More Information

Stop Our Deadly Addiction to Burning Oil

Emerald Eco-City TM Abundant Living In Harmony with Nature Self-Contained, Self-Sufficient, Sustainable Community Of A Million Productive Prosperous People Demonstrating State-Of-The-Art Practical Solutions

Introductory Passive Solar Energy Technology Overview Passive Solar Energy Heating Of Interior Air Passive Solar Energy Heating Of Water Passive Solar Energy Thermosiphon Passive Solar Energy Cooling

and DehumidificationIn A Hot Humid Climate

Earth Temperature Cool Tubes Solar Energy Primer Slides US Solar Energy Potential US Solar Photovoltaic Capacity Example Photovoltaic System Payback Period Purchase $25 ZED CD-ROM

"Three Decades of Lessons Learned"850-page eBook PDF + 3,000+ DOE slides

Please browse our Friends Sites ZeroEnergyDesign.com Passive Solar Energy Technology Website

Enterprise System Integration.com Cost-Effective, State-Of-The-Art, Enterprise Architecture - Rapid Implementation

Methodology

Corrupt Energy Politics Arguably The Most Myopic Issue in AmericaZED.org

Joyful Aging.com, Information for Healthy Lifestyle Choices

Passive Solar Energy Heating For Cold Climates, andPassive Solar COOLING For Hot Humid Climates

The term “Passive Solar Energy” means that basic physical concepts (such as sunshine, warm air rising, and cool air falling) are used to HEAT and COOL a building, WITHOUT the need for fans, water pumps, or other “active” mechanical equipment. Using solar radiation to Passively Heat Air and Water is VERY EASY AND INEXPENSIVE TO DO.

Using the sun's solar energy for Cooling and Dehumidification in a hot humid climate, (where the nighttime air is too warm and contains too much water vapor to use for direct ventilation), is a challenging engineering problem that Zero Energy DesignTM, Inc. solved cost effectively in 1979, without the use of expensive conventional compressor-based air conditioning equipment.

When nighttime air is TOO WARM (above 80 degrees F) and it contains TOO MUCH WATER VAPOR (above 50% Relative Humidity) then it should NOT be used for direct building ventilation. We must have some method of cooling the air and removing water vapor from it. Our achievable, proven Zero Energy Design goal is to eliminate net energy bills by doing precisely that. VERY FEW people (other than those trained by Zero Energy DesignTM) understand the practical state-of-the-art design-and-implementation issues of Passive Solar Energy Cooling in a Hot, Humid Climate.

The U.S. Department Of Energy and Oakridge National Laboratories selected us to present a full-day workshop on “Three Decades Of Passive Solar Energy Heating and COOLING” at their prestigious International Buildings Conference. (www.ZeroEnergyDesign.com/doe.html) (www.ornl.gov/sci/buildings/Workshops_07.html#14)

We now offer our 850-page ZED eBook PDF, our 3,000+ DOE Passive Solar Energy Workshop and Future Energy slides, and thousands of pages of other bonus materials on our CD-ROM for only $25. Zero Energy DesignTM ebook

We are committed Passive Solar Energy Research Scientists with a long track record of consistent success. We provide three decades of experience, extensive comprehensive solution specifics, and many details that are simply NOT available for any other source. Our materials are internationally copyrighted, but we have chosen to NOT patten our proven designs, for the betterment of humanity.

Some Passive Solar Energy techniques were understood by ancient Greeks 2500 years ago, like orienting entire communities with tens of thousands of buildings so that every one takes advantage of winter sunshine, while blocking the hot summer sun (when it is 47 degrees higher than the low winter sun). Some modern Passive Solar Energy techniques are very-new “state of the art” that do not yet appear in any other text book. For 30 years (since Jimmy Carter’s 1978 Solar Energy Tax Credits) Natural Energy Applied Research, and Zero Energy Design, inc., have been demonstrating state-of-the-art Passive Solar Energy technology that can eliminate conventional heating and cooling bills. Our ZED book has been growing, and iteratively refined for nearly THREE DECADES. Our ZED CD-ROM is the most comprehensive and complete information resource on Passive Solar Energy Heating and especially Passive Solar Energy Cooling that we have ever heard of anywhere. We hold nothing back - It answers most of the questions we have been asked over three decades.

