By Kelly Charley
The purpose of this scientific research was to build a solar Hogan and discover which section of the Hogan and which solar panel design will generate the greatest temperature inside the Hogan using water and antifreeze mediums. The hypothesis was if different designs of solar panels are placed on different sections of a Hogan model using water and antifreeze mediums, then the solar panels with snake design, in Southwest Section will generate the greatest temperature inside the Hogan These researches started by first constructing a model Hogan. A solar panel was built to place on the Hogan roof. After building the heat exchanger polytubing was strung through the Hogan, solar panel and heat exchanger to transfer heat through the mediums, water and antifreeze. Temperature was measured inside and outside the Hogan. Section 2 of the solar panel is most effective in producing heat. The data showed that the snake design had superior heat generation. In this investigation, the aim was to assess the temperature effects on the Hogan when the panel is repositioned. The most significant findings to emerge from this study are the realization of various concepts already applied to current inventions. The results support the hypothesis.
1. Which solar panel design will generate the greatest temperature inside the Hogan using water and antifreeze mediums? a. Control-No solar panel b. Solar snake design c. Solar Coil design 2. In what section of the Solar Hogan will generate the greatest temperature? a. South Section b. Southwest Section
If different designs of solar panels are placed on different sections of a Hogan model using water and antifreeze mediums, then the solar panels with snake design, in Southwest Section will generate the greatest temperature inside the Hogan.
Hogan: a multi-sided house Traditional Navajo home Hogan comes from the Navajo word hoo-ghan Early Navajo Hoganso Conical forked-pole Hogan o Four sided leaning Hogan o Corbeled log Hogan Interior walls haveo Studs that support the house o Vertical 2 x 4s o Plates- horizontally placed studs o Corner post- studs placed in corners
Photos Taken By Kelly Charley
Solar energy- renewable energy source from the sun Virtually all energy on Earth is solar energy Passive or Active Passive Solar- heating and cooling of a home without the use of mechanical equipment Manipulates- shape, composition, orientation, and management Active Solar- heating and cooling using mechanical equipment Radiant floor heating- wall to wall radiator that is snaked across subfloor Water heaters commonly used to heat homes o Storage or tank o Heat pump o Tank-less coil o Solar water heater
Photo Taken By Kelly Charley Photo From: https://www.youtube.com /playlist?list =PLiZ4JIqCg23yQAcNfXEUs6hpsYnQ60tUb Photo From www.shamrockplumbing.net/radiantfloor-heating/ Photo From http://www.hiwtc.com/products/ industrial-radiator-6928-21357. htm
Solar Water heaters- a system in which water or heat collection fluid is heated in solar collectors then circulated through a heat exchanger o ICS integral Collector Storage/ Batch heater o Drain-back systems o Closed-loop antifreeze systems Heat convection- mass motion of a fluid when the heated fluid is caused to move away from the source of heat Thermal Mass- heating heat absorbent materials Heat Exchange- a unit of operation involving the heating and cooling of a single fluid or two fluids with or without a change of state Heat exchanger- a device that transfers heat from one medium or system to another Heat exchangers are more effective when the medium is in small quantities
Photos Taken By Kelly Charley
