Geodesk - research, design, and manufacturing: March 2013

Geodesk is all about researching ideas and developing useful products just for the fun of it. The current to-do list is long, but a high priority item is designing a solar reflector with parabolic mirrors to focus infrared through ultraviolet light towards a collector; a hollow pipe filled with a circulating absorption media. The water should get hot enough to produce free hot water except for the cost of the materials needed to build the system. Water pumps and cooling fans may be necessary safety features if the system is not designed for dealing with steam.

In line with Geodesk's mantra, a collector design that uses little or no newly manufactured, toxic, or non-biodegradable materials will be made. The design will attempt to incorporate a solar-electric tracking system to operate as efficiently as possible for the season and time-of-day. A neat blog called George's workshop has an article about a pretty sophisticated sun-tracking solar reflector here that uses vacuum tubes as the collector to increase efficiency in cold weather.

Image obtained from George's Workshop blog

But what about hot water at night? Simple, cheap, and locally abundant materials with high heat capacities, like rock, sand, clay and water store a large amount of heat effectively. People have already figured this out. as you can see to the left is an attractive passive solar thermal mass called a water tube wall.

Passive Solar Water Tube Wall
Obtained from: https://www.thenaturalhome.com/img/waterTubeBlue2.jpg

Hydronics is the practice of using water for thermal energy storage and has been in use in radiant floor heating for people's homes for decades and possibly even centuries.

A radiant floor heating manifold with hot (inlet) and cold (outlet) sides, the tubing is called PEX (Cross-linked polyethylene)

Technically, a material with a high specific heat capacity (HC) will store a lot of heat given the opportunity, making a practical heat storage medium. Water's HC is 4.184 Joules per gram degree Kelvin, (it doesn't even need to be clean water), which is higher than most other materials.
Water can be pumped by a solar-electric-powered pump through a network of collectors and radiative tubing to heat floors, walls, air or water. Car or refrigerator radiators work well to radiate heat away from liquids and into the air. The car radiator works better with a fan so this could be setup to run from a low-powered solar-electric panel. The radiator can be contained in a ventiliation or circulation system in a wall, floor, or free standing to heat air.
Rock, tile, cement, and other insulators also make great thermal energy storage. Hot water can be pumped through tube networks in contact with the insulator to store heat. A trombe wall is an example of using passive solar directly without a hydronic network

A simple stone trombe wall. The downside to this design is the expense of the steel mesh.
Obtained from: http://media.treehugger.com/assets/images/2011/10/trombe-wall-bluff.jpg

Geodesk strives to design around basic principles: Materials we use and the waste we generate must be 100% recyclable and come from natural sources. By using natural materials, we are using sustainable nature-based design principles (also coined biomimicry or bionics). We are using up abundant and free resources and generating valuable products to benefit the environment and the community. For example, a large part of the Geohydrosolar system just mentioned could use materials already mined and mass produced for the automobile industries, destined for or already sitting in the junkyard i.e. mirrors, reinforced rubber hose (heater and radiator hoses), clamps, water pumps, heat exchangers (radiators and intercoolers), fans (both electric and pulley driven), and even gas tanks (mass storage). The geohydrosolar system could even be setup to purify water via distillation or run a steam turbine, all from using reclaimed materials and a lot of innovative design, research and rapid iterative improvements. Lastly, the geohydrosolar system can cool a hot house in a wet climate by using indirect evaporative cooling, this method requires putting a salt water solution under very high vacuum to make it boil at slightly below room temperature. Or, in dry climates, a hot house can be cooled using direct evaporative cooling, however this requires an abundant water source, which in dry locations can be scarce.

Enter the Namib desert beetle which can collect water on it's back in super dry climates, or maybe even Peruvian frog nets.

Obtained from Wikipedia

Another item on Geodesk's to-do list is designing a telescope for personal use. It could even be like the James Webb space telescope

James Webb Telescope Artist Impression
Obtained From: http://www.mnartists.org/uploads/users/user_6887/5363167d0bcd619b207654457ca3497e/5363167d0bcd619b207654457ca3497e.jpg

Misc. Solar Thermal Notes, Links and Videos

Biodegradable film

www.grafixplastics.com-downloads-Acetate_Stock_Sizes.pdf

PEX tubing manifold for radiant floor heating