Space Zoo Patrol – Passive Solar Architecture
By Larry Hoffer, Executive Director, American Institute of Architecture Students
BACKGROUND
What is this technology called?
The name “passive solar” refers to the use of solar energy for heating and cooling. So, while it might sound like a technology, when we use passive solar design, we’re actually making use of a bunch of different technologies to make our buildings more comfortable to live in. The most important thing is that “passive solar” technologies don’t require any mechanical systems.
https://sustainablesources.com/energy/passive-solar-design/
How does it work?
There are 5 main elements for a passive solar design, and every building needs all of them to take full advantage. The aperture (a fancy name for windows) is where most of the sunlight enters the building and (if you live in the Northern Hemisphere) should always face South. The absorber is the place where all that sunlight hits the thermal mass. The thermal mass stores the heat sunlight produces, kind of like how the sidewalk heats up on a sunny day. The distribution is how that heat moves away from the thermal mass. A passive system will mostly let the heat rise through the house. Finally, the controller makes sure the windows don’t let in too much heat. Roof overhangs will shade windows in the summer, and most houses and apartments have blinds or curtains that do pretty much the same thing.
https://sustainability.williams.edu/green-building-basics/passive-solar-design/
Who invented it? And when and where?
Nobody is completely sure who first started using passive solar energy, because even the first buildings would pick up heat accidentally. We think the first people to create passive solar technologies were the Ancient Greeks in about 400 BCE. The Romans, however, were the first people to use windows made of glass to trap solar energy.
https://solar-energy.technology/what-is-solar-energy/history
ADVANTAGES
What are the environmental advantages?
Passive solar design and technology saves a lot of energy without a ton of material effort. Unlike adding solar panels or wind turbines to a house to lower its net energy consumption, passive solar designs use the same materials you would usually use to build a house, just in a unique way. This makes them REALLY efficient; there’s no sunk cost but just great benefits.
https://www.wbdg.org/resources/passive-solar-heating
What are the life cycle financial advantages?
Unlike most sustainable designs and technologies, passive solar technologies don’t have a high initial cost or a long-term payback period. A properly designed passive solar building won’t cost any more than a conventional one and will save a lot of money over time by lowering heating and cooling costs.
https://www.wbdg.org/resources/passive-solar-heating
What jobs are created? (design, manufacturing, installation)
Most jobs that work specifically with passive solar are design related. While lots of jobs are related to manufacturing concrete, bricks, stone, and windows, all of these materials are used whether the building is designed for passive solar or not. The most important people for a passive solar building are architects, who are trained in designing buildings to take full advantage of the technology. Other jobs created are engineering related: those people try to make more efficient materials (especially windows) to create more efficient houses.
ENERGY CONSERVATION
How efficient is this technology?
The efficiency of passive solar technology can vary based on a ton of things, from the latitude and orientation of the building to the surrounding climate, to surrounding buildings. In general, though, passive solar heating can reduce heating/cooling requirements from 5-25% without too much effort, and anywhere from 25-75% with more aggressive strategies.
https://www.wbdg.org/resources/passive-solar-heating
How many units are needed for 1 house, 1 school, 1 community?
Each house and building is unique, and the architect takes the design and location into account.
What percentage of the total population (US, world) uses this technology today?
Almost everybody uses some type of passive solar technology, especially in the United States. If you have windows in your house or apartment you can open, or blinds you can shut, that’s a piece of passive solar technology at work!
https://www.energy.gov/energysaver/passive-solar-home-design
What percentage of the total population (US, world) could use this technology?
At least in part due to the generality of passive solar (the sun is everywhere) absolutely everybody on earth can use passive solar technology! People in really hot places might need more shade and open windows, and people farther north will generally need more glass and mass to take up solar heat. Solar energy is something that everyone can use. The difference will usually be in how much you need. People in Canada will need more energy than in Mexico, for example.
https://www.treehugger.com/passive-solar-heating-5209238#toc-limitations-of-passive-solar-heating
What geographical areas can this be used in?
Pretty much anywhere on earth, except maybe deep in a cave, can use passive solar tech. What kind of passive solar tech is going to vary depending on where you are, but anyone can use it.
https://www.treehugger.com/passive-solar-heating-5209238#toc-limitations-of-passive-solar-heating
ENGINEERING / MECHANICAL
How is it manufactured?
This really depends on what kind of materials you’re using. Concrete is produced in a furnace, while bricks are shaped and fired. Windows are made from glass sheets that are then glazed and then assembled within a frame. For any of these materials, there are a lot of steps involved. https://www.northerncomfortwindows.com/blog/how-glass-windows-are-made
Where is it manufactured?
Some pieces of passive solar, like the thermal mass, are manufactured on the building site. Windows can be manufactured all over the world, but two of the biggest manufacturers in the US, Marvin Windows and Doors (No. 3), and Andersen Windows and Doors (No. 1), are based in Minnesota, and Jeld-Wen (No. 2), is based in North Carolina.
https://www.windowanddoor.com/article/top-100-manufacturers-2019-report
What maintenance is required?
Because they’re passive, these systems really don’t need very much maintenance. Unlike solar panels, which can break and will wear out over time, a building’s thermal mass is just as durable as the building is and can last for hundreds of years. Windows will need maintenance from time to time, just like any other window; but one of passive solar’s best selling points is its low-maintenance nature.
https://www.wbdg.org/resources/passive-solar-heating
EDUCATION
What classes should I take in school to work on this technology?
There are a bunch of sources for learning passive solar design. A lot of the classroom courses you’ll see are in college, like Environmental Technology or Sustainable Design. https://www.teachengineering.org/lessons/view/cub_housing_lesson05
PICTURES
