1 | Program Name or Ancillary Text eere.energy.gov The Parker Ranch installation in Hawaii 

### Certification for C&I Fans
6

- 4

- 20152 | Program Name or Ancillary Text eere.energy.gov 

### • Sampling requirements: Typically at least 2 units are selected at random to be tested

• Each unit is tested in accordance with the product’s test procedure

• To account for variations in materials, the manufacturing process, and tolerances when manufacturer’s are testing, manufacturers must use statistics to determine an appropriate rating range

• For example, product making representations of energy consumption:

• Determine the mean of the sample:

• Determine the upper confidence limit of the true mean divided by 1.05:

• Representations of energy consumption must be greater than or equal to the whichever is higher, the UCL or mean. 

### How to Rate a Basic Model

x � = mean n= number of samples x

i = efficiency measured per sample xx ̅ = 1 nn ∑ xx ii nn ii = 1

UCL = xx ̅ + tt 0

. 975 × ss nn U CL = upper confidence limit t 0.975 = t statistic for the 97.5% one tailed confidence interval with n

- 1 degrees of freedom s = standard deviation3 | Program Name or Ancillary Text eere.energy.gov 

### FER Representations for Com. and Industrial Fans

• For each fan model, certify FER at every operating point for which the model is going to be sold as declared by the manufacturer.

• Two methods for calculating FER at each self

- declared operating point: 1. FER = tested BHP + default motor losses + default transmission efficiency+ default controls losses

• Test two units at the given operating point and apply default values to determine FER for each unit in the sample ( FER a 

### , FER b 

### )

• Use DOE statistics to calculate the mean and UCL from FER a 

### and FER b 

### , determine allowable range for selecting a representative FER

• The representative FER for this operating point of a given fan basic model is selected from this range and certified to DOE. This same value must be used in all public representations.4 | Program Name or Ancillary Text eere.energy.gov 

### 2. Wire

- to
- air test

• Conduct a wire

- to
- air test for two units at the given operating point to determine the FER for each unit in the sample 

### ( FER c 

### , FER d 

### )

• Use DOE statistics to calculate the sample mean and UCL from FER c 

### and FER d 

### , determine allowable range for selecting a representative FER

• The representative FER for this operating point of a given fan basic model is selected from this range and certified to DOE. This same value must be used in all public representations. 

### FER Representations for C&I Fans5 | Program Name or Ancillary Text eere.energy.gov 

### Illustrative example based on current DOE method

• Example for method 1 at one operating point



### – Test two units at the given operating point and apply default values to determine FER for each unit in the sample ( FER a 

### , FER b 

### )
BHP a 

### = 5.92  add default values  FER a 

### = 7.34 BHP b 

### = 5.87  add default values  FER b 

### = 7.22

– Use DOE statistics to calculate the mean and UCL from FER a 

### and FER b 

### , determine allowable range for selecting a representative FER
xx ̅ = 1 nn ∑ xx ii = 1 2 × 7

. 34 + 7

. 22 = 7

. 28 nn ii = 1 UCL = xx ̅ + tt 0

. 975 × ss nn × 1 1

. 05 = 7.28 + 1 2

. 71 × 0

. 0 8 4 2 × 1 1

. 05 = 7

. 66 E nergy Conservation Standard ≥ R epresentative FER ≥ 7

. 66 

### FER Representations EXAMPLE6 | Program Name or Ancillary Text eere.energy.gov 

### Illustrative example based on current DOE method

• Example for method 2 at one operating point



### – Test two units at the given operating point to determine FER for each unit in the sample ( FER c 

### , FER d 

### )
FER a 

### = 7.30 FER b 

### = 7.18

– Use DOE statistics to calculate the mean and UCL from FER a 

### and FER b 

### , determine allowable range for selecting a representative FER
xx ̅ = 1 nn ∑ xx ii = 1 2 × 7

. 30 + 7

. 18 = 7

. 24 nn ii = 1 UCL = xx ̅ + tt 0

. 975 × ss nn × 1 1

. 05 = 7

. 2 4 + 1 2

. 71 × 0

. 0 8 4 2 × 1 1

. 05 = 7

. 62 E nergy Conservation Standard ≥ R epresentative FER ≥ 7

. 62 

### FER Representations for C&I Fans