Today, we design Zero Energy Buildings that can have NO ENERGY BILLS. They do not even have to be connected to any energy company. After construction, they produce NO GREENHOUSE GASES, and do NOT contribute to man-made climate change Global Warming, or pollution of our delicate environment. Our buildings can help eliminate the need to ever build any more fossil fuel or nuclear power plants.

Your Passive Solar Energy information source is our comprehensive 850+ page Zero Energy DesignTM ebook pdf on CD-ROM with hundreds of full color illustrations, photos, and diagrams.

6-minute "Abundant Energy Brilliant Future"Narrated Introductory ZED Video

If this video stops or plays slowly on your computer, click on the lower left Pause button (||).Wait a minute or two for the download to catch up, and then click on Play (>).

Introductory Passive Solar Energy Technology Overview

Passive Solar Energy Concepts can be added to any existing building (obviously for additional cost). BUT, Passive Solar Energy Technology is the LEAST EXPENSIVE (and the most effective) when it is holistically integrated into the exterior envelope of a NEW building. Passive Solar Energy new construction can actually COST LESS per square foot than traditional construction, since Passive Solar Energy Design, plus Holistic Systems Engineering, can REDUCE (or eliminate) the need for expensive-to-install-and-operate conventional heating and cooling systems.

Return to Top

Seasonal and Hourly Sun Path

If we are going to use the clean, FREE, renewable energy from the sun, we must know where it is going to be.

Earth's rotation tilts about 23.5 degrees on its pole-to-pole axis, relative to the plane of Earth's solar system orbit around our sun. As the Earth orbits the sun, this creates the 47-degree peak solar altitude angle difference, and the hemisphere-specific difference between summer and winter.

In the Northern hemisphere, the winter sun rises in the southeast, peaks out at a low angle above the southern horizon, and then sets in the southwest. It is on the south (equator) side of the house all day long. Vertical south-facing (equator side) glass is excellent for capturing solar thermal energy.

This is not true in the summer, when in the northern hemisphere, the sun rises in the northeast, peaks out nearly straight overhead (depending on latitude), and then sets in the northwest. A simple latitude-dependant equator-side overhang can easily be designed to block 100% of the direct solar gain from entering vertical south-facing windows on the hottest days of the year. Roll-down exterior shade screens, interior translucent-or-opaque window quilts, drapes, shutters, movable trellises, etc. can be used for hourly, daily or seasonal sun and heat transfer control (without any active electrical air conditioning).

The latitude (and hemisphere)-specific solar path differences are critical to effective passive solar building design. They are essential data for optimal window and overhang seasonal design. Solar designers must know the precise solar path angles for each location they design for, and how they compare to place-based seasonal heating and cooling requirements.

In the U.S., the precise location-specific altitude-and-azimuth seasonal solar path numbers are available from NOAA - The "equator side" of a building is south in the Northern hemisphere, and north in the Southern hemisphere, where the peak summer solstice solar altitude occurs on december 21st. The sun rises in the east and sets in the west everywhere on Earth.

On the Equator, the sun will be straight overhead and a vertical stick will cast no shadow at noon (solar time) on March 21 and September 21, the equinox. 23.5 degrees north of the equator on the Tropic of Cancer, a vertical stick will cast no shadow on June 21, the summer solstice. The rest of the year, the noon shadow will point to the North pole. 23.5 degrees south of the equator on the Tropic of Capricorn, a vertical stick will cast no shadow on December 21, the summer solstice, and the rest of the year its noon shadow will point to the South pole. North of the Tropic of Cancer, the noon shadow will always point north, and conversely, south of the Tropic of Capricorn, the noon shadow will always point south. North of the Arctic circle, and south of the Antarctic circle there will be at least one day a year when the sun is not above the horizon for 24 hours, and at least one day (six months later) when the sun is above the horizon for 24-hours.

In the moderate latitudes (between the circles and tropics, where most humans live), the length of the day, solar altitude and azimuth vary from one day to the next, and from season to season. The difference between the length of a long summer day, versus a short winter day increases as you move farther away from the equator.

