engineering studies

Metrics that we are using in this project:

1. Will sense heat

2. Weighs no more than 20 lbs

3. Takes no longer than 10 minutes to assemble for customer

4. Contains a kill switch set for a temperature limit

5. Will turn off when not in use

6. At least 5 temperature settings

7. Efficient insulation

Information you might need to complete part 2

Insulation efficiency

Definition/Description: One of our customer requirements was energy efficiency. One way that this can be quantified is by the insulation efficiency of the casing. More effective insulation means the heating elements need to do less work in order to keep the inside of our heater at a specific temperature. We decided, after research and discussion, to specify that the insulation needs to be at 60% (compared to theoretical) or more, ideally 70% or more

Formulas: R=(m^2*Δt)/W    E=(actual/expected)*100

We will solve for R, the measure of capacity to resist heat flow. m^2 is the area of the tested wood in meters, Δt is the difference between the heating element temperature and the outside temperature of the wood, and W is the watts of power used by the heating element. This will be our “actual” value in the efficiency equation, with a researched R value for plywood as the “expected” value.

Experiment: In order to determine R value, we will first set the heating element up so that it gets to its full temperature before the we start testing the wood. This temperature will be measured periodically so that we know when it has stabilized. Once it has stabilized, the temperature will be noted. We will place the wood onto the heating element (no direct contact, so fire risk is low), and then wait to see how much heat gets through the wood over a time period of 20 minutes. This value will be used with our earlier temperature value to determine Δt. We will then measure the wood to calculate area and determine wattage from the label on the heating element. All of these values will then be plugged into the R value equation and evaluated.

Equipment:

· Small square of plywood

· Candle warmer (heating element)

· Thermometer

Special Testing Requirements:

None

Measurements:

· Initial temperature of heating element

· Final temperature of wood

· Area of wood

Consistency:

We have determined that the nature of our measurements do not require multiple trials

Benchmarking