09/02/2021 | Press release | Archived content
What Is Passive Solar Energy?
What is the difference between active and passive solar energy? Most people associate solar energy with photovoltaic panels and electricity.
How Is Passive Solar Design Achieved?
Homes can benefit from passive solar energy with a few design basics. There are five of these in total, which can provide highly efficient heating and cooling.
How Does Passive Solar Energy and Work with HVAC?
Passive solar heating systems capture heat from the sun within the building. That heat is released when sunlight isn't available. A direct gain design allows sunlight in through south-facing windows while floors and walls absorb and store heat. The thermal mass releases heat into the home during the night with 60% to 70% of the sun's energy used. Water-filled containers may be installed within the living space, if the structure can support them (per cubic foot, water stores 2x as much heat as masonry).
Indirect gain works by placing the thermal mass between the sun and living space; sunlight is then transferred via conduction. Using 30% to 45% of the sun's energy that strikes the glass, indirect gain can be achieved with a Trombe wall. A dark-colored masonry wall placed 1 inch or less behind south facing glass absorbs solar heat, which then radiates into the interior. By late afternoon or early evening, solar heat has migrated to the interior surface of the wall. Heat starts radiating into the room when the indoor temperature falls and reaches a lower level than that of the surface.
Passive solar cooling systems use non-mechanical ventilation to reduce unwanted heat gain. It is accomplished through shading by overhangs, awnings, or trees. Ventilation can help cool the thermal mass at night so it can absorb heat once again the next day. Natural ventilation such as an open window is a great source of passive cooling; with wing walls, you can draw in air through windows situated perpendicular to the breeze.
Both active and passive solar energy can help make your home more energy efficient. If you're thinking of investing in a solar system for your home, Sunworks can manage your entire solar project, from permitting and design to construction and operation. Call 866-600-6800 to learn more and discuss the details of your project.