fan and pump cost analysis

1-800-962-3787

Special thanks to the Bonneville Power Adminstration for permitting us to distribute this tool to energy professionals worldwide,as well as Christopher B. Milan, PE, CEM Mechanical & Civil Engineer, B.P.A. for developing these calculators.

See the complete line of energy saving drives from Cerus by clicking on the photo below:

If you have any questions regarding these tools, please click to email Chris Milan at bpa.govThis, and other handy calculators can be found at http://www.cerusind.com/calculators.aspClick here for extensive analysis tools at DOE web site

VFD CALCULATORSfor Fan & Pump Applications

VFD CALCULATORSfor Fan & Pump Applications

mailto:[email protected]

http://www.cerusind.com/calculators.asp

http://www.eere.energy.gov/

Comparison of Inlet and Outlet Dampers

of 14 Bonneville Power Administration Revision No. 1

These three (3) graphs can be useful in estimating

airflow based upon damper position. Note: These

curves are representative, not precise.

These three (3) graphs can be useful in estimating

airflow based upon damper position. Note: These

curves are representative, not precise.

Comparison of Inlet and Outlet Dampers


Fan Drives Power Graphs


The power curves above are used in the energy savings analysis. Curves developed from data obtained by measuring the operating characteristics of various fan systems and from information provided in "Flow Control", a Westinghouse publication, Bulletin B-851, F/86/Rev-CMS 8121. Curves are representative, not precise,final economic analysis should be based on actual power (kW) measurements of the fan system.

0 20 40 60 80 100 1200.0

20.0

40.0

60.0

80.0

100.0

120.0

16.4 17.020.0

25.0

32.0

40.7

51.1

62.8

75.7

89.6

104.4

Eddy Current Drive Fan Flow Control

% of Design CFM

% o

f D

esig

n I

np

ut

Pow

er (

kW

)

0 20 40 60 80 100 1200.00

20.00

40.00

60.00

80.00

100.00

120.00

4.75 5.378.00

12.89

20.27

30.38

43.46

59.75

79.50

102.93

Adjustable Speed Drive Fan Flow Control

% of Design CFM or % of Full Speed RPM

% o

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(k

W)

ADJUSTABLE SPEED DRIVE ENERGY SAVINGS CALCULATOR~ Fan Applications ~


Fan Motor Information

100.00 hp85.00 %80.00 % 1-800-3543787

Power(kW) at Fan Design CFM: 70.21 KW

Facility Information

80 hrs/yr0.05 $/kwh

Existing Flow Control Method and Fan Type

1 Inlet Guide Vane, FC Fans 4 Outlet Damper, FC Fans 71 2 Inlet Guide Vane, BI & Airfoil Fans 5 Outlet Damper, BI & Airfoil Fans

3 Inlet Damper Box 6 Eddy Current Drives

Duty Cycle Power Analysis Savings Analysis

Existing System ASD System

ASD System Power (kW)

0.0% 5.0% 20.00 14.04 5.90 4.14 39.60 $ 1.98 10.0% 5.0% 20.64 14.49 4.75 3.33 44.64 $ 2.23 20.0% 10.0% 21.57 15.14 5.37 3.77 90.99 $ 4.55 30.0% 10.0% 23.32 16.37 8.00 5.62 86.03 $ 4.30 40.0% 10.0% 26.44 18.56 12.89 9.05 76.09 $ 3.80 50.0% 10.0% 31.45 22.08 20.27 14.23 62.84 $ 3.14 60.0% 10.0% 38.92 27.32 30.38 21.33 47.97 $ 2.40 70.0% 10.0% 49.36 34.66 43.46 30.51 33.18 $ 1.66 80.0% 10.0% 63.33 44.47 59.75 41.95 20.13 $ 1.01 90.0% 10.0% 81.37 57.13 79.50 55.82 10.52 $ 0.53 100.0% 10.0% 104.01 73.03 102.93 72.27 6.04 $ 0.30

Totals: 100.0% 2,584.31 2,066.29 518.03 $ 25.90

Sample Duty Cycles (these can be used as a guide if the duty cycle is not known)Sample Duty Cycle - HIGH FAN LOADING Sample Duty Cycle - LOW FAN LOADING

Summary

Energy Savings: 518.03 KWH/yr Enter Labor Cost:Cost Savings: $ 25.90 Total Cost: $ -

Enter Materials Cost: $ - Simple Payback: years

If you have any questions or comments, please email Chris Milan at the following:

More extensive analysis tools are available at the following DOE web site:

* This is an Excel 2000 file and is approximately 2.5 MB in size.

