long as there is hot water available in a space, occupants will utilize it even if it is not immediately accessible. The purpose of having the portion served input is to allow the FEDS user to specify entire buildings (or use-areas) within a building set that do not have any hot water. For example, for a building set consisting of 10 buildings in which two of the buildings have no hot water service, they would enter that two buildings (or 20%) for the portion of buildings in this set that have no water heating.

If I run my motors through FEDS, do I need the MotorMaster+ software?

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.

What do I do if I have a Civilian building...?

Use the building type or use-area designation that best fits regardless of which list it is on. The building set classes were grouped this way to aid in the selection of common types, but either list may be selected.

What is a 'Combined Utilization and Load Factor'?

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.

What is meant by the required motor capacity?

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.

What tank capacity does FEDS use?

For distributed tank systems, FEDS assumes commercial tanks are 80 gallons, while residential units are 50 gallons.

FEDS assumes loop (circulating) systems serve an entire building and, therefore, the number of tanks is inferred to be one for each building, regardless of the number of use areas present.

Where does FEDS get its motor data?

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.

Question Topic

    • Heating/Cooling (11)
    • Reports (9)
    • Using FEDS (9)
    • Economic Analysis (8)
    • Fuel Types & Energy Prices (8)
    • Lighting (7)
    • Inferences (General) (5)
    • (-) Motors (5)
    • Occupancy (5)
    • Prototype Building/Geometry (5)
    • (-) Service Hot Water (5)
    • (-) Building Sets (4)
    • Weather Data (4)
    • Miscellaneous Equipment (3)
    • Ventilation (3)

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