Abstract[edit | edit source]
The following page includes information about the creation of Team SAUCee's model 'Can You Feel the Heat Loss?' during Engineering 215: Introduction to Design, Fall 2010. The model will educate visitors of the Samoa Hostel about convection and the effects it has on heat loss in building.
Background[edit | edit source]
The Samoa Hostel, created by Danco and the Humboldt Bay Center for Sustainable Living, will be located on top of the Samoa Cookhouse. The sustainable and historic hostel that will feature innovative technologies in a common room, shown on the left, in order to educate and inspire its visitors about sustainable living.
Convective Heat Loss[edit | edit source]
Convection is the transfer of heat between a solid and a moving fluid, such as air, due to a difference in temperatures. Therefore, convective heat loss in homes is due to infiltration through cracks and leakage areas. Most leakage areas occur in roofs and ceilings, floors, and walls, yet a significant amount occurs around windows, doors, and outlets, as seen in the figure to the right. In colder environments, buildings are susceptible to a larger amounts of infiltration due to increased differences in indoor and outdoor temperatures and wind velocities, known as wind-driven infiltration. Convective heat loss causes many people to spend up to 20% more on heating and cooling bills due to excessive air exchange and resulting energy waste that occurs during the process.
Objective[edit | edit source]
Team SAUCee's objective was to create a convective heat loss model that will educate people about the effects of convective heat loss and the importance of weatherization.
Criteria[edit | edit source]
In order of significance, 'Can You Feel the Heat Loss?' needs to be:
- Educational:describes the model allowing spectators to learn by touching, feeling, and experiencing convective heat loss.
- Safe: this includes not having anything that could harm or place the audience in danger.
- Durable: consists of timelessness and the ability to withstand spectators of all ages to interact on a daily basis with the model.
- Aesthetically pleasing: aesthetics incorporates the theme that binds the insulation models and the convective heat loss models, as well as the sheik and beauty of the model.
- Cost-effective: encompasses the funds necessary to build and maintain this model, which cannot exceed $500 cumulatively.
Can You Feel the Heat Loss?[edit | edit source]
Our final project consists of a three dimensional model house mounted to a 3x3' back board. The house is split into two almost identical rooms, separated by a 3x1' piece of plywood. Each of these rooms contains a 50W heating bulb located at the top of the room to heat both rooms equally. One room is completely sealed, while the other room contains leakage areas including a moving door and room around windows. The front of the house model is sealed with a 3x2' sheet of Plexiglas with two hand slots cut out.
These two hand slots are sealed with two rubber sheets screwed into the plexiglas to create a better seal. These two hand slots allow visitors to stick a hand in each side and feel the difference temperature difference. Along with feeling the temperature difference, visitors can see the difference on a indoor/outdoor temperature sensor. Placed on one side of the house model, the sensor reads two different numbers and is labeled for which is the left side and which is the right side. From there, visitors can attempt to guess where the leakage areas are and then turn on a blacklight to visibly see leakage areas painted in blacklight paint. In order to simulate wind, an air pump is provided at the foot of the house model, as shown on the left. This air pump allows visitors to interact with the model by controlling the amount of wind infiltration entering the house model. The house model hooks onto the backboard with two hooks that attach to the "roof", this allows for easy maintenance and the house model to remain secure on the wall. On top of the roof is information on convective heat loss and how to prevent it.
Overall this model best meets our criteria. The collaboration of the following three methods of learning:
- feeling the heat
- identifying leakage areas
- controlling wind infiltration
Using three method of learning allows for the most interaction and education from the display. The model is safe, with the hand slots located at the bottom of the display to discourage heat bulb- related injuries. The materials used will last long and the cost of maintenance remains relatively low, so the display is sustainable and cost-effective; the model remained below-budget, as discussed below. After paint, miniature figurines, and Fedex-created information, the model is also aesthetically pleasing.
Cost[edit | edit source]
The total design hours spent was at 259 hours total as seen in the pie chart to the right. The most time was spent during the construction and building of the model, followed by time spent performing research necessary to formulate a solution.
|Material||Qty||Our Cost ($)||Retail ($)|
|60W Blacklight bulb||1||3.49||3.49|
|L-brackets(set of 2)||2||1.50||1.50|
|Box of tack nails||1||0.00||8.00|
|Foot Air Pump||1||2.00||10.00|
|50 W Heat Bulb||2||6.49||6.49|
|Oregon Scientific Thermostat||1||12.99||12.99|
The total cost of our design was $128.08, whereas the retail cost was approximately $192.58. The total materials list is seen to the below. We received many donations from Arcata Recycling Center, as well as free wood from around Arcata, allowing us to save approximately $65 in the construction of the model.
The cost of O&M remained relatively low, with a requirement to change light bulbs and remove collected dust. Thus the cost of O&M yearly would total at $52.47 as seen to the left.
|Item||Qty||Our Cost ($)|
|50W Heating Bulb||2||6.49 /bulb|
|60W Blacklight bulb||1||3.49 /bulb|
Testing[edit | edit source]
Testing results show the people learned more about what convective heat loss is after interacting with the educational model. While some of the people testing our model had little or no daily interaction with science, most enjoyed the experience of the feeling the convective heat loss. Overall, from testing the model our audience had a better understanding of what convective heat loss in and also the importance of limiting it.
The audience was very enthused to participate in the testing of the model. Because the model is interactive, the audience stayed entertained throughout the testing period as they were able to feel the heat loss and see the leakage areas. We educated our audience as we explained in detail how convective heat loss work as they were testing the model.
Also, after testing the model and leaving the heat lamps on for several hours, the sealed side remained warmer than the leakage side, successfully proving convective heat loss. In conclusion, from testing our model our audience was provided with educational facts about convective heat loss. Team SAUCee has put great time and effort into producing the model to allow the audience and future visitors to better their understanding of convective heat loss.
Discussion and Next Steps[edit | edit source]
'Can You Feel the Heat Loss?', along with other displays from Engr 215, Fall 2010, will be placed in the common room above the Samoa Cookhouse when the construction of the Hostel is complete. The display effectively meets the criteria by demonstrating a collaboration of educational methods to illustrate the effects of convective heat loss. The collaboration of interactive methods, feeling the heat, mimicking wind infiltration, and identifying leakage areas, will educate Samoa Hostel visitors further about the importance of weatherizing buildings. Particularly in colder environments, wind driven infiltration causes a larger amount of heat loss, and energy waste, in buildings. SAUCee anticipates that 'Can You Feel the Heat Loss?' will educate Samoa Hostel visitors about common leakage areas in buildings and influence them to consider insulating their homes. Convective heat loss causes an extensive amount of infiltration and resulting energy loss in buildings, yet can be properly avoided with insulation.
Thank You[edit | edit source]
Thank You Marty Reed, Sean Armstrong and Lonny Grafman for all the help in designing and building the model.
References[edit | edit source]
For more in depth look at the project, please read the full design document. A copy will be provided in the Samoa Hostel common room.