All passive solar building designers must know this absolutely-critical environmental information precisely for their specific location. It has to be included in 3D seasonal solar-design mathematical computer simulation models, used by modern passive solar building designers.

When designing active solar panels, it is also important to be familiar with the latitude-specific seasonal hourly path of the sun.

 

 

 

 

 

 

Passive Solar Energy Heating Of Interior Air in a cold climate (with typical U.S. levels of sunshine) is extremely EASY and inexpensive to implement. Passive Solar Energy Heating begins with VERTICAL EQUATOR-SIDE (SOUTH-FACING) GLASS (or north-facing glass in the southern hemisphere). The winter sun is quite low (often less than 30 degrees above the horizon) in the winter. Direct sunlight easily penetrates vertical glass and can heat a room well

above 80 degrees F, when it is below freezing outside.

When there is snow on the ground, the reflection of the low winter sun off of the snow significantly increases the Passive Solar Energy Heating effect, with reflected sunlight on your interior ceiling.

In the summer, the noonday sun is 47 degrees higher than in the winter. Place-based, location-specific overhangs are designed above the equator-side windows, so that NO DIRECT SUNLIGHT CAN ENTER THE GLASS IN THE SUMMER, when the sun rises in the northeast, is nearly straight overhead at noon, and then sets in the northwest. Understanding the PRECISE seasonal path of the sun in your location is critical to effective PASSIVE SOLAR ENERGY HEATING, and PASSIVE SOLAR ENERGY COOLING, especially in hot humid climates.

Roof-angled glass should ALWAYS BE AVOIDED IN ALL LOCATIONS. Roof-angled glass (and most skylights) are a SOLAR FURNACE when the summer sun is nearly straight over head. Most of low winter sunlight reflects off of roof angled glass (due to the nearly-parallel “angle of incidence”).

In the winter, warm air rises and the hottest air in the room touches your ceiling glass. This creates high heat transfer (large energy bills), due to the large temperature differential across the ceiling glass, which has low resistance to heat flow. Roof-angled glass is like a THERMAL HOLE in your ceiling / roof.

If you ever see any building with roof-angled glass, or skylights, then you can be certain that its designer did NOT have the first clue about the ancient engineering principles of Passive Solar Energy Design. The Romans who invented glass over two thousand years ago quickly discovered that roof-angled was very bad thermally: summer AND winter. Roof glass also often leaks water, and can break in a hail-or-wind storm. If you currently have roof-angled glass in your home, it should be removed and the hole weather sealed and well insulated.

Thermal Buffer Zone"

THERMAL BUFFER ZONE

– at moderate temperatures that are typically between interior and exterior temperature extremes. There is then a lot of INTERIOR glass that divides the Solarium / Greenhouse space from the interior of your home. Instead of having only one wall between your interior and outside temperature extremes, you have TWO layers of glass. The engineering principle is that TWO SMALL TEMPERATURE DIFFERENTIALS PRODUCE MUCH LOWER HEAT TRANSFER THAN ONE LARGE TEMPERATURE DIFFERENTIAL

The amount of south-facing solar heating glass is determined by the local solar gain potential, and the degree-day heating requirement in the winter. It is even needed in the northern half of tropical Florida, where the winter temperature sometimes drops below freezing when the frigid Canadian jet stream swings south.

In the past, passive solar designers have often used too much glass and been surprised at the need to exhaust excess heat on very cold clear winter days. We have also observed that winter solar gain increases due to reflection from the low angle of the sun through vertical south-facing glass, when snow is on the ground. This is a desirable winter heating characteristic of passive solar design that architects need to understand when sizing solar glass in snowy climates.

During winter days, the Solarium is heated nicely from CLEAN, FREE, Abundantly-Available, Passive Solar Radiation. We design in Natural Convection Air Flow Paths so that south-side solar gain is transferred to the colder rooms on the north side of your house, without the need for fans, thermostats, or electricity.

The amount of south-facing solar heating glass is determined by the local solar gain potential, and the degree-day heating requirement in the winter. It is even needed in the northern half of tropical Florida, where the winter temperature sometimes drops below freezing when the frigid Canadian jet stream swings south.

