How a SunCatcher Works

When you think about how to do year round gardening or growing in colder climates, we know you have the same concerns that we do:

  • Is the solution sustainable and eco-friendly?
  • Is this going to take more of my time and energy to manage than a conventional garden?
  • How much is this going to cost?

SunCatchers are uniquely designed with these concerns in mind – a true passive solar greenhouse, with the sun as the only source of light and heat, year round (as opposed to an “active” greenhouse which requires heating in winter, venting on sunny days, and generally more management). We use the sun, laws of nature and natural elements to provide an increase in available natural sunlight for plant growth, heat at night and on cold overcast days, and a CO2 rich environment for enhanced year-round plant growth in most any climate.

By optimizing the power of the sun, we provide you with a growing environment that is:

  • Eco-friendly – fossil fueled heating and grid power not necessary
  • Easier to manage – you don’t have to worry about heaters, fans, high humidity, regular maintenance, or other issues of a conventional greenhouse.
  • Sustainable – SunCatchers are engineered to last for generations without need for major materials replacement/new inputs
  • Cheaper – there is a higher up-front cost (partially offset by green building tax credits) but these should be fully offset by savings in heating and cooling, materials replacement, etc versus a typical greenhouse within 8-10 years of construction.

How do we do it?

The design of a SunCatcher takes advantage of the changing angles of the sun throughout the seasons to maximize solar input during the coldest months (winter) that results in increased heating and photosynthesis. Then during the hottest months (summer) solar input is minimized to reduce heating and to allow diffuse light for photosynthesis. The design acts like a natural thermostat, producing extra heat in the winter during clear days when plants are undergoing maximum photosynthesis so that fresh air can be introduced while excess moisture and CO2 depleted air are vented. As the seasonal temperatures warm, the structure reduces the solar heating input.

In the northern hemisphere, the winter sun travels in the southern portion of the sky, rising in the east and setting in the west. Therefore, it is important to face your SunCatcher’s glazed surface as close to south as possible.

The path of the winter sun will always be lower in the sky with a shorter path than the summer sun.

Because the sun is lower in the sky in the winter months, the site must be clear of obstacles to the south that may cast long shadows on the site during the winter. For best performance, the site must receive all-day sunlight during the winter months.

The 5 Elements of the SunCatcher PSG: SunCatchers have the ability to directly harness the sun’s light energy and make it available for heating the SunCatcher at night and on overcast winter days. Collecting, converting, and storing the low-angle winter sun’s energy for heating the structure 24 hours a day is accomplished through the use of:

  1. Orientation
  2. Glazing
  3. Thermal mass
  4. Insulation
  5. Ventilation

So, is it difficult to operate a SunCatcher? Absolutely Not. Read More…

Your location’s heating needs: A SunCatcher is designed to capture and store solar heat so that conventional heating equipment is not needed and has been proven at zone 6B of the USDA’s Plant Hardiness Zone Map.

The temperatures maintained in a SunCatcher are determined by the amount of south-facing glazing (which provides energy into the structure) and how well insulated the structure is (which reduces heat loss).

Colder locations (zones 6A to 4A) will want to consider the nighttime shade to prevent heat loss through the glazing during the night. Extremely cold climates (zone 3B and colder) will require some supplemental heat. The amount of sunlight during the winter also plays a critical factor in determining your location’s needs. You can refer to the National Renewable Energy Lab’s PV Solar Radiation Static Maps to see your location’s solar availability each month and click on the map below to find your location’s hardiness zone. These can help determine heating and lighting needs for the winter.

Click on map to go to an interactive version of the map to find your location.

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