Enter Nameplate Horsepower:Enter Nameplate Efficiency: www.cerusind.com

Enter Motor Load at Fan Design CFM:

Enter Hours per year fan operates:Enter Energy Charge:

Select Flow Control andFan Type Below Click to go to the Fan Types worksheet for more information

Selection 7 allows Measured Power (kW) readings to be used in the analysis

Enter Percent of Design Capacity (CFM)

Enter Percent of

Time at this Capacity

Annual Energy Savings (Kwh/yr)

Annual Energy Cost Savings ($/yr)Existing System

Percent of Design (KW)

Do Not Enter Data

Below

Existing System Power (kW)

Percent of Design (kW)

for ASD System

Kwh/yrexisting Kwh/yrasd

This calculator was developed by Chris Milan at the Bonneville Power Administration (BPA) and is intended to be used as an estimation of potential energy savings and simple payback for ASD installations. Final economic decisions should be based upon more extensive analysis tools than what is provided here.

[email protected]://www.eere.energy.gov/industry

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Percent of Design Capacity (cfm)

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http://www.cerusind.com/


http://www.eere.energy.gov/industry

F5

The motor efficiency remains fairly constant down to approximately 50% load and then begins to decrease.

F6

Example, if 80 bhp is required at the design cfm and a 100 hp motor is installed, the motor loading is 80% at fan design cfm. One method to estimate this would be to take an Amp reading when the fan is operating at design cfm and divide this amp reading by the motor's full load amp value.

F11

This is the total hours per year the fan operates. If the fan operates 24 hours per day, 7 days per week, 8760 hrs/yr would be entered.

A22

This is the estimated percentage of the fan's design flowrate in cubic feet per minute. For example, if the fan is operating at 50% of it's design flow rate, enter .5

C22

This is the estimated percentage of the year that the fan is expected to operate at the flowrate specified in the previous column. For example, if the fan operates 25% percent of the year at the capacity stated, enter .25 Sample duty cycles are shown below. The "low load" duty cycle offers greater ASD energy savings potential than the "high load" duty cycle.

Common Fan Types


(FC) Forward-Curved Fans (BI) Backward-Inclined Fans Radial-Blade Fans Axial FansD

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Reference: "Improving Fan System Performance" Industrial Technologies and Best Practices Web Site at: http://www.oit.doe.gov

The fan blades curve in the direction of rotation. These fans are typically not as large as other fan types and structurally are not very rugged. Fan efficiencies are in the range of 55 to 65%.

The fan blades tilt back, away from the direction of rotation. The main difference between fans in this category is the shape and construction of the blades. The Backward-Inclined Flat blades tend to be more rugged and allow some particulate to pass through but these blades are not very aerodynamic and therefore are the least efficient. The Backward-Inclined Curved blades are more efficient but their orientation with the air stream can allow moisture and particulate to collect on the blades which reduces fan performance and may cause excessive vibrations. The efficiency ranges from 75 to 85%. The Backward-Inclined Airfoil blade resembles the wing of an aircraft and is the most efficient fan type with efficiencies over 90%.

These fans are typically the most rugged of all types and can range from Paddle-Wheel design to Flat Blades with corrosion resistance coatings. These fans usually operate at lower volumes but higher pressures than other fan types. The wide openings between the blades allow larger material to pass through and also minimizes vibrations when operating during conditions when the flow and pressure drops. The construction of these fans allows them to be modified to meet specific applications and to be repaired at minimum costs. Typical ranges of fan efficiencies for Flat Blades is 55 to 65% and 60 to 75% for the Radial Tip.

This fan group includes Propeller, Tubeaxial, and Vaneaxial fans. The fan blades are installed perpendicular to the air stream. The majority of these fans can be operated in reverse which allow them to supply or exhaust the air. Propeller fans generate high airflows but minimum pressure and are the least expensive and least efficient. To increase the pressure and efficiency these fans are placed inside a hollow tube to form the Tubeaxial fan. To further increase the efficiency and develop a more unified air stream, outlet vanes are installed to form the Vaneaxial fan.