In the past, passive solar designers have often used too much glass and been surprised at the need to exhaust excess heat on very cold clear winter days. We have also observed that winter solar gain increases due to reflection from the low angle of the sun through vertical south-facing glass, when snow is on the ground. This is a desirable winter heating characteristic of passive solar design that architects need to understand when sizing solar glass in snowy climates.

Excess daytime solar heat is stored in THERMAL MASS that is engineered into your Passive Solar Home. It prevents your home from getting too warm on sunny winter days, and it heats your entire home on cold winter nights. When the air outside gets extremely cold in the winter, the moisture precipitates out (as snow, etc.). This leaves clear skies, excellent solar gain, which is enhanced by reflection off of the snow that lights up the CEILING of your Solarium. How wonderful!

The Zero Energy DesignTM Thermal Buffer Zone experiences small temperature swings that are much less than the outside temperature, and the interior of your home remains a fairly stable temperature and humidity, without the harsh drying effect of a conventional expensive heating system. The interior of your home “thinks” it was built in a tropical environment where it can get 88 degrees F (with snow on the ground on sunny days) and only the low 60’s at night (in most U.S. locations). Sunbathing in the warmth of the Solarium on a cold winter day is exhilarating. Your skin gets nice and warm, but you cannot get a sunburn through the south-facing glass, which blocks most harmful ultraviolet rays.

The Sunroom / Solarium / Greenhouse is a great place for a year-round solar-heated swimming pool, swim spa, or hot tub. Our first Zero Energy DesignTM Passive Solar Home in 1979 had a 38-foot indoor swimming pool. We swam in 90 degree F solar heated water, with 10 degree snow outside. Almost everyone who toured our innovative 1979 home were more impressed with its unique beauty, than with the fact that we did it with no heating or cooling bills. We have learned much more since then.

In moderately cold U.S. climates, we often use a lot of south-facing glass (up to ceiling-to-floor, wall-to-wall in some locations). There is then sweeping INTERIOR glass that divides the Solarium / Greenhouse space from the interior of your home, and creates panoramic southern views in most room of the house. Our house plans are NOT conventional with indiscriminate use of glass on all sides of the envelope.

Instead of having only one wall between your interior and the summer / winter outside temperature extremes, our Passive Solar Energy Homes have TWO layers of glass. The engineering principle is that TWO SMALL TEMPERATURE DIFFERENTIALS PRODUCE MUCH LOWER HEAT TRANSFER THAN ONE LARGE TEMPERATURE DIFFERENTIAL as in the case of a traditional building with no Thermal Buffer Zone on any side.

During winter days, our equator-side sunrooms are heated nicely from CLEAN, FREE, Abundantly-Available, Passive Solar Energy Radiation. We design in “Natural Convection Air Flow Paths” so the south-side warm air is transferred to the colder rooms on the north side of your house, WITHOUT the need for fans, thermostats, or electricity. The sunnier that it is outside, and the colder the north side, the higher the north-to-south pressure differential will be, and the faster our self-regulating convection air flow becomes.

Excess daytime Passive Solar Energy is stored in THERMAL MASS that is engineered into your Passive Solar Energy Home. The Thermal Mass prevents your home from getting too warm on sunny winter days, and it heats your entire home on cold winter nights – allowing only very gradual temperature changes from day to night, and from one season to the next.

When the air outside gets extremely cold in the winter, the water vapor in it precipitates out (as snow, etc.). This leaves clear skies and excellent solar gain, which can be greatly enhanced by reflection off of the snow - Which lights up the CEILING of your Solarium. How wonderful! Extreme cold, implies high Passive Solar Energy Heating potential, in most locations with north and south latitudes that are similar to those of the continental United States.

Our Zero Energy DesignTM Thermal Buffer Zone experiences small temperature swings that are much less than the outside temperature, and the interior of your home remains a fairly stable temperature and humidity, without the harsh drying effect of a conventional expensive heating system. The interior of your Passive Solar Energy home “thinks” it was built in a tropical environment, where the solarium can get 88 degrees F (with snow on the ground on sunny days) and only the low 60’s at night (in most U.S. locations). Sunbathing in the warmth of the equator-side Solarium on a cold winter day is exhilarating. Your skin gets nice and warm, but you can NOT get a sunburn through the south-facing glass, which blocks most of the sun’s harmful ultraviolet rays.