This project solved the car interior overheating problem faced in warm climates when vehicles are left outside for extended periods of time. The solution included a deployable sun-shade within the interior of the car, coupled with a miniaturized air-curtain to actively transfer heat out the car using its own ventilation system. Significant decreases in internal mean temperature (of up to 15 F) were observed.

1. Team Cool Car
ME 4182 Final Presentation
December 3rd, 2014
Ryan Simpson
Rachit Kansal
Rohith Desikan
Jessica Renner
Mitra Hosseini

2. Final Complete Design

3. Gantt Chart

4. ● Hot summer weather
o Cars heat up extremely quickly
o Cabin temperature can exceed 40 F
of ambient temperature
o Very dangerous due to greenhouse
effect
● Internal car cooling methods are not
effective
o Window tinting/sunshades
o Parking in shaded areas
o Cracking windows open
User Need

5. ● US 3943726 A
● US 5373703 A
● US 4813238 A
● US 4983314 A
● US 5005367 A
Competitive Products

6. ● Ideal market locations for 2 concepts:
o Regions with humidity levels ranging from 50-95%
 With relatively low rain
and/or
o Regions with average summer temperatures of 80-110ºF
 With expendable water supplies
● Other factors to consider:
o Are cars the primary mode of transportation?
o Could we adapt this for public transit? Residences?
Market

7. Stakeholder Matrix

8. Function Tree

9. Design Needs/House of Quality

10. Specification Sheet
Changes D/W Requirement Value Source
Functionality
09/16/2014 D Fast-acting 3ºC/min Team
09/16/2014 D Maximum operating ambient temperature 60ºC Team
09/16/2014 D Minimum operating ambient temperature 15ºC Team
09/16/2014 D Target surface temperature (seats, belts, dashboard, steering wheel) ~30ºC Standard
09/16/2014 W Target ambient air temperature in cabin ~30ºC Team
09/16/2014 D Minimum permissible cabin temperature after use >10ºC Team
09/16/2014 D Detachable by hand Team
Geometry
09/16/2014 D Maximum length <1.25 m Standard
09/16/2014 D Maximum width <2.00 m Standard
09/16/2014 W Low profile (height) <0.10 m Team
09/16/2014 D Lightweight <6.8 kg Standard
Cost
09/16/2014 D For consumer <$60 Customer
Discovery
Operation
09/16/2014 D Initialize and terminate automatically or by remote communication Team
09/16/2014 D Terminate upon desired cabin temp, energy use limit, OR safety shut off
criteria
Team

11. Changes
D/W
Requirement Value Source
Safety
09/16/2014 D Maximum permissible cabin temperature after product use 40ºC Team
09/16/2014 D Maximum product temperature <30ºC Standard
09/16/2014 D No sharp edges or dangerous parts Standard
09/16/2014 D Tamper-free and anti-theft integrated mechanisms Team
09/16/2014 D Withstand torque associated with vehicle speeds of up to 70 mph Team
Maintenance/Installation
09/16/2014 W Time for installation < 1 hour Team
09/16/2014 W Reversible assembly Team
09/16/2014 W Minimum number of operating cycles (Lifetime) 10,000
Materials
09/16/2014 W Preventative: Low thermal conductivity <1 W/m^2-K Team
09/16/2014 W Preventative: High specific heat >500 J/kg-K Team
09/16/2014 W Corrective: High thermal conductivity >5 W/m^2-K Team
09/16/2014 W Corrective: Low specific heat <500 J/kg-K Team

12. Morphological Chart
Function 1 2 3 4 5 6
Corrective -
Surfaces
Water Evap
(windshield
)
Ice on
windshiel
d
TEC on
surface
Air
circulation
Endothermic
reaction
turn on ac
early
Corrective -
Ambient
Water Evap
(windshield
)
air
circulation
turn on ac
early
magnetic
refrigeration
open sun-
roof/window
mist
sprayed
into air
Preventive -
Convective
insulative
surface
cover
air curtain hard canopy fluid canopy vacuum
insulation
Preventive -
Radiative
one-layer
sunshade
multi-
layer
sunshade
insulative
surface
cover
hard canopy variable
opacity
windshield
fluid
canopy
Operate in
Ta < 120
materials
with high
Tmelting
feedback
loop
insulate
battery/elect
ronics
ask user for
input
connections
not
dependent
on T
accomodate
for thermal
exp.
Self-
powered
solar
attachment
integrated
solar
panels
stirling
engine
TEC's battery
attachment
integrated
battery
Start/Stop button timer toggle
switch
app temp sensor accel
sensor

