Sarah's Science Fair Project
Question:
What is the effect of dust on a fan’s speed?
1. Purpose:
What is the effect of dust on a fan’s speed?
Variables: Independent – the amount of dust on the fans
Dependent: the fan speed (rotations per minute)
Controlled: all fans were tested at high speed, only ceiling fans were tested, and only indoor fans were tested
2. Hypothesis:
A fan will go slower if dust is on its blades.
3. Procedure:
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A. Materials:
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device to measure fan speed
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B. Steps:
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find dusty fan
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take picture of fan blades
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measure fan’s speed and take data
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calibrate gram scale by zeroing it out with tissue on it
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clean fan with tissue
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take picture of fan blades
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measure fan’s speed and take data
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average data
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record data
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write conclusion
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4. Data:
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Fan 1
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Fan 2
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Fan 3
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Fan 4
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Fan 5
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| Test Date |
1/17/05
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1/17/05
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1/17/05
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1/17/05
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1/17/05
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| Location |
Parker living room
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Parker parent's bedroom
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Parker mom's home office
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Mark's living room
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S. Parker's bedroom
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| Description |
aerodynamic 5-blade, 52", Windward II
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aerodynamic 5-blade, 52" Calloway II
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aerodynamic 5-blade, 52" Calloway II
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flat 5-blade, 52" Hunter
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aerodynamic 5-blade, 52" Windward II
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| Weight of Removed Dust (grams) |
0.25 g
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0.18 g
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0.12 g
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0.21 g
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0.28 g
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| Dusty Fan Speed (r.p.m.) |
147 rpm
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120 rpm
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189 rpm
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182 rpm
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160 rpm
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| Clean Fan Speed (r.p.m.) |
149 rpm
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126 rpm
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195 rpm
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188 rpm
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168 rpm
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| Change in Speed (r.p.m.) |
+2
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+6
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+6
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+6
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+8
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| % Change in Fan Flow |
1%
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5%
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3%
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3%
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5%
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| Comments |
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Faster motor
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Replacement test
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Data Continued...
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Fan 6
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Fan 7
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Fan 8
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Fan 9
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Fan 10
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| Test Date |
1/23/05
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1/23/05
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1/23/05
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1/23/05
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1/23/05
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| Location |
King's bedroom
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Sabila's sitting room
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Robert's game room
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W. Parker's bedroom
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Mark's kitchen
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| Description |
flat 4-blade, 42"
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flat 5-blade, Hunter
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flat 5-blade, 48" Hunter
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aerodynamic 5-blade, 52" Calloway
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flat 5-blade, 52"
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| Weight of Removed Dust (grams) |
0.28 g
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0.11 g
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0.35 g
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0.16 g
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0.27 g
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| Dusty Fan Speed (r.p.m.) |
206 rpm
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225 rpm
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141 rpm
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138 rpm
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165 rpm
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| Clean Fan Speed (r.p.m.) |
208 rpm
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230 rpm
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143 rpm
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145rpm
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167 rpm
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| Change in Speed (r.p.m.) |
+2
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+5
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+2
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+7
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+2
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| % Change in Fan Flow |
1%
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2%
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1%
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5%
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1%
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| Comments |
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Slightly dirty
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Replacement test
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5. Conclusion:
My hypothesis was correct: dust affects a fan’s speed in a negative way. This is important since ceiling fan speed is directly proportional to produced ceiling fan air flow. It is not clear from this sample size whether the weight of dust affects the amount of rotations per minute (r.p.m.), but it appears that the aerodynamic fan blades were more effected by the cleaning than the flat, paddle-shaped ones.
If I could do this project over, I would expand the amount of fans I tested to get more accurate results.
Summary:
My question was will dust affect a fan’s speed. I chose this questions so I could find out if cleaning my fans would help them go faster, keeping more air blowing to keep me cool in the hot Florida summer.
The first thing I did to find out if this was true or false was make a hypothesis based on my research. My hypothesis was “dust will affect fan speed in a negative way”.
The next thing I did was to actually test the fans. I first took pictures of a dusty fan’s blades, then I measured their speed. After that I zeroed the gram scale with a tissue on it. At this point, I cleaned the fan with the tissue and measured the dust’s weight. Then I took pictures of the now-clean fan before yet again testing its speed. Finally I recorded the data.
My data reflected that all 10 fans showed a rise in their speed after I had cleared the dust off their blades.
My data showed that my hypothesis was correct: dust does affect a fan’s speed.