Evaporative CoolerTeam Members : Ahmed Al Dobouni & Majed Noor

College of Technology

Department of Mechanical Engineering Technology

MET- 497 - Senior Project, Spring 2015

Prof. Craig Engle Prof. Lash Mapa

Advisors

Table of Contents

Introduction Project Goals & Objectives Project Specifications Project Deliverables Theoretical Background Temperature and Relative

Humidity Readings Targeted Parameters Calculations

Design Project Management Schedule Risk Assessment Budget Video Testing Results Conclusion References

Introduction

With the increased demand on cooling, the need

of delivering cooling devices at affordable

prices becomes essential.

Manufacturers of cooling devices promote the

idea of using evaporative coolers in dry and hot

climates.

Project Goals & Objectives

Suitable to operate in a dry and hot climate

Design a prototype that encourages the use of environmental friendly

cooling devices

Effectively implement and apply what the design team members have

learned throughout their engineering education

Project Specifications Drops air temperature by at least 10 degrees Fahrenheit

Effectively cools a room with up to 1989 in volume

Water Reservoir can hold up to 5 gallons of water

The cost of the prototype to design and build (< $500)

Saves up to 50 to 75 % of electrical cost compared to a traditional air

conditioning unit (Air & Water, 2015)

Project Deliverables

Project Report

Complete design of an Evaporative Cooler

SolidWorks detailed drawings

Fabricate and assemble the Evaporative Cooler prototype

Test the functionality of the designed Evaporative Cooler

Risk Assessment

Theoretical Background

Ref: (Richmueller, 2012)

Theoretical Background (Cont.)

Evaporative Coolers operate based on the evaporation of water

The evaporation of water occurs without adding any external energy

The evaporative cooling process is a constant enthalpy process (Pita, 2002)

This occurs by decreasing the sensible heat and increasing the latent heat

Temperature and Relative Humidity ReadingsThese Readings are for Phoenix, Arizona

Requirements Results

Average Dry Bulb Temperature from May to

September of 2015

Month May Jun Jul Aug Sep

Reading 77.2 92.8 93.6 96.3 88.8Average 89.74 °F = 90 °F

Assumed Drop in Temperature From 10 °F to 20 °F

Wet Bulb Temperature from May to September of 2015

Month May Jun Jul Aug Sep

Reading 55.1 61.2 69.5 71.8 67.6Average 65.04 °F = 65 °F

Relative Humidity from May to September of 2015

Month May Jun July Aug Sep

Reading 25 22.5 34 38.5 36.5Average 31.3 = 31

Targeted Parameters

Ref: (Pita, 2012)

Targeted Parameters (Cont.)

Ref: (Pita, 2012)

Calculations: How Much Water The System Consumes Per Hour

Wet Bulb Depression

(F) 

Saturation Efficiency

 0.80

 0.82

 0.84

 0.86

 0.88

 0.90

 0.92

 0.94

 0.96

 0.98

 5

 0.50

 0.51

 0.52

 0.53

 0.55

 0.56

 0.57

 0.58

 0.60

 0.61

 10

 0.99

 1.02

 1.04

 1.07

 1.09

 1.12

 1.14

 1.17

 1.19

 1.22

 15

 1.49

 1.53

 1.56

 1.60

 1.64

 1.68

 1.71

 1.75

 1.79

 1.83

 20

 1.99

 2.04

 2.09

 2.14

 2.19

 2.23

 2.28

 2.33

 2.38

 2.43

 25

 2.48

 2.55

 2.61

 2.67

 2.73

 2.79

 2.86

 2.92

 2.98

 3.04

 30

 2.98

 3.05

 3.13

 3.20

 3.28

 3.35

 3.43

 3.50

 3.58

 3.65

 35

 3.48

 3.56

 3.65

 3.74

 3.82

 3.91

 4.00

 4.08

 4.17

 4.26

 40

 3.97

 4.07

 4.17

 4.27

 4.37

 4.47

 4.57

 4.67

 4.77

 4.87

WBD = DB – WB

WBD = (90 – 65) °F = 25 °F

SE =

SE = So, Water Consumption = 2.5

Ref: (Bahaita, 2012)