13. Morphological Chart
Function 1 2 3 4 5 6
Portability handles collapsibility lightweight retracting
shape/geom
for carrying
Lightweight
light
materials
hollow porous
minimal
parts
separate
parts
minimal
assembly
attachment
Theft/tamper
proof
inside car self-contained
physical
locks
password
lock
text msg
link to car
keys
Reversible
Installation
clip on friction joints snap fit magnetic button adhesive
Aesthetics color slim form hidden
low
profile
aerodynamic
matching
materials
UI knobs digital screen buttons app lights text msg
Acoustics
sound
dampening
sound
cancelling
minimize
vibes
minimize
moving
parts
Error
Indicators
sounds lights txt app
material
indicator
through UI
Battery Status lights gauge car's UI system UI app text/email

14. Top Ideas from Morphological Chart

15. Concept Design and Selection

16. Concept Design and Selection

17. ● Heat Transfer Modeling on MATLAB experiencing difficulties.
● Independently would need too much mass of water
Water Reservoir

18. ● Qnetrad = (αw x G) – (ε x σ x αw x Twin4)
● Qcondw = (kw x (Tw - Twin))/thickness
● Qnetconv = hfree .x (Tw - Tamb)
● Qout = Qnetrad + Qcondw + Qnetconv
● Qdot = Qout x 1.599
● mdoutloss = -Qdot/Ewater
● Masslost8hrs = mdotloss x 3600 x 8
Water Reservoir Equations

19. Air Curtain Energy Modeling: Steady State
1. Determine incoming solar radiation
1. Determine convective heat transfer in from surroundings
1. Use above to determine total heat in
1. Equate dissipated heat by air curtain to total heat in
1. Determine air curtain’s ‘h’ value
1. Determine corresponding air curtain speed

20. Steady State Equations
1. Qrad_in = G x twind x (1- (ρshade x twind))
2. Qconv_in= hfree x A x (Ts-Tamb)
3. Qin = Qrad_in+Qconv_in
4. Qdisp = Qin
5. Qdisp = hforced x A x (Twindshield-Tcabin)
6. hforced = 10.45 – v + 10 x √v

21. Results of Steady-State Model

22. 1. ‘Typical’ summer day constructed for Gradiation and Tambient
1. Loop is created to ‘move’ through typical day
1. Current Gradiation and Tambientvalues pulled
1. Calculations performed and values updated
Air Curtain Energy Modeling: Transient

23. 1. Select Gcurrent and Tambient
1. Calculate Qrad_in
1. Calculate hfree from ΔT
1. Calculate Qconv_in
1. Use ‘v’ to calculate Qdisp
1. Find (Qin-Qdisp)
1. Update Twindshield,Tshade,Tcabin using energy balances
Transient Equations

24. Results of Transient
Analysis with System
Results of Transient
Analysis without
System

25. ● “ORCA Grow Film”
● Mylar coated bubble reflector
● Aluminum
● Polyurethane
Material Selection for Radiation Shade

26. Material Reflectance Comparison

27. ● Thickness: 0.0254 mm
● Density: 43106 kg/m3
● Size: 0.88 x 1.47 m
● Cost: $7.44 for the size
o $60 for a 1.37 x 7.62 m roll
● Reflectivity: 0.92-0.95 for IR
Orca Grow Film

28. ● Includes the weight of the sunshade, springs, and cable.
Work = Density x volume x height x sin(windshield angle)
= 6.5165 J
Power = Work/time
= 2.2855 W
where the time for deployment is 10 seconds and the windshield angle is
40º.
Motor Power Analysis

29. Fan Products
12 V DC Crossflow Cooling Fans
Manufacturer Part No. Power
Draw
Dimensions (in) Weight
(lbs)
Airflow
(cfm)
Price
Stinger SGJ78 0.6 A 1.5 x 5.7 x 6 0.9 N/A $25
McMaster 2087K12 N/A 1 ⅞ x 2 x 10 ⅛ N/A 58 $81
McMaster 19665K2
1
N/A 4 3/16 x 5 ¼ x 6 N/A 230 $44
Xscorpion TF8 N/A 1.8 x 1.8 x 8.2 N/A N/A $21
PAC CF1 0.19 A 1 ¼ x 1 ¼ x 8 ½ 0.85 54 $23
Mouser QG030 0.52 A 1.87 x 1.97 x 5.83 0.56 44 $88

30. Electronics Circuit Diagram

31. Final Bill of Materials

32. 3D CAD Modeling

33. Model of Top Unit

34. Model of Fans

35. Exploded View of Top Unit

36. Model of Bottom Unit

37. Exploded Animation of the Bottom Unit

38. Control vs Sunshade
- Sunshade was 8-10 deg lower than control over the
course of the day.
Testing and Results

39. Pictures

40. Pictures

41. Pictures

42. Pictures

43. Future Plans
• Find a solution for the sunshade sagging in the
middle (e.g. keep in horizontal tension as it rolls
up).
• Create variability in design for various car and
customer styles/preferences.

44. Thank you
Questions?