Environmental

The fan should effectively dissipate heat. The user is responsible for which batteries power the fan. Rechargeable batteries seem to be the most sustainable option. With enough sun a solar cell could power sch a tiny device. The fan should keep the user safe. The small plastic blades should never hurt or tangle anyone. It should look, sound, and feel pleasent to make other people curious about such a great fan.

Maintainability

Unfortunately, the user will not be able to service the pcb easily. We could supply parts that are easily disconnected from the pcb. The user could replace the fan and battery pack if the connectors are easy to use. A rechargeable battery pack would add significant cost to the unit. Possibly a solar cell could be used instead of batteries.

Reliability

Once we decide on the actual parts we will be using. The manufacturer will have reliable data we can use to estimate our products lifespan. Battery power will be a limiting factor. The MCU will draw a small current, but the motor could possibly draw half of an amp. This could mean only a two-hour operation before a battery change is required.

Manufacturability

The parts we will use are very easily obtained. In fact, the small electrical components and pcb boards drop off drastically in price when ordered in bulk. The pcb could be built using automation quite easily if the need arose.

The Practicum requirements must be taken into account. ● Have one or more sensors (inputs)
● Have one or more actuators (outputs)
● Have one or more processing modules which control actuators based on sensors.
● Use a two or more layer PCB
● Use 25% or more surface mount components that can be hand soldered

Usability

The fan will wait until the minimum tolerable temperature is reached, once this temperature is surpassed, the fan will adjust the airflow until it reaches its maximum output. There will be no need for the user to program the device. Possibly the MCU will be programmed before being mounted. Although, it may be easier to include a way to program the chip onboard the pcb. The use of the fan should take little explanation in order to reach the largest amount of users. To reach many people the fan should be portable and fairly inexpensive. I would estimate such a fan could sell for 10 dollars, but this is an early estimation. Many critical decisions must be made to accurately price such a product. The price will have the great effect the availability. The small size and cost should make it easy to sell at most stores. Even small stores with limited inventory could sell such an item.

Documentation

A website would be the easiest way to provide documentation. The site could also offer upgrades and replacement parts. The cost of printing a leaflet seems unfeasible and wasteful. Packaging should be kept minimal. Perhaps a recyclable cardboard box for shipping with brief instructions and pictures of whats included printed on the outside. Maybe just a single pdf could be stored on a server with other products. Anyone with computer access could download a datasheet if they were inclined.

Operational

The fan and sensor board would need to be small enough to fit inside whatever it is going to be used to cool down. If it was a computer/hardware fan it should probably be mountable so that it could be placed in multiple configurations within the PC shell. 6-8in by 6-8in should be small/large enough to fit inside most desktop PCs and laptops as well. The size of the fan blades will determine the size of the motor needed. The housing for a laptop may need to be thinner than the desktop version. Once installed the temperature sensor should constantly monitor the environment and change the speed of the fan accordingly.

Energy

The fan could be battery powered to make it portable. This would shorten its operating lifetime to 3-4 hours of constantly running before it would need fresh batteries. If the fan were not treated as an isolated component and were housed in some form of hardware then it could run off of the hardware's power supply. This would lengthen the lifetime of the product to depend on something malfunctioning such as the motor burning out, which could be thousands of hours of operation.