The typical performance curve for a Forward Curved fan contains a dip in the static pressure curve to the left of the point of maximum static pressure. This region of the performance curve indicates that the characteristics of the air flow through the fan was not consistent. As the flow increases, the static pressure increases and decreases within this region. It is not recommended to operate the fan within this unstable region of the fan curve due to the unpredictable flow characteristics. This area is sometimes referred to as the "stall" region.

The fan performance curve for Backward Inclined fans is similar to the forward curve but typically has a smaller dip in the static pressure curve. The major difference of the backward inclined fans is the characteristics of the BHP curve. The horsepower curve does not increase to a maximum amount at maximum flow rate but instead will reach a peak and then drop off as the flow rate continues to increase to it's maximum amount. This characteristic allows the designer to select a motor size for the worst case(design) conditions and if any errors or changes occur that would increase the flow requirements, the fan will not be overloaded. This is typically referred to as a "non-overloading" power curve.

The performance curve for fans with Radial Blade wheels is typically a smooth curve showing the pressure steadily dropping from a maximum at zero flow to a minimum pressure at full flow. This characteristic allows stable operation of the fan throughout a wide range of flow(cfm) by adjusting the pressure. The corresponding BHP curve increases at a linear rate as the fan flow rate increases. The Radial Tip fan performance curve is a blend of the Backward- Inclined and Radial Blade curves. The BHP curve increases to a maximum amount at maximum flow. The Radial Tip is more efficient than the Radial Blade and therefore requires less horsepower to produce the same output.

The fan performance curve for this group of fans indicates that they are capable of providing high flow rates at lower pressures than other fan types. These fans will typically have a unique BHP curve that requires maximum power at zero flow rate. The horsepower and static pressure will increase and decrease as flow increases until finally reaching a minimum value at maximum flow rate. These variations in flow and pressure result in different flow rates at the same operating pressure, causing instability and control problems. Operating within this region should be avoided.

Due to the narrow openings between fan blades, these fans are not suited for airstreams containing particulate. These fans usually operate at low volumes and low speeds such as in residential HVAC units.

As stated above, these fans are typically "non-overloading" and this characteristic makes them a popular choice for applications were the system performance is uncertain at maximum flow rates. The inside of these blades are usually hollow to reduce their weight but the build up of moisture and particulate can lead to cavities which reduces their efficiency. The narrow openings can limit the size of particulate in the air stream they can tolerate. These fans are a good choice for installations on the clean side of the process air stream for material and dust handling systems and for forced-draft fans in boilers.

These fans are the fans of choice for moving material or air in harsh operating environments. They are used to convey everything from air filled with particulate to wood chips, rock or metal scrap

Propeller fans are common on cooling towers and inexpensive exhaust systems. Tubeaxial and Vaneaxial fans are used in HVAC exhaust applications were higher pressures and flow rates are required. All of these fans produce significant airflow noise when compared to other fans.

Inlet Vane Graphs


power curve is over loading….go 105%

6

These power curves are used in the energy savings analysis. Curves developed from data obtained by measuring the operating characteristics of various fan systems and from information provided in "Flow Control", a Westinghouse publication, Bulletin B-851, F/86/Rev-CMS 8121. Curves are representative, not precise. Final economic analysis should be based on actual power(kW) measurements of the fan system.

0 20 40 60 80 100 1200.0

20.0

40.0

60.0

80.0

100.0

120.0

50.3

56.159.8

62.2 64.0 66.069.1

73.9

81.2

91.9

106.7

Inlet Damper Box, General Curve

% of Design CFM

% o

f D

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np

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Po

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(k

W)

0 20 40 60 80 100 1200.0

20.0

40.0

60.0

80.0

100.0

120.0

20.0 20.6 21.623.3

26.4

31.5

38.9

49.4

63.3

81.4

104.0

Inlet Guide Vane Control, Forward Curve Fans

% of Design CFM

% o

f D

esig

n I

np

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Po

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(k

W)

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20.0

40.0

60.0

80.0

100.0

120.0

47.3

52.655.8 57.4 58.5 59.9

62.366.7

73.8

84.6

99.8

Inlet Guide Vane Control, BI & Airfoil Fans

% of Design CFM

% o

f D

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n I

np

ut

Po

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(k

W)

Outlet Damper Graphs


The power curves above are used in the energy savings analysis. Curves developed from data obtained by measuring the operating characteristics of various fan systems and from information provided in "Flow Control", a Westinghouse publication, Bulletin B-851, F/86/Rev-CMS 8121. Curves are representative, not precise, final economic analysis should be based on actual power(kW) measurements of the fan system.

