1. Reducing the Urban Heat Island Effect on Rooftops
Carla Snell
Huntington High School
Abstract
Project Description
Assessment of Project
Students were provided the design specifications with the following required components:
Roof material had to be laid flat (at first).
Materials used: tin, dark shingles, thatched straw.
Heat lamp for the sun and couldn’t be moved on ring stand-had to stay consistent.
Completed Test Results sheet for design and explanation.
Redesign had to be done to better project-tweaking is encouraged.
Assessment: redesign to be built better with cooler temperature results.
Design Sheets
The students goal is to create a roof that contributes as less as possible to the Urban Heat Island Effect (UHIE). Students constructed a rooftop out of recycled roof materials that had to keep temperatures as cool as possible. This recycled roof is designed for poverty residents to use instead of expensive materials. The students were required to collect only recycled materials, they had to test them, and collect their surface temperatures. They used an infrared thermometer (IRT) to take the temperatures every 10 minutes for 40 minutes total. After the results, they had to redesign and try to find a better solution to get the temperatures even lower after the 40 minutes.
Construct a rooftop that will keep the temperatures as low as possible and reduce the UHIE. The challenge was to build the rooftop out of recycled material only. They were to test the roof material and design the best possible way to reduce the UHIE. Three experiments were put to test but redesign and retest are requited to build a better rooftop for low economic status residents.
Constraints: Use only the collected rooftop materials (had to be waterproof to an extent), heat lamp, ring stand, moveable stand, and an IRT. The rooftop material must lay flat on the stand (at first), and every time something was added or changed, a new whole experiment must be completed from the beginning.
Temperature Log
WV NxGen Standards purpose
S.HS.ETS.1 – students will analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants.
S.HS.ETS.3 - evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics, as well as possible social, cultural, and environmental impacts.
Engineering Design Products
Project Timeline
47- minute class; M-F class periods.
Day 1- Introduction UHIE and green/cool roof techniques; Identify the problem with rooftop temperatures.
Day 2- Brainstorm and select the best possible solutions; Design ideas, Think about other options.
Day 3- Test the tin roof every 10 minutes for 40 minutes total; Record data on sheets; Record temperature differences.
Day 4- Test the dark shingle roof every 10 minutes for 40 minutes total; Record data on sheets; Record temperature differences.
Day 5- Test the straw roof every 10 minutes for 40 minutes total; Record data on sheets; Record temperature differences.
Day 6- Redesign; Retest; Record data on sheets, Record temperature differences.
Day 7- Students will compare data and come up with the best solution possible; Welcome Building and Construction teacher from Career and Technical Center to discuss new possible designs.
Evaluate/Reflect/Results
The students created a tin flat rooftop that is light gray in color. The tin roof was the surface that tested in the middle of the three. It’s temperature difference averaged 29°C.
The students created a dark shingle rooftop that is a dark gray in color. The shingled roof was the surface that tested the hottest of the three. It’s temperature difference averaged 36.5°C.
The students created a straw thatched rooftop (had a student that was skilled in sewing and sewed it together using a waterproof material for the edges) that is tan in color. The thatched roof was the surface that tested in the coolest of the three. It’s temperature difference averaged 18.8°C.
We started this assignment with discussing global warming and UHIE. Trying to explain UHIE was the most difficult for my special education students to grasp. It refers to such big scale problems, they have a hard time understanding the big picture. I wanted to break it down into something smaller and more realistic to their everyday lives. Some of my students attend the Career and Technical Center in building and carpentry. We asked teachers and staff from both schools to provide any extra roofing materials. We were provided with light colored tin and dark shingles. I really wanted three different surfaces. One of my students had built a pool shed with her grandfather and knew about straw thatching. She was on a mission and even sewed the sides to make it waterproof and more sturdy (hands-on learner). The students decided to not only test flat surfaces but tilted as well. They redesigned and tested all three surfaces tilted. Their results actually came out with cooler temperatures. Then they wanted to test the two cooler materials together. I wanted cooler results and that’s exactly what they engineered and learned. They found that the tilted tin with thatched straw was the best for a cooler/waterproof roof surface and didn’t contribute as much to UHIE.
Students tested on a flat surface first. The straw was the coolest (flat roof) with a temperature difference of 18.8°C.
They had prior knowledge of rooftop angles. Our school has a flat roof and their homes have tilted. We even discussed the pros and cons to each.
Students decided to test on a tilted surface. They found out all three tilted surfaces actually had cooler temperatures on the tilted surface. They also tested using tin and then straw over top. It was the winner with a temperature difference of 15.9°C.
Acknowledgements
Thank you to my driven students and collaborating teachers/staff at Huntington High School!
Thank you to Cabell County Career and Technical Center (Mr. Arthur) and Fairmont State University for providing the lesson ideas.