Presents: The Brumal Box Group Members: Alex Landry, Andrew Dobbin, Russell Fulgencio and Kirk MacDonald

The Brumal Box – Parts and Pieces A part-by-part analysis... Frame Refrigeration Unit Inner Shell Dispensing System Insulation Outer Shell

Frame - Prototype The frame of the prototype is constructed from 6” steel stud tracks and 1/16” aluminum angles. Total weight is 1.729 kg.

Frame – Production Model Sold by LifeSpace, the design pictured below allows for optimal circulation within the refrigerator as well as minimal weight.

Approximate Mass of Production Frame Individual Wire length; .2286 m Cross-section area; .000008 m2 Total length required; 40 x .2286 m = 9.144 m Density of steel; 8000 kg/m3 Volume required; (9.144 m)x(.000008 m2) Volume of wire = .000073 m3 Mass of frame = (.000073 m3)x(8000 kg/m3) Mass = .584 kg

Refrigeration Unit - Prototype The peltier device in our prototype is set to run at 72 W.

Refrigeration Unit – Production Model The size of the peltier device that will be used in our production model depends upon the cooling load.

Inner Shell - Prototype The inner shell is constructed of ½” pine wood.

Inner Shell – Production Model A majority of modern fridges have interiors made of plastic. The plastic is a mix of ABS (Acrylonitrile butadiene styrene), polyurethane and polypropylene.

Dispensing System - Prototype The dispensing system is computer operated, using a programmable Arduino board to run a single servo motor. A modified version of Arduino’s “Sweep” code is used to control the motion of the servo. This is a C++ code.

#include <Servo.h> Servo dispenser1; // define the servo int pos = 0; // variable to store the servo position void setup() { dispenser1.attach(9); // attach the servo to pin 9 } void loop() for(pos = 0; pos < 90; pos += 90) // goes from 0 degrees to 90 degrees { // in a 90 degree step dispenser1.write(pos); // tell servo to go to position in variable 'pos' delay(500); // 500 ms delay for the servo to reach the position for(pos = 90; pos>=0; pos-=90) // goes from 90 degrees to 0 degrees

Dispensing System – Production Model A single motor can be used to scoop the available can out of the frame. In keeping with the original plan of construction a launcher, our final model will require a receiver.

Cooling Load W = IV W = (6A)(12V) = 72 W B = QL/W 0.8 = QL/72 W = QH - QL QH = 14.4W

R Value Calculations QH = A(T2 – T1)/Rtotal ; A =6.31ft2 (Surface Area) 14.4 = (6.31ft2)(77 – 73)/Rtotal Rtotal = 9.20 Rtotal = Rwood1 + Rinsulator + Rwood2 Rinsulator = 9.20 – 2x(2.5) = 4.20 R value units: ft2*Fo/W Fiberglass; R = 3.7 (In use) Polyurethane; R = 6.15 (Ideal)

Insulation - Prototype The prototype uses yellow fiberglass insulation, with an R value of roughly 3.14 – 4.10.

Insulation – Production Model Polyurethane foam is the most widely used form of insulation in modern refrigerators. It is seen below being used as insulation in a house. The R-value of polyurethane foam is 6.15.

Outer Shell - Prototype The outer shell is constructed of ¾ inch pine wood.

Outer Shell – Production Model

Size Comparison – Prototype VS Production The use of wood for the inner and outer shell of the prototype adds considerable size to the Brumal Box. The combined width of the inner and outer shell of the prototype is 1.25”, and is expected to be ¼” on the production model.