1. Construct Hogan A. Cut out octagonal base from plywood sheet B. Attach dowels to octagon base C. Cut 8 walls from plywood D. Fasten walls to dowels (glue maybe used between walls) E. Cut out 8 isosceles triangles F. Place beam in center of Hogan G. Place triangles on beam, secure with tape H. Glue triangles together then remove tape and beam. I. Use Cylinder shaped with middle carved out to attach to peak of roof. J. Cut dowels in increments that will be nailed to roof at triangle side intersection. K. Cut insulation to fit walls, floor and roof. L. Glue insulation to walls, floor and roof. M. Apply foam tape where walls and roof meet. N. Drill two exit holes in one side of Hogan. 2. Construct solar panel A. Cut 4 rectangles two A. Use dowel at corners to nail sides together B. Drill two holes on one of the shorter sides. C. Run about 25ft of poly tubing inside solar panel leaving about 1ft to exit through each drilled hole. D. Use tape to secure tubing. 3. Build and install hot water system. A. Run poly tubing inside Hogan in wave design over floor insulation. B. Inside foam cup coil about 2ft of poly tubing. (foam cup will serve as heat exchanger) C. Loop separate link of poly tubing inside cup in the middle of coil. D. Fill empty space in heat exchanger with sand. E. Cut larger tubing in 4 1 in links. F. Use links to connect poly tubing, loop to Hogan, and solar panel to heat exchanger) 4. Place solar panel on roof for Trial 1 5. Place sand in two separate containers. 6. Set one container outside the Hogan and the other one inside the Hogan. 7. Measure indoor and outdoor temperature of the sand at various designated times. 8. Repeat steps 5 and 6 for all trials
Photos Taken By Kelly Charley
Independent Variables Solar Panel Designs a. No Solar Panel - Control b. Solar Panel Snake Design c. Solar Panel Coil Design Dependent Variables Input Temperature (Inside Hogan) Output Temperature ( Outside Hogan)
Plywood (4ft x 8ft x 0.25in) Water Antifreeze Foam tape Nails 0.75 x 0.75 Square dowels 50ft 0.25in poly tubing Black tape Styrofoam insulation (4ft x 8ft) Wire Double sided tape Super glue 1ft 0.25in tubing 2 9oz Styrofoam cups Sand Thermometer Compass
Photos Taken By Kelly Charley
Table 1 Temperature of the Hogan at Various Times of Day Control Temperature in Celsius 1. Indoor Day 5:00 AM 6:00 AM 8:00 AM 12:00 PM 4:00 PM 6:00 PM 9:00 PM Section 2 1-4.1-3.5-1.5 18.8 19.2 13.5 4.4 2 1.6 2.3 3.2 14.5 11.5 6.7 2.6 Average -1.25-0.6 0.85 16.65 15.3 5 10.1 3.5 2. Outdoor Section 2 1-7 -5.6 0.7 27.2 24.2 12.1 0 2 1.2 1.8 3.5 18.5 10 5 0.8 Average -2.9-1.9 2.1 22.8 17.1 8.55 0.4 Table 2 Control (Indoor Temperature vs. Outdoor Temperature) Temperature in Celsius Time 5:00 6:00 8:00 12:00 4:00 6:00 9:00 PM AM AM AM PM PM PM Indoor -1.25-0.6 0.85 16.65 15.35 10.1 3.5 Outdoor -2.9-1.9 2.1 22.85 17.1 8.55 0.4
Table 3 Indoor Temperature with Coil Design Temperature in Celsius Time 5am 6am 8am 12am 4pm 6pm 9pm South -7.9-9.5-7.1 7.9 n/a 0.5 0.5 South -2.5-3 -1 14.4 12.3 4.3-2.4 West West -6.3-7.6-1.7 5.5 10.9 2.3 0.6 Table 4 Outdoor Temperature With Coil Design Temperature in Celsius Time 5am 6am 8am 12am 4pm 6pm 9pm South -10.9-11.5-7.9 19.9 n/a -0.5-9.9 Southwest 3.2 0.6-2.3 15.7 20.2 5.3-4.7 West -5.7-5.6-4.8 19.1 12.5 5.3-3
Table 5 Temperature of the Hogan a Various Times of Day Snaked Temperature in Celsius 1. Indoor Day 5:00 AM 6:00 AM 8:00 AM 12:00 PM 4:00 PM 6:00 PM 9:00 PM Section 2 1-1 -3.7-2.5 17.9 10.7 14.7 3.3 2-2 -2.7-2 18 19.5 13.9 3.4 Average -1.5-3.2-2.25 17.95 15.1 14.3 3.35 2. Outdoor Section 2 1-3 -5.7-0.8 34.6 17.2 11.8 0 2-3.1-4.4-0.6 34.4 26.1 12.6-0.3 Average -3.05-5.05-0.7 34.5 21.65 12.2-0.15 Table 6 Average Outdoor Subtracted by Average Indoor Temperature in Celsius 5:00 AM 6:00 AM 8:00 AM 12:00 PM 4:00 PM 6:00 PM 9:00 PM Control -1.65-1.3 1.25 6.2 1.75-1.55-3.1 Snaked -1.55-1.85 1.55 16.55 6.55-2.1-3.5 Coil -5.7-3.6 1.3-1.3-7.9-1 2.3
In the recent experiment the effects the environment has on a solar house were tested. The goal was to make a Hogan that would be heated by circulating heated water and antifreeze. The antifreeze was used inside the solar panel. The hope was that the heated antifreeze would self- circulate by thermal convection throughout the solar panel into the heat exchanger then into the Hogan. A fault occurred in the coiled set up because the poly tubing was laid out in coils rather than a wave design o Closely related temperatures o Antifreeze did not circulate Snaked design arrangement was successful in heating the Hogan. Data in second test supported hypothesis.