0 20 40 60 80 100 1200.0

20.0

40.0

60.0

80.0

100.0

120.0

20.422.3

25.6

30.4

36.7

44.5

53.8

64.6

76.9

90.6

105.9

Outlet Damper Control, Forward Curve Fans

% of Design CFM

% o

f D

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np

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Pow

er (

kW

)

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10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

110.0

120.0

52.6 53.3

57.2

63.6

71.5

80.2

88.7

96.3

102.1105.2

Outlet Damper Control, Radial Blade, Backward Inclined & Airfoil Fans

% of Design CFM

% o

f D

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n I

np

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Pow

er (

kW

)

ADJUSTABLE SPEED DRIVE ENERGY SAVINGS CALCULATOR~ Fan Applications ~

of 14 Bonneville Power Administration [Revision No. 1]

Motor Information

50.00 hpEnter Nameplate Efficiency: 95.00 %

Enter Motor Load at Fan Design CFM: 90.00 %Power(KW) at Fan Design CFM: 35.34 KW


Enter Hours per year fan operates: 8760 hrs/yrEnter Energy Charge: 0.05 $/kwh

Flow Control Method and Fan Type

1 Inlet Guide Vane, FC Fans 4 Outlet Damper, FC Fans5 2 Inlet Guide Vane, BI & Airfoil Fans 5 Outlet Damper, BI & Airfoil Fans

3 Inlet Damper, General Curve 6 Eddy Current Drives 7 Measured kW



ASD System Power (KW)

25.0% 15.0% 54.90 19.40 6.42 2.27 22,511.26 $ 1,125.56 50.0% 55.0% 71.53 25.28 20.27 7.16 87,270.91 $ 4,363.55 70.0% 25.0% 88.71 31.35 43.46 15.36 35,022.55 $ 1,751.13 90.0% 5.0% 102.08 36.07 79.50 28.09 3,494.89 $ 174.74

0.00 0.00 0.00 0.00 0.00 0.00 0.00

Totals: 100.0% 231,719.64 83,420.05 148,299.60 $ 7,414.98

Sample Duty Cycles (use these as a guide if the duty cycle is not known)Sample Duty Cycle - HIGH FAN LOADING Sample Duty Cycle - LOW FAN LOADING

Summary

Energy Savings: (Note 1) 148,299.60 KWH/yr Enter Labor Cost: $ 100,000.00 Cost Savings: $ 7,414.98 Total Cost: $ 100,950.00

Enter Materials Cost: $ 950.00 Simple Payback: 13.61 years

Enter Nameplate Horsepower:

Select Flow Control andFan Type Below Click to go to the Fan Types worksheet for more information

Enter Percent of

Design Capacity

(CFM)

Enter Percent of Time at

this Capacity

Annual Energy Savings (Kwh/Yr)

Annual Energy Cost Savings ($/yr)Existing

System Percent of

Design (KW)

Do Not Enter Data

Below

Existing System Power

(KW)


for ASD System

Kwh/yrexisting Kwh/yrasd

This calculator was developed by Chris Milan at the Bonneville Power Administration (BPA) and is intended to be used as an indication of the potential energy savings and simple payback for ASD installations. If you have any questions or suggestions for improvements, please contact Chris Milan at [email protected]. More extensive analysis tools are available at: http://www.eere.energy.gov/industry.

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This Sample Input Sheet is for viewing purposes only. No values can be inputted or changed. It is included here to give the user

an idea of what types of values can be entered into either the Fan Calculator or

Pump Calculator worksheets.

This Sample Input Sheet is for viewing purposes only. No values can be inputted or changed. It is included here to give the user

an idea of what types of values can be entered into either the Fan Calculator or

Pump Calculator worksheets.

