1. Saving Battery Life on a Laptop Computer Adam Brandt Kelly Layland

2. 2 The Problem Laptops generate a lot of heat, especially when used on your lapLaptops generate a lot of heat, especially when used on your lap A pillow is often used to insulate your legsA pillow is often used to insulate your legs Determine if resting on a pillow causes a laptop to use more energy.Determine if resting on a pillow causes a laptop to use more energy. Find out what is the best way to use a laptop computer.Find out what is the best way to use a laptop computer. Objectives

3. 3 Heat Transfer Problem What is the heat flux when the laptop is rested on different materials? How does the heat flux affect the temperature of the laptop and the energy used by the laptop

4. 4 Methods Ran laptops on different surfaces until steady state temperature reachedRan laptops on different surfaces until steady state temperature reached Measured temperature at same spot on laptop for each experimental runMeasured temperature at same spot on laptop for each experimental run Tested 2 laptops and compared dataTested 2 laptops and compared data

5. 5 Results and Analysis Used thermal conductivity to calculate heat flux from laptop Lowest temperatures occurred on a table Highest temperatures and lowest heat flux occurred on a pillow Surfacet1 (C)t2 (C)t3 (C)Thickness (m)q'' (W/m^2) Table39.1 Cardboard4130.9 0.00635334.0157 Pillow53.725.3 0.088919.1676 Pillow & Cardboard47.74524 89.29134 Results from laptop 1 Surfacet1 (C)t2 (C)t3 (C)Thickness (m)q'' (W/m^2) Table40 Cardboard42.135 0.003497 Pillow4526 0.0814.25 Pillow & Cardboard44.742.825.6 133 Results from laptop 2

6. 6 Conclusions Using your laptop on a pillow is the worst optionUsing your laptop on a pillow is the worst option –significantly lowers the heat flux and increases the temperature of the laptop which could possibly cause damage to the laptop –causes the fan to run continuously which uses more energy Placing a conductive material on top of the pillow lowers the temperature and increases the heat flux through the material, but not a lotPlacing a conductive material on top of the pillow lowers the temperature and increases the heat flux through the material, but not a lot Using a laptop on a table, not on your lap, is the most energy efficientUsing a laptop on a table, not on your lap, is the most energy efficient