Sample Summary

Research Questions

Ice Harvesting:

• Before the days of refrigeration, ice harvesting was a big business. Where did ice companies get their supplies of ice for summer demand? Be specific. How important was it that ice floats? How did ice companies get their ice supply to last throughout the summer and fall seasons?

Ice Shipping:

• When ice was shipped down south, how did they keep it from melting on the ships that carried it? What was the best insulation material to keep their ice from melting? Where did they get it? How was ice shipped across the country?

Before Refrigeration:

• How did average people keep things cold? What did people do before refrigeration? When was refrigeration invented? When did home mechanical refrigerators become available?

Points to Think About:

• How does ice change as it melts? Would it be best to have your ice cube surrounded by water or drained off? How can you limit the amount of conduction, convection, and radiation in your ice cube keeper?

Bibliography

Cottrell, Debra. "Natural Ice Harvesting in New England." Natural Ice Harvesting in New England. The Heart of New England, n.d. Web. 09 Apr. 2013.

Kidder, Larry. "Ice Harvest Furrow Article." Ice Harvest Furrow Article. Friends of Howell Living History Farm, Winter 2003. Web. 09 Apr. 2013.

Stastny, John. "Malcolm Rosholt Online Archives." Ice Man. Portage County Historical Society of Wisconsin, n.d. Web. 09 Apr. 2013.

Defense of Materials

The supporting structure of this ice cube keeper was a Tupperware container. This container might be good because it is thick and would help to keep heat out, however it should be not too big and not see through. The small size of the container has less space for heat and it can be kept closer to the ground where it is cooler. There is not very much room for the ice cube to move around so less friction and heat can be produced when it is moving around. The Tupperware container is opaque so the light will have a harder time getting into the ice cube through radiation. The Tupperware is be kept upside down on the floor during the testing. This will help keep the ice cube cold because the Tupperware is curved and lighter on the bottom so it will not attract as much light and if light gets to the Tupperware then it will be reflected away by the curve. The bottom of the Tupperware is tan and the top is dark green. White absorbs less heat than black and tan will absorb less heat than dark green. It is also kept out of direct light because light transfers thermal energy through radiation and that would melt the ice cube.

On the inside there are cotton balls and a plastic bag. There is some space for air. There are cotton balls to keep the heat away from the ice cube and to keep the cold from the ice cube next to the ice cube. Air pockets are trapped in cotton balls and air does not transfer heat as it is a good insulator. It keeps everything the same temperature. The cotton balls also fill up the internal space to limit the amount of air convection. There is a plastic bag to keep the ice cube in because if the cotton balls get wet they will not be good insulation anymore as they will no longer hold in the air but will now hold in water. The ice cube will only be in contact with the plastic bag and plastic is not a good conductor, limiting the conduction.

Results

SUMMARY #1

The ice cube in the first trial lasted 1 hour more than the control ice cube. It lasted for 2:31. This means that the materials chosen were successful. However, with some improvements, the keeper can last even longer. The plastic bag was removed because if the ice is sitting in the water it will melt faster because of conduction. Water is always warmer than ice because ice is frozen water. If the ice cube is in the plastic bag then it will be forced to be next to the water. If the ice cube is resting right on top of the cotton balls then the water will be absorbed by them and therefore it will not cause the ice cube to melt as fast. It will have less contact with the water than it would have had before when it was in the plastic bag.

SUMMARY #2

The ice cube in the second trial lasted over 2 1/2 hours more than the control ice cube and 1 1/2 hours longer than trial 2. This means that the change made, removing the plastic bag from the set-up helped stopped conduction of heat through the water. To improve the ice cube keeper a final time, a large yogurt container can be used instead of small Tupperware. The yogurt container is still opaque to keep out the thermal energy that is transferred through radiation and light. It now has more room for air and has the cotton ball insulation more evenly spread around the ice cube. Having the insulation more evenly spread out around the ice cube will help keep the ice cube from melting from one particular spot like the top. The same number of cotton balls will be used even though having more cotton balls would be more insulating.

Reflection

My ice cube keeper worked well. It lasted just under twice as long as the control for the first trial and just under four times as well for the second trial. I was not expecting my second ice cube to last as long as it did because I thought that the cotton balls might lose their insulating ability once they were wet. The second ice cube lasted almost twice as long as the first one did.

I learned that many different materials can prevent heat from moving around. A plastic bag will keep thermal heat in next to the ice cube and melt it through conduction or direct contact. An opaque material can limit the thermal energy transferred by radiation because thermal energy can be transferred by light and it keeps out more light.

Constants are important in technological design because technology is made to help people accomplish tasks easier. Therefore it needs to be the most productive it can be. In order for it to be the most productive it needs to be revised. In order to revise it the problem needs to be isolated so it can be changed. If more than one variable is changed at a time, then it will not be possible to see what made the difference. I showed I understood the design process because when I made changes I made one and then tested it. Then I revised Ice Cube Keeper one more time and tested that one.

BLUEPRINT(S)

Will vary...