Tinted WindowsTinted Windows
ByBy
Mark Thompson, Owen Carlson, Mark Thompson, Owen Carlson, Spencer SmithSpencer Smith
IntroductionIntroduction
Tinted windows reduce solar radiation that Tinted windows reduce solar radiation that damages car interiorsdamages car interiors
Tint also keeps cars cool during summer Tint also keeps cars cool during summer and winter monthsand winter months
Tint reduces glare while drivingTint reduces glare while driving
ProblemProblem
Calculate the heat flux reduction through Calculate the heat flux reduction through tinted windows.tinted windows.
Conduction Vs. RadiationConduction Vs. Radiation
Tinting is so thin that it is negligible in Tinting is so thin that it is negligible in reducing heat transfer into the car through reducing heat transfer into the car through the windows. the windows.
Combination of convection and conduction Combination of convection and conduction through the rest of the car is important but through the rest of the car is important but has nothing to do with tinted windowshas nothing to do with tinted windows
Reflecting radiation from the sun is what Reflecting radiation from the sun is what tinting does. tinting does.
Radiation MeasurementRadiation Measurement
A large part of the radiation is in the visible A large part of the radiation is in the visible region.region.
F( 0->.4)= 0.1240F( 0->.4)= 0.1240 F(.4->.7)= 0.3676 (visible)F(.4->.7)= 0.3676 (visible) F(.7->∞)= 0.5084F(.7->∞)= 0.5084
Because of lack of equipment we couldn’t Because of lack of equipment we couldn’t measure any of the other regionsmeasure any of the other regions
ResultsResults
Incident Light
0
10
20
30
40
50
60
70
80
11:02AM
11:20AM
11:38AM
11:56AM
12:14PM
12:32PM
12:50PM
1:08PM
1:26PM
1:44PM
2:02PM
2:20PM
2:38PM
2:56PM
Time
Lig
ht
(fo
ot
can
dle
s)
Light Outside of Tint
Light Inside of Tint
Light Outside w/o Tint
Light Inside w/o Tint
ResultsResults
Temperature Variations
-5
0
5
10
15
20
10:48 AM 11:16 AM 11:45 AM 12:14 PM 12:43 PM 1:12 PM 1:40 PM 2:09 PM 2:38 PM
Time
Tem
per
atu
re (
C)
Temp Outside
Temp Inside Tint
Temp Inside No Tint
CalculationsCalculations
Tinting reduced visible radiation about 60%Tinting reduced visible radiation about 60% Even if tinting doesn’t block radiation in any Even if tinting doesn’t block radiation in any
other regions it still accounts for about: other regions it still accounts for about: .6 x .3676 = .22 or.6 x .3676 = .22 or
22%22% of total incident solar radiation of total incident solar radiation
Most likely tinting also reduces radiation in other Most likely tinting also reduces radiation in other regions that would help reduce temperature and regions that would help reduce temperature and damage caused by solar radiation.damage caused by solar radiation.
ConclusionConclusion
Tinting reduced the amount of visible light Tinting reduced the amount of visible light in the carin the car
It also reduced the temperature in the carIt also reduced the temperature in the car Tinting can protect car interiors from Tinting can protect car interiors from
harmful lightharmful light