Calculations (Cont.): The Size of the Fan

CFM = ACH x (Pita, 2002)

ACH: 30 air changes per hour are recommended in Phoenix Arizona

V = 1989

CFM =

Calculations (Cont.):Water Cost in Phoenix Arizona

• Water cost per gallon = = $ 0.0053

• Water cost per hour = $ 0.0053 x 2.5 gallons = $ 0.013

Average Water Cost in the Summer

Water Cost per 748 gallons of water

May June July August September Average

$ 3.60 $ 4.03 $ 4.03 $ 4.03 $ 4.03 $ 4

VOLUME CHARGES per 748 Gallons (Effective March 1, 2016)Seasons Inside City Outside City

Low Season: Dec., Jan., Feb., March $3.06 $4.59Medium Season: April, May, Oct., Nov. $3.60 $5.40

High Season: June, July, Aug., Sept. $4.03 $6.05 

Ref: (City of Phoenix, 2016)

Calculations (Cont.): Hourly Total Electrical Cost

Energy (KW/hr) = Power (KW) x Time (hr)

Fan Energy (KW/hr) = 0.19 KW x 1 hour = 0.19 KW/hr

Cost to Operate the Fan (hr) = 0.19 KWh x 11.29¢/kWh = 2.15¢/hr.

Pump Energy (KW/hr) = 0.025 KW x 1 hour = 0.025 KW/hr

Cost to Operate the Pump (hr) = 0.025 KWh x 11.29¢/kWh = 0.28¢/hr

Total Electrical Cost (hr) = Fan Electrical Cost (hr) + Pump Electrical Cost (hr)

= 2.15¢/hr + 0.28¢/hr =

2.43¢/hr

Calculations (Cont.): Hourly Total Cost to Operate the System

Total Water Cost (hr) = $ 0.013

Total Electrical Cost (hr) = ¢ 2.43 x

Thus, Total Cost to Operate the System (hr) :$ 0.013 + $ 0.024 = $ 0.037

Calculations (Cont.): Average Cost to Operate an Air Conditioning Unit in Arizona

Cost to Operate the designed Evaporative Cooler per 24 hours = $0.888

Cost to Operate an air conditioning unit per 24 hours for a room with up to

2000 ft3 = $2.374

Calculations (Cont.): Cooling Media Size

The recommended design velocity of the should have a Face Velocity (FV)

of between 500 to 550 feet per minute (FPM)

The Face Velocity (FV) =

FV = 524

Thus, Area of Cooling Media =

Calculations (Cont.): Dimensions of the BoxCooling Media Face Area = 1.9

• Cooling Media length = • Tank height = 4 in x = 0.333 𝑓𝑡

• Tank Area = • Box width =

• To confirm: 1.4ft x 1.43ft x 0.333ft = 0.667

Design: Exploded View of the Assembly

Design: Back Side of the Box

Design: Dimensions of the Box

Design: 3D Side & Back View of the System

Project Management ScheduleTask Wee

k 1Week 2

Week 3

Week 4

Week 5

Week 6

Week 7

Week 8

Week 9

Week 10

Week 11

Week 12

Week 13

Week 14

Week 15

Week 16

Prepare a 3D Model on SolidWorks    Design Work and Drawings Completed      

Do the Calculations                                Decide the Water Pump                                

Design the Frame      

Design for the Mounting Holes of Fan and Pump    

Calculations Completed and Approved                                Combing and Testing the Pump Motor                  

Purchase the Fan, Insulation, and the Flow Meter                                

Fabricating and Machining of Other Parts            

Design for the Mounting Holes of Fan and Pump                                

Assembly and Testing of Parts Complete Final Testing

Final Report                                

Presentation

Risk Assessment: Risk Ranking Schedule

Highly

Likely5 10 15 20 25

Likely 4 8 12 16 20

Possible 3 6 9 12 15

Unlikely 2 4 6 8 10

Not Likely 1 2 3 4 5

  Low  Moderate Serious Major  Catastrophic 

Catastrophic 20-25

Major 16-19

Serious 11-15

Moderate 6-10

Low 1-5

Risk Range Risk Level

Risk Assessment (Cont.): Initial Risk Assessment

No. Hazard Probability (Frequency)

