Old Solar: 1881

Edward Sylvester Morse patented his air heater in 1881. It is still a great design with a versatile vent system.

A simple glazed box on the south wall with a dark absorber, an air space, and two sets of vents at top and bottom, to the outside air and the inside of the house, this is a basic air heater that can be modified for wall or window.

Edward Sylvester Morse built at least three of these. One was at the Peabody Museum in Salem, MA and used an iron absorber panel. The second had a slate absorber and was on his own home, also in Salem. The last was at the Boston Athenaeum. He also lectured on the topic at MIT and published a pamphlet on his solar air heater findings.

ES Morse was a remarkable gentleman. Not only did he teach at the Essex Institute in Salem, MA but he lived and taught in Japan and traveled to China. His book, _Japanese Homes and Their Surroundings_, is still in print and a great primer on traditional Japanese culture. He was a president of the American Association for the Advancement of Science and wrote wonderful reports on topics as diverse as noise pollution, archaeology, and natural science. I especially enjoyed "Fireflies Flashing in Unison."

SolarWall is a modern adaptation of Morse's idea. It is an unglazed perforated absorber. A fan draws outside air through the absorber and into the heated space. It gets up to 75% thermal efficiency they say.

Solarwall uses the air flow pattern shown in the leftmost illustration of Morse's patent. The TAP (Thermosiphon Air Panel) is an example of the middle illustration, cycling room air past the absorber in a closed loop, full heating mode. The third illustration shows an air chimney from the floor of the room to the top of the absorber, a cooling technique.

I'd like to see a Morse collector with modern materials, PV fan assist, and controls that monitor and maximize the vent system. Could be interesting.

Old Solar: Eames Solar Do-Nothing Machine

Old Solar: 1980 Barnraised Solar AIr Heater

Old Solar: Keck and Keck Twentieth Century Modern Old Solar: Venetian Vernacular
More on simple solar devices:
A South-Facing Window Is Already a Solar Collector

Simple Solar - Parts 1, 2, and 3

I presented a workshop on Simple Solar at the Boston Skill Share on a windy Sunday, April 19, outside the Stata Center at MIT. Werner and Julie of Videosphere recorded me and I finally got around to doing a rough edit of the first part, the simplest solar devices that anyone can make to disinfect and heat water and cook food.

It's six and a half minutes long, I have the sniffles and say "All right?" a lot but the rest of the information is good. After all, solar heating is remarkably simple:
dark heats up
light reflects
clear keeps out the wind



Boiling water and cooking with the Simple Solar principles and using the basic geometry of the parabolic curve to focus light in a line and a circle with a parabolic trough and parabolic dish.



The late Tim Harkness made the parabolic dish used in the video on that windy April day. There is a Tim Harkness Fund for Invention at Hampshire College which awards grants for innovative work in applied design and invention, especially in areas of sustainability and renewable energy. Students and alumni from the Five Colleges are eligible.

How to Draw a Parabola

Draw a Parabola with pencil and string



Simple solar windowbox air heater for supplemental heating of a single room. This device uses a solar electric fan assist and can be built full scale (2 feet x 4 feet) for about $100 worth of materials.

More on the Windowbox Solar Air Heater

More on simple solar devices:
A South-Facing Window Is Already a Solar Collector
Your Southernmost Window
Solar IS Civil Defense
Solar IS Civil Defense, Illustrated

Earlier Diaries:
Old Solar: 1980 Barnraised Solar Air Heater
Old Solar: Keck and Keck Twentieth Century Modern
Old Solar: Venetian Vernacular
Old Solar: 1881

Windowbox Solar Air Heater

This is a demonstration model of a solar windowbox air heater.

You can build it from a sheet of insulation board, some clear glass or plastic, and a furnace air filter painted black.

When the sun shines, the black absorber inside the insulated windowbox gets hot, heating air which rises into the room behind the window, and drawing cooler air from inside that room past the absorber in a thermal loop that lasts until the sun goes down.

At night, the cold air sinks to the bottom of the windowbox and closes off this thermal loop so there is no additional night time heat loss.

Increase the efficiency of the windowbox solar air heater with a solar electric, photovoltaic, PV fan.

This demonstration model uses a repurposed solar car window ventilator. Only when the sun hits the PV panel does the fan move air, an automatic solar circuit thermostatic control.

The windowbox solar air heater is a supplemental heater for one room with a south-facing window and can be modified to provide increased ventilation and cooling in the summer as Edward Sylvester Morse's 1881 solar air heater design did.



Cost for a 2 foot by 3 foot insulation board solar windowbox air heater is around $100. PV fan car vents are available for as little as $5. One recently built windowbox has heated air by at least 20º Fahrenheit, from 65 to 85º, and will do so all winter.