F5


F6

Example, if 80 bhp is required at the design cfm and a 100 hp motor is installed, the motor loading is 80% at fan design cfm. One method to estimate this would be to take an Amp reading when the fan is operating at design cfm and divide this amp reading by the motor's full load amp value.

A22

This is the estimated percentage of the fan's design flowrate in cubic feet per minute. 50% is entered as .5

C22

This is the estimated percentage of the year that the fan is expected to operate at the flowrate specified in the previous column. Sample duty cycles are shown below. The "low load" duty cycle offers greater ASD energy savings potential than the "high load" duty cycle.

TYPES OF AIRFLOW CONTROL


Inlet Guide Vanes andInlet Dampers

OutletDampers

Adjustable Speed-Drives

Op

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Inlet Guide Vanes are installed across the opening of the fan inlet. By opening and closing, they vary the amount of air entering the fan and change the profile of the entering airstream. As the air passes through the vanes it begins to swirl in the same rotation as the fan impeller, this pre-spinning of the air reduces the momentum that the fan blades can impact on the entering air and therefore reduces the velocity and pressure of the discharged air. As the vanes continue to close, this swirling action increases and continues to decrease the pressure and flow the fan delivers to the system. The fan horsepower is proportional to the flow and pressure, therefore the horsepower requirement also decreases. Because the inlet vane opening affects all three of these fan characteristics, a new fan performance curve is created whenever the vane position is changed. Inlet control does not affect the system curve, as vane positions change the fan performance curve rides up and down the system curve.

Outlet dampers do not change the characteristics of the entering airstream. Outlet dampers control flowrate by restricting the amount of air being discharged. This restriction allows the air flow rate to be varied the same way a discharge throttle valve adjusts the volume of flow out of a pump. The resistance of flow through the system increases as the flow(cfm) of air increases. This relationship is shown graphically by plotting the flow and corresponding resistance(pressure) to generate the system resistance curve. When the system curve and fan performance curve are shown on the same graph, the intersection of these two curves defines a unique point of operation. When the fan is installed in this particular system and operates at this flow rate, it will produce this pressure. The fan can only operate as shown by it's performance curve, for a given pressure it will provide a unique flow or vice versa.

Adjustable Speed Drives(ASDs) control the flowrate by electronically adjusting the speed of the motor driving the fan or pump. Similar to Inlet Guide Vanes, as the speed is reduced, the flowrate, pressure and horsepower requirement is reduced which results in a new performance curve for each speed setting. With ASDs, as speed is reduced the horsepower requirement is decreased according to the affinity laws within a squared to cubic relationship depending upon the amount of static pressure and how the system responds to changes in flow and pressure. A system containing static head and in which small increases in flow result in large pressure drops will have a system curve that rises steeply. By plotting this system curve and a system curve that does not rise steeply onto the same fan or pump performance curves at various speeds, one can see the following relationship. That for the same reduction in flow rate, the system curve that rises steeply will require more speed reductions to obtain this reduced flow and therefore the greater the opportunity for energy savings.

Inlet dampers can be oriented to provide the same affect as inlet guide vanes but usually are not as effective at inducing the appropriate swirl. The blades typically operate in parallel with each other. If the inlet dampers are installed too far from the fan inlet or are not oriented properly, they only serve to restrict the entering airflow.

With outlet damper control, any new operating point is achieved by adjusting the characteristics of the system curve, not the fan performance curve. For example, in order to reduce the fan flow rate, as the outlet dampers begin to close, the system's resistance(pressure) increases and shifts the system curve upward until it intersects the fan performance curve to define a new operating point of increased pressure and reduced flow.

In determining the appropriate application of an ASD, the entire system should be evaluated. For example, if the fan or pump and electric motor is oversized, further reductions in operating speed could result in significant reductions in motor efficiency as well as the efficiencies of the fan, pump. In some cases the motor can be re-sheaved to confirm energy savings and system response to reduced speeds prior to purchasing the drive.