Impact (Severity) Risk Level Risk Range

1  Electrical Shock due water being in contact with electrical cables 5 5 25 Catastrophi

c

2 

Electric shock due to the connected electric cables not properly being

sealed with a proper electric sealant tape at the connection points

4 5 20 Catastrophic

3  Physical Injury due to the moving fan 3 4 12 Serious

4 Electrical Shock due to plugging the system’s electrical cord to an outlet

with wetted hands4 4 16 Major

5  Electrical Shock due to the pump and the fan cables being loose 3 3 9 Moderate

Risk Assessment (Cont.): The Applied Control MeasuresNo. Hazard Solution

1 Electrical Shock due water being in contact with electrical cables

Covering the electrical cables with a water proof box will reduce the

likelihood of an electrical shock to occur

2

Electric shock due to the connected electric cables not properly being sealed with a proper electric sealant tape at the

connection points

The connected electric cables at can be sealed with an electric sealant tape at the

connection points

3 Physical Injury due to the moving fanFixing a Fan Guard will assist in limiting the contact between the moving fan and

individuals

4Electrical Shock due to plugging the

system’s electrical cord to an outlet with wetted hands

Indicate in documentation to dry hands well prior to turning on the system

5 Electrical Shock due to the pump and the fan cables being loose

The electric cables can be fixed in place using electric cable ties

Risk Assessment (Cont.): Final Risk Assessment

No. Hazard Probability (Frequency)

Impact (Severity) Risk Level Risk Range

1 Electrical Shock due water being in contact with electrical cables 2 3 6 Moderate

2 

Electric shock due to the connected electric cables not properly being

sealed with a proper electric sealant tape at the connection points

3 2 6 Moderate

3  Electrical Shock due to the pump and the fan cables being loose 2 2 4 Low

4  Physical Injury due to the moving fan 2 2 4 Low

5  Electrical Shock due to Turning on the system with wetted hands 2 1 2 Low

Initial Budget

Component’s Name Quantity Vendor Part Number Individual Price Total Price

Fan 1 McMaster-Carr 2058K2 $239.31 $239.31Cooling Media

24" X 288" X 1"1 Indoor Comfort Supply 3409 $28.99 $28.99

Water Pump 1 Little Giant Outdoor Living CP3115 $68.48 $68.48

Plastic Valve 2 The Home Depot 032888076334 $2.38 $4.76

Plastic 90o Elbow Fitting 4 The Home Depot 611942038926  $0.28 $1.12

Plastic T-pipe Fitting 1 The Home Depot 611942038916 $0.54 $0.54Plastic Tubing Straps 1 The Home Depot 038561013832 $0.65 $0.65

PVC Cement/Primer Combo 1 The Home Depot 038753302485 $7.68 $7.68

0.5’’ x 1.0’ Plastic Pipe 1 The Home Depot 754826200488 $1.41 $1.41Flow Meter 1 Timers Plus P0550 $10.75 $10.75

Metal Sheets 6 Purdue University Calumet N\A $0 $0

Welding Cost 6 Purdue University Calumet N\A $0 $0

Initial Budget (Cont.)

Component’s Name Quantity Vendor Part NumberIndividual

PriceTotal Price

Screws 8 Lindy’s ACE 56 $ 0.23 $ 1.84Silicone 1 Lindy’s ACE 11961 $ 6.49 $ 6.49

Electric Switch 1 Lindy’s ACE 3531266 $ 4.49 $ 4.498 ft Power Tool Cord 1 Home Depot 756847000252 $ 9.56 $ 9.56

Teflon PTFE Thread Seal Tape 1 Home Depot 078864178500 $ 0.57 $ 0.57Garden Hose Adapter 2 Home Depot 098268624885 $ 4.80 $ 9.60

