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LAPWORKS LAPTOP
DESK THERMAL STUDY SYNOPSIS & CONCLUSIONS
At the request of LapWorks, Inc., a California Corporation,
a series of thermal studies were conducted to evaluate the
effectiveness of the Laptop Desk∞ version 2.0 as an
insulator to increase user comfort and as a heatsink to
provide cooling for a Compaq Presario 1694 laptop computer.
These studies were conducted in January and February 2002,
by a team of engineering professors from California Polytechnic
University in Pomona, California.
To measure temperatures correctly, five thermocouples were
attached to the bottom of the computer. One was placed directly
over the CPU, the hot spot on the bottom of the computer.
Seven thermocouples were attached to the bottom of the Laptop
Desk∞ itself. As before, one of the thermocouples
was placed directly over the CPU's 'hot spot' location.
Seven configurations (case studies listed below) were selected
that would best represent possible user positions and conditions.
Case study #3 was selected as the best representation of
a baseline that all measurements would be compared against
since the most common notebook use was on a desktop application.
Over a period of five weeks, the temperatures were recorded
in each of the configurations described in the above cases.
The base condition, Case #3, was established by placing
the laptop on a typical desktop surface and measuring its
bottom surface temperatures at the 5 thermocouple locations
and then calculating an average from those measurements.
Temperatures for the Laptop Desk∞ version 2.0 were
then recorded in the 7 thermocouple locations corresponding
to possible user positions. Each time the temperatures were
taken an average was calculated.
The following observations and conclusions are drawn from
the test results.
1 - The product's effectiveness as an insulator and/or
heatsink depends on the configuration chosen by the user.
For example:
- When lying in bed and working on your notebook computer,
it is recommended to put something between you and your
notebook. If you set your notebook directly onto your
bed covers, they can often block the air intakes of your
notebook and cause it to overheat. (Think of an automobile
engine overheating.) And that same heat is being passed
through the blankets to your body. If the Laptop Desk
2.0 is used as a platform for your notebook when lying
in bed, it will immediately improve ventilation for the
notebook and greatly reduce the heat that normally passes
through your bed covers.
- When
used as a lap tray, again the Laptop Desk 2.0 makes an
excellent platform and minimizes the amount of heat passed
through to the user's lap preventing hot leg. But the
amount of heat reduced from the computer averages only
8% to 10%
in this configuration.
- In the folded configuration with the Laptop Desk
2.0 set-up as a desktop stand at full extension of the
support arm, the maximum amount of heat reduction to the
computer is 15% to 20%.
The principle reason for the 15% to 20% heat reduction
is due to the chimney effect in the convection process
where the hot air rises and the cool air settles to the
bottom.
2 - In those configurations in which the Laptop Desk 2.0
is effective, it reduces body contact and computer temperatures
by providing:
- a separation between the laptop and the user's legs.
- xa larger surface area for heat transfer by natural
convection and conduction.
3 - Surface temperatures on the bottom of the computer
as high as 140• F were recorded. Skin contact temperatures
in excess of 91• F will result in a "HOT" sensation.
Click
Here to View the Laptop Desk Thermal Evaluation Study
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