What is the difference between FFU rated power and actual power consumption?

When purchasing FFU, the sample usually states a rated power, such as 80W, 120W, 180W. But this number is not the same as actual power consumption. Rated power is power information under specific conditions. The actual power consumption depends on the input power of the whole machine, running time, speed gear and control method. If you simply multiply the rated power by the number of hours per year, you may overestimate or underestimate operating costs.

The following will start from the aspects of power boundary, operating status, electricity bill calculation, and selection comparison.

First confirm which boundary the power data belongs to

Power data involves several different concepts and is easily confused:

• Motor output power : the mechanical power output by the motor shaft end;

• Motor input power : the electrical power absorbed by the motor from the driver;

• Whole machine input power : The electric power absorbed by the FFU machine from the power grid, including motors, drives and control components.

The input power of the whole machine is the basis for calculating electricity bills. If the rated power on the sample only indicates the motor output power, it cannot be used directly to calculate power consumption. Drivers and control components also consume power, especially models with speed regulation, group control or sensors. The power consumption of the control part needs to be confirmed separately.

If you are not clear about the test configuration of FFU nominal air volume, you can see Is FFU's nominal air volume tested with a filter? , first confirm the test object corresponding to the sample data, and then check the power data.

Rated conditions differ from actual operating conditions

Rated power usually corresponds to specific test conditions, such as rated air volume, rated static pressure, and specific rotation speed. When the project is actually run, the operating points may be different. After the filter accumulates dust, the resistance increases, and the fan requires higher speed or higher power to maintain the air volume; if the actual air volume of the project is lower than the rated value, the power may be lower than the rated power.

Therefore, the actual power consumption should be calculated based on the input power corresponding to the project working point, rather than directly using the rated power. If you are not familiar with the pronunciation of working points, you can read Why should we look at the complete performance curve when selecting FFU? , first confirm the power and speed at the target air volume.

The running time should be accumulated according to the status.

Cleanrooms typically do not operate at full capacity throughout the day. The fan speed and power are different during working period, duty period and shutdown period. When calculating power consumption, the input power and corresponding duration of each state should be recorded separately, and then calculated cumulatively.

For example, it runs at high speed during working hours and at low speed during duty hours. The power of the two is different. If you just multiply a power rating by 24 hours, you may overestimate or underestimate actual power usage. Multiple FFUs can be combined The FFU group control system configures operation strategies according to regions and time periods to facilitate status statistics.

Electricity bill calculation requires project electricity price

After the electricity consumption is calculated, it must be combined with the project electricity price to get the electricity bill. Electricity prices may be different in different regions and at different times, and peak and valley electricity prices will also affect the total cost. The actual electricity price of the project should be used in the calculation, not a universal average.

If the project has energy-saving goals, the annual power consumption under different operating strategies can be compared, but it should be based on measured or confirmed power data and not replaced by a fixed energy-saving ratio.

Changes in power and noise after speed adjustment

Reducing the speed can usually reduce power and noise, but the cleanliness and pressure difference after speed reduction need to be verified simultaneously. If the air volume is insufficient after speed reduction, the protection effect may be affected. For relevant judgments, please refer to Is excessive FFU air volume good for cleanliness? and What are the on-site manifestations of insufficient FFU quantity?。

If the project adopts a zone duty strategy, please refer to What are the expansion conditions for using independent modules in clean systems? , unified control interfaces and operating rules in advance.

Relationship to filter resistance and operating point

Changes in filter resistance will affect fan power. When the filter is new, the resistance is low and the power may be low; when the filter accumulates dust, the resistance increases, and the fan requires higher power to maintain the air volume. If you only calculate based on the power of the new filter when selecting a model, the later electricity bill may be underestimated.

For the relationship between filter resistance and headwind speed, please refer to What will be the impact if the wind speed facing the filter is too high? . If the filter area is insufficient, the fan may require higher pressure to maintain flow. For details, please refer to How does insufficient filter area affect fan selection?。

Corresponding relationship between complete machine power and air volume and static pressure

When comparing the power of different FFUs, the comparison should be made under the same air volume and static pressure conditions. Comparing only the power rating figures may ignore operating point differences. For an FFU with a lower rated power, if the air volume at the actual working point is insufficient, multiple units may be needed to meet the demand, and the total power consumption will be higher.

For comparison methods, please refer to Why should we look at the complete performance curve when selecting FFU? , check the power, speed and noise at the same operating point.

Indirect costs related to installation and maintenance

Actual running costs include not just electricity, but also filter changes, maintenance labor and downtime arrangements. Insufficient maintenance channels will increase subsequent expenditures. This is reflected in what later expenses will be increased due to insufficient maintenance channels . There is a more detailed analysis of Electricity, consumables and maintenance costs should be included in the comparison when selecting.

If ceiling installation is involved, please refer to How does the FFU appearance size match the ceiling module? , confirm the maintenance space and disassembly and assembly paths. For local protection on the equipment side, please refer to EFU equipment side fan filter unit , the division of labor logic between the two is The division of labor between device-side EFU and room FFU is explained in detail.

Project judgment example

For a certain project, the annual electricity bill was estimated based on the rated power of the sample. After actual operation, it was found that the electricity bill was on the high side. The investigation found that the sample power was the motor output power and did not include the power consumption of the driver and control components; at the same time, the fan power increased after the filter accumulated dust. Adjustment method: Recalculate according to the input power and working point of the whole machine, and optimize the duty strategy.

Another project compared two FFUs. One had a lower rated power, but the air volume at the working point was insufficient, so the number of units needed to be increased. After comparing the total air volume and total power of the project, the other model has lower overall power consumption. Adjustment method: Re-compare after unifying the working points, and choose the solution with better total operating cost.

These two situations illustrate that: FFU rated power and actual power consumption are different, and must be comprehensively judged based on the boundaries of the entire machine, operating status, and working points.

Key points for selection and acceptance inspection

Aili industrial equipment supporting support

FFU power consumption is related to the motor, fan, driver, control method and filter resistance. It is difficult to judge the actual operating cost by looking at a rated power alone. Aili Industrial has collaborative capabilities in motors, fans and control links. It can check the changes in the input power of the whole machine under initial resistance and final resistance based on the project's working point, operating time and speed regulation strategy, and provide power data by state to help match sample parameters with actual electricity costs. Specific models can be viewed FFU clean air supply products , supporting equipment can be viewed EFU equipment end fan filter unit , filter parameters can be referred to HEPA and ULPA filters。