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Inlet Dampers are usually a better choice of flow control than Outlet Dampers because when properly installed, they allow the fan horsepower to be reduced as the flow is reduced. Inlet Guide Vanes usually provide more accurate control of fan performance than Inlet Dampers. Inlet Guide Vanes are an efficient method for controlling flow rates down to approximately 70% of capacity. This would correspond to a vane position of approximately 50% closed. If the desired fan flow rate requires that the vanes be closed more than 50%, adjustable speed drives usually provide more efficient controllability by reducing the fan speed rather than continuing to restrict the fan inlet with the guide vanes.

Dampers are an efficient method of fully open/closed flow control such as exhaust air or outside air intakes. Outlet dampers are the least efficient method of variable flow control. In order for the fan to compensate for this increase in system pressure when the dampers begin to close, it has to move to the left up along the performance curve to the higher operating pressure. For the majority of fans, as you continue to restrict flow and increase pressure, the fan operates in the least efficient and unstable region of the fan performance curve. Operating at higher system pressures than necessary to reduce the flow rate not only wastes energy but increases the air leakage throughout the system. Depending upon the variation in flow rates required by the system, inlet guide vanes or adjustable speed drives may provide more energy efficient flow control.

ASDs are an excellent choice of flow control if the system allows the fan or pump to operate at reduced flow rates and loads for a significant portion of the operating time. The ASDs provide quick and accurate adjustments to flow rate and pressure as required to maintain set point. Another advantage of ASD control is their soft starting capabilities which reduces the high in-rush currents at start-up. Operating at reduced speeds can increase the equipment life, reduce vibrations and noise. For fan applications were the flow rate does not vary significantly, inlet guide vanes may be a better choice of control. ASDs are not 100% efficient, therefore operating the motor at full speed with the ASD will increase the input power due to the inefficiency of the drive. ASDs typically require that they be placed in a clean, conditioned environment which could result in high installation costs.

Reference: "Improving Fan System Performance" Industrial Technologies and Best Practices Web Site at: http://www.oit.doe.gov

Pump Drives Power Graphs


Values used in spreadsheet

These power curves are used in the energy savings analysis. Curves developed from data obtained by measuring the operating characteristics of various pumps and from information provided in "Flow Control", a Westinghouse publication, Bulletin B-851, F/86/Rev-CMS 8121. Curves are representative, not precise, final economic analysis should be based on actual power(kW) measurements of the pumping system.

10 20 30 40 50 60 70 80 90 100 1100.00

20.00

40.00

60.00

80.00

100.00

120.00

14.32 13.05 15.3021.07

30.37

43.19

59.53

79.40

102.79

ASD Pump Flow Control

% of Design Flow (gpm) or % of Full Speed(rpm)

% o

f D

esi

gn

In

pu

t P

ow

er (k

W)

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20

40

60

80

100

120

13.5113718.15707

24.92077

33.38247

43.12217

53.71987

64.75557

75.80927

86.46097

96.29067

104.87837

Mechanical Speed Pump Flow Control

% of Design Flow (gpm)

% o

f D

esi

gn

In

pu

t P

ow

er

(kW

)

0 20 40 60 80 100 1200.00

20.00

40.00

60.00

80.00

100.00

120.00

16.40 17.0419.98

25.03

32.01

40.75

51.06

62.77

75.69

89.64

104.45

Eddy Current Drive Pump Flow Control


% o

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In

pu

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ow

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W)

ADJUSTABLE SPEED DRIVE ENERGY SAVINGS CALCULATOR~ Pump Applications ~


100.00 hp95.00 %55.00 % 1-800-354378743.19 KW


4000 hrs/yr0.05 $/kwh

Existing Pump Flow Control Method

1 Throttling Valve 4 Bypass, Recirculation Valve

1 2 Eddy Current Clutch 5 Selection 5 allows Measured Power (kW) readings to be used in the analysis

3 Mechanical (Torque Converter)



0.0% 5.0% 55.21 23.85 27.45 11.85 2,398.3010.0% 5.0% 61.39 26.52 19.12 8.26 3,651.0820.0% 10.0% 67.19 29.02 14.32 6.19 9,133.2830.0% 10.0% 72.61 31.36 13.05 5.64 10,289.9440.0% 10.0% 77.65 33.54 15.30 6.61 10,772.1650.0% 10.0% 82.31 35.55 21.07 9.10 10,579.9360.0% 10.0% 86.59 37.40 30.37 13.12 9,713.2670.0% 10.0% 90.49 39.08 43.19 18.65 8,172.1480.0% 10.0% 94.01 40.60 59.53 25.71 5,956.5790.0% 10.0% 97.15 41.96 79.40 34.29 3,066.55