PVC Male Adapter 2 Home Depot 611942038176 $ 0.36 $ 0.72½ Cap Slip 1 Home Depot 611942038527 $ 0.38 $ 0.38

Schedule 40 PVC Reducer Bushing 2 Home Depot 611942038176 $ 0.58 $ 1.16

AMP Ring Vinyl 1 Home Depot 045686045174 $ 1.98 $ 1.98Blue Female/Male Pairs

Disconnect 1 Menards 3640399 $ 7.69 $ 7.69

Grip Fast 1/8" X 1/2" Slotted/Phillips Machine Screws 1 Menards 2338505 $ 0.82 $ 0.82

The Total Cost of the Initial Budget = $ 409

Adjusted Budget of the Project after Risk Assessment

Final Budget = Total Cost of the Initial Budget + Total Cost of the Adjusted Budget

= $ 409 + $ 24.91 = $ 436.48

Component’s Name Quantity Vendor Part Number Individual Price Total Price

Expanded Sheet (Fan Guard) 3” F Lindy’s ACE 5157961 $ 2.99 $ 8.97

Electric Tape 1 Home Depot 813848010021 $ 0.72 $ 0.72

Waterproof Electrical Box 1 Home Depot 042269006799 $ 13.97 $ 13.97

4” in Ties 1 Menards 3642627 $ 1.25 $ 1.25

The Total Cost of the Adjusted Budget = $ 24.91

Testing Results

0 5 10 15 20 25 30 35 40 45 50 55 60 65757677787980818283848586878889909192939495

Experiment Results

Temperature Changes over Time

Time (Minutes)

Tem

pera

tue

(F)

Conclusion

 Project SpecificationsTesting

Results

Met

Specifications

Didn’t Meet

Specifications

Drops air temperature by at least 10 degrees Fahrenheit 11 °F  

Effectively cools a room with up to 1989 in volume 1989  Water Reservoir can hold up to 5 gallons of water 5 gallons     

The cost of the prototype to design and build (< $500) $ 436.48    

Saves up to 50 to 75 % of electrical cost compared to a

traditional air conditioning unit $ 0.024

The Table below demonstrates the conclusion of the project

ReferencesReferences

Arizona Department of Water Resources. (2015). Residential Home Page. Retrieved on April 14,

2016 from: http://www.azwater.gov/AzDWR/StatewidePlanning/Conservation2/Resident

ial/Residential_Home2.htm

Arizona Electricity Rates & Consumption. (2016). Residential Electricity Rates & Consumption

in Arizona. Retrieved on April 15, 2016 from: http://www.electricitylocal.com/states/ariz

ona/

Air & Water. (2015). Portable Air Conditioners vs. Swamp Coolers - Which is Right for You?

Retrieved on March 10, 2016 from: http://www.air-n-water.com/Portable-AC-

SwampCooler.htm

All Systems Mechanical. (2016). How Much Does it Cost to Run an Air Conditioner? Retrieved

on April 15, 2016 from: http://asm-air.com/airconditioning/much-cost-run-air-conditioner/

Bahaita, A. (2012). Principles of Evaporative Cooling System. Retrieved on March 7, 2016

from: http://www.pdhonline.org/courses/m231/m231content.pdf

MyForecast. (2015). Almanac: Historical Information. Retrieved on September 15, 2015 from: h

ttp://www.myforecast.com/bin/climate.m?city=10899&metric=false

Nakayama, S. (2015). Risk Assessment [PDF document]. Retrieved from: https://mycourses.purd

uecal.edu/webapps/blackboard/execute/content/file?cmd=view&content_id=_5581596_1

&course_id=_196257_1

Pita, G. Edward. (2002). Finding the Infiltration Rate. Air Conditioning Principles and Systems:

An Energy Approach (4th ed., p. 9-169). Upper Saddle River, NJ: Prentice Hall

Phoenix Weather Forecast and Current Conditions. (2016). Temperature Summary (F). Retrieved

on February 2, 2016 from: http://tiggrweather.net/wxtempsummary.php