Influence future solar energy studies. Influence the application of solar energy on the Navajo Nation. Will reduced the use of non ecofriendly fuels. This concept can help reduce hard labor for Navajo elders that live independently. Make traditional housing more appealing to young Navajos. Increase endurance of Navajo tradition by modernizing and evolving.
Purpose : to build a solar Hogan and discover which section of the Hogan and which solar panel design would generate the greatest temperature inside the Hogan using water and antifreeze mediums. According to the results of the study the solar panel placed on section 2 with the snaked design was most effective in producing heat. The results support the hypothesis. Most significant findings : realization of how many concepts are already applied to current inventions. The evidence suggests that circulation is important when designing a solar system. This research will serve as a base for future studies and investigations of other options. This information can be used to develop targeted interventions aimed at solar home designs.
More work will need to be done to determine the effectiveness of the heat exchanger, solar panel, and Hogan insulation. When taking measurements it is suggested that temperatures be read carefully and Hogan roof is closed to prevent infiltration of outdoor temperature. A sufficient amount of time should be spent waiting for the thermometer to adjust in each environment. Many other changes can be made to find the most effective options. o The poly tubing inside the solar panel can be arranged in a wave like design rather than a coiled design.
Solar energy can easily be applied to homes Calculate accurate dimensions International and traditional connections Understanding various possible compromises Applying mathematics when constructing the Hogan Why this is important in my community o Tradition is being lost o Moves current technology found on the reservation forward Advantages of Radiant floor heating o Reduces allergies o Keeps all rooms warm o Energy efficient
I would like to thank our local Home Depot in Farmington, New Mexico for supporting me in my project by offering three twenty-five dollar vouchers for materials. We would also like to thank my parents for making helpful suggestions along the way. Big thanks to Amy and David Spencer for helping with the construction of the Hogan, research and picture taking. Ms. Flores, my Physics teacher was largely supportive through supplying instruments and information. Mr. Schramm, my art teacher was gracious enough to help with the construction of my solar panel so my thanks also goes to him. Lastly I would like to thank Ana Brown from Cal-Tech for help greatly with my understanding of solar energy.
Clark, J. (2002, October 13). The Effects of Surface Area on Rates of Reaction. Retrieved from Chemguide: http://www.chemguide.co.uk/physical/basicrates/surfacearea.html Clark, S. (1996). The Real Goods Independent Builder: Desigining and Building a House Your Own Way. White River Junction, VT: Chelsea Green Pub. Ewing, R. A. (2003). Power with Nature. Masonville, CO: PixyJack Press. Ewing, R. A., & Pratt, D. (2005). Got Sun? Go Solar: get free renewable energy to power your grid-tied home. Masonville, CO: PixyJack Press. Morris, C. (1992). Academic Press Dictionary of Science and Technology. San Diego: Academic Press. Nave, R. (n.d.). Heat Transfer. Retrieved February 08, 2014, from Hyper Physics: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heatra.html Scheffer, J. (2007). Solar Living Source Book. Hopland: Gaiam Americas. The Advantages of Radiant Floor Heating. (2014, March 11). Retrieved from Shamrock Plumbing: http://www.shamrockplumbing.net/radiant-floor-heating/ Thybony, S. (1999). The Hogan: The Traditional Navajo Home. Tucson, AZ: Southwest Parks and Monuments Association.