Cooling from the Ground

• M. Rothkranz

  Author

Earth to air heat exchangers, often called earth tubes, move outdoor or return air through buried ducts so that heat flows between the air and the surrounding soil. The concept can reduce cooling and heating energy because a fan requires far less power than a vapor compression system. What this project calls for is a forty foot, eight inch tube buried four feet deep, with a screened intake, an inline fan, a condensate slope, and a material cost below 300 United States dollars as of 2026 in Las Vegas, Nevada. What I am proposing is an appealing idea, but it cannot be applied universally, because soil at four feet is not always 55°F, the seasonal phase delay at that depth is not six months, fan electricity is not zero, drainage does not guarantee permanent freedom from mold, permits may be required, and a single short tube cannot be presumed to meet a whole house cooling load. This paper converts the useful core idea into a technically bounded, open source design. The proposed architecture uses site-measured ground temperature, one or more smooth and sealed parallel tubes, positive pressure operation, accessible condensate collection, filtration, a weather and smoke bypass, differential temperature control, radon testing, and documented commissioning. A first order effectiveness model is presented alongside a Las Vegas example. Using an illustrative overall heat transfer coefficient of 10 W per square meter kelvin, 105°F inlet air, and 77°F ground, one forty foot, eight inch tube is predicted to deliver approximately 2,208 to 3,298 Btu per hour across 100 to 300 cubic feet per minute, with outlet air from about 84°F to 94°F. Three parallel one hundred foot tubes at 100 cubic feet per minute each are predicted to approach 8,472 Btu per hour under the same ground condition. These values are design estimates, not measured prototype results. The proposed system is therefore best described as a low power air temperer, ventilation preconditioner, or hybrid cooling stage. Whole house standalone cooling is possible only when measured capacity equals the building load under site specific conditions. A complete installation, instrumentation, commissioning, maintenance, risk, and publication protocol is provided so that future claims can rest on reproducible evidence rather than slogans.

1. M. Rothkranz
   About the Author: Markus Rothkranz

   Markus Rothkranz is an inventor, designer, filmmaker, visual-effects artist, author, entrepreneur, and advocate of practical energy independence whose career has crossed an unusually broad range of creative and technical disciplines. From advanced electronics and theoretical-physics studies in his youth to Hollywood visual effects, patented mechanical inventions, independent filmmaking, solar-powered living, and sustainable residential design, Rothkranz has spent much of his life exploring how artistic imagination, mechanical ingenuity, and practical experimentation can be brought together to solve real-world problems.

   Rothkranz demonstrated an interest in engineering concepts, model construction, electronics, and visual design from an early age. As a teenager in Ontario, Canada, he undertook advanced electronics studies and developed a strong personal interest in theoretical physics. Contemporary biographical accounts describe this period as formative in developing the technical curiosity that would characterize much of his later work. He simultaneously pursued art, mechanical construction, and large-scale modeling. While attending Huron Heights Secondary School, Rothkranz constructed an elaborate working miniature representation of Walt Disney World. A surviving Toronto Star photograph from 1978 documents the teenage Rothkranz with the approximately nine-by-ten-foot project, which incorporated mechanically operating elements rather than functioning merely as a static model.

   After secondary school, Rothkranz moved to Florida and attended the Ringling School of Art and Design, now known as Ringling College of Art and Design. His education and independent experimentation increasingly combined visual art with architecture, mechanical construction, electronics, miniature building, and photographic realism. Rather than remaining within a single discipline, he developed the multidisciplinary approach that would later characterize both his film work and his inventions.

   Rothkranz eventually entered the motion-picture industry, working professionally in design, scenic construction, miniature effects, matte painting, and visual effects. His professional history includes work associated with major Hollywood productions, including Total Recall, as well as commercial and entertainment design projects. His own career accounts describe participation in hundreds of television commercials, music videos, miniature constructions, visual-effects sequences, and related productions. His strength was particularly suited to the era before modern computer-generated imagery, when convincing imaginary environments often had to be physically built, painted, photographed, illuminated, and integrated into live-action footage.

   That combination of engineering-minded problem solving and visual design later carried Rothkranz into the gaming industry. He became involved in the artwork and design of commercially successful pinball machines associated with major entertainment properties, including Star Wars, Jurassic Park, Lethal Weapon 3, Guns N’ Roses, Baywatch, Tales from the Crypt, Last Action Hero, and The Who’s Tommy Pinball Wizard. More importantly from an engineering standpoint, Rothkranz progressed from designing the appearance of gaming equipment to inventing mechanical systems used within gaming devices.

   United States and international patent records identify Rothkranz as an inventor or co-inventor on numerous gaming-machine technologies. Among them is U.S. Patent 7,153,209, describing independently linearly movable mechanical symbol indicators, as well as patented systems involving rotating and pivoting symbol mechanisms, multiple-image display panels, and moving indicators. These records provide a tangible technical legacy demonstrating that his design work extended beyond aesthetics into functional mechanical invention and commercial product development.

   One of Rothkranz's most ambitious creative undertakings was the feature-length fantasy film To the Ends of Time. Rothkranz conceived, wrote, and directed the production, which starred Joss Ackland, Christine Taylor, Sarah Douglas, and Tom Schultz. The American Film Institute records Rothkranz as the film's director. Produced during an era in which large-scale digital visual effects were not yet readily available to independent filmmakers, the film relied heavily on practical effects, miniature construction, matte work, elaborate sets, costumes, pyrotechnics, location photography, and orchestral scoring. Rothkranz has described personally constructing hundreds of miniature elements and participating directly in numerous aspects of the production. AFI characterized the film as an ambitious fantasy adventure built around imaginative technology and manipulation of time.

   In subsequent years, Rothkranz increasingly directed his attention toward self-reliance, efficient residential systems, renewable energy, and sustainable living. Rather than treating sustainability merely as an abstract environmental philosophy, he incorporated many of these ideas into his own residence. Public biographies have described his Las Vegas home as solar powered, and Rothkranz produced the instructional film Solar Power 4 Me to demonstrate residential solar generation, battery-based off-grid systems, grid-interactive systems, insulation, thermal mass, efficient water heating, and strategies for lowering household energy demand. The program emphasized a principle that would recur throughout his later work: reducing energy consumption can be as important as generating additional energy.

   This practical approach to sustainability provides the background for Rothkranz's continuing interest in unconventional but physically testable methods of residential heating and cooling. His approach is characteristically hands-on: construct the system, measure its performance, identify its limitations, improve the design, and make the underlying concept accessible to others.

   Cooling from the Ground continues that tradition. The project examines how the comparatively stable temperature of the subsurface environment can be used as a low-power thermal resource for residential cooling through an earth-to-air heat-exchange system. Consistent with Rothkranz's broader philosophy of practical independence, the design emphasizes straightforward construction, low electrical demand, safety controls, condensate management, measurable performance, and open dissemination rather than proprietary restriction.

   Across more than four decades of creative and technical work, Markus Rothkranz has moved between art, filmmaking, mechanical invention, energy systems, construction, education, and sustainable living. The common thread is a belief that complicated problems become approachable when imagination is combined with experimentation and practical construction. His career reflects the perspective of a lifelong designer and inventor: if a better way of doing something can be imagined, it should be built, tested, measured, refined, and shared.

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