100.0% 10.0% 99.91 43.15 102.79 44.40 -497.91

Totals: 100.0% 142,738.45 69,503.14 73,235.31

Sample Duty Cycles (these can be used as a guide if the duty cycle is not known)Sample Duty Cycle - HIGH PUMP LOADING Sample Duty Cycle - LOW PUMP LOADING

Summary

Energy Savings: 73,235.31 KWH/yr Labor Cost: $ - Cost Savings: $ 3,661.77 Total Cost: $ -

Materials Cost: $ - Simple Payback:

If you have any questions or comments, please email Chris Milan at the following:


Enter Nameplate Horsepower:Enter Nameplate Efficiency: www.cerusind.com

Enter Motor Load at Pump Design GPM:Enter Power(KW) at Pump Design GPM:

Enter Hours per year pump operates:Enter Energy Charge:

Select Flow Control Method Below Click to go to Pump Power Graphs for additional information

Enter Percent of Design Capacity

(GPM)

Enter Percent of

Time at this Capacity

Annual Energy Savings (Kwh/yr)

Existing System


Do Not Enter Data

Below

Existing System Power

(kW)

Percent of Design (kW)

for ASD System

ASD System Power (kW)

Kwh/yr existing Kwh/yr asd


[email protected]

50 75 900

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30

40

50

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60

20

Percent of Design Capacity (gpm)

Perc

en

t o

f T

ime a

t th

is C

ap

acit

y

30 50 70 900

10

20

30

40

50

60

15

55

25

5


Per

cent of

Tim

e at

this

Cap

acity

http://www.cerusind.com/


F5


F6

Example, if 80 bhp is required at the design gpm and a 100 hp motor is installed, the motor loading is 80% at pump design gpm. One method to estimate this would be to take an Amp reading when the pump is operating at the design flowrate and divide this amp reaading by the motor's full load amp value.

F11

This is the hours per year that the pump operates. If the pump operates 24 hours per day, 7 days per week, 8760 hrs/yr would be entered.

A22

This is the estimated percentage of the pump's design flowrate in gallons per minute. For example, if the pump is operating at 50% of it's design capacity, enter .5

C22

This is the estimated percetage of the year that the pump is expected to operate at the flowrate specified in the previous column. For example, if the pump operates 30 % of the year at the capacity stated, enter .30 Sample duty cycles are shown below. The "low load" duty cycle offers greater ASD energy savings potential than the "high load" duty cycle.

ADJUSTABLE SPEED DRIVE ENERGY SAVINGS CALCULATOR~ Pump Applications ~



Existing Pump Flow Control Method

Selection 5 allows Measured Power (kW) readings to be used in the analysis

Savings Analysis

119.92182.55456.66514.50538.61529.00485.66408.61297.83153.33-24.90

$ 3,661.77

Sample Duty Cycles (these can be used as a guide if the duty cycle is not known)Sample Duty Cycle - LOW PUMP LOADING

Summary

years


Click to go to Pump Power Graphs for additional information

Annual Energy Cost Savings ($/yr)


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30 50 70 900

10

20

30

40

50

60

15

55

25

5


Per

cent of

Tim

e at

this

Cap

acity


Throttle Valve Power Graphs


The power curves above are used in the energy savings analysis. Curves developed from data obtained by measuring the operating characteristics of various pumps and from information provided in "Flow Control", a Westinghouse publication, Bulliten B-851, F/86/Rev-CMS 8121. Curves are representative, not precise, final economic analysis should be based on actual power (kW) measurements of the pumping system.

10 20 30 40 50 60 70 80 90 100 11080

85

90

95

100

105Constant Recirculation, Bypass Control


% o

f D

esig

n (k

W)

10 20 30 40 50 60 70 80 90 100 1100

25

50

75

100

125

67.19

72.61

77.65

82.3186.59

90.4994.01

97.1599.91

Throttling Valve Flow Control


% o

f D

esig

n (

kW

)

fan and pump cost analysis

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