Passive Solar Home Designs

The solar home designs use natural sunlight to brighten up and warm the house. If the right panels are installed and operated, it can reduce the energy bills and achieve zero energy usage from the grids.

Designing and building a home is one of the huge and best investments you can make. We need to consider several aspects before constructing your house, and the most crucial factor to consider is the solar design.

The next millennium focuses on renewable energy resources as an alternative to fossil fuels. The reduction in the cost of solar panels is the primary reason for this drift. The design of your house contributes more to the cost and the amount of energy extracted from the solar panels.

In this article, let us discuss more solar home designs.

What are Solar Home Systems?

Solar Home systems are stand-alone PV (Photovoltaic) systems that provide power for lighting and appliances to houses not connected with power-grid in a cost-effective model. It can be used to meet the household energy needs in areas not connected to the grid.

They help in improving the standard of living of the people by,

  • Decreasing the air pollution
  • Improves health by replacing the kerosene lamps
  • Good lighting to work at night and
  • It gives access to people and information by establishing electricity connections for communication channels.
  • Avoids greenhouse gas

What are Passive Solar Home Designs?

The Passive solar home designs use the sun’s energy for heating and cooling the home space. When sunlight falls on the surface of the building, the building material can absorb, reflect, or transmit solar radiation.

The designed spaces can predict air movement caused by the heat produced by the sun. The reflection, absorption, and transmission of solar energy depend on the design, material choices, and location that influences the heating and cooling effects at home.

Passive solar energy does not include sophisticated tools or machineries like fans, pumps, or electrical controls to produce heat and electricity.

Passive Solar Designs

Passive solar designs comprise of five basic elements:

Aperture / Collector

The Aperture/collector is a large glass through which the sunlight hits the building. It should be 30 degrees south, and it should not be shaded by any tree or shadow of any other building from 9 AM to 3 PM during the summer.


It is a storage element that has a complex and darkened surface. The surface could be a masonry wall, floor, water container, or any hard surface placed in the path of the sunlight. It should be capable of absorbing the heat when the sunlight hits the surface.

Thermal Mass

Thermal mass is referred to those elements or materials that store the heat absorbed, and it is usually placed below the surface of the absorber.


Now that we have planned about collecting, absorbing, and storing the heat, we need to distribute the heat to various parts of the building to generate electricity and create a utility for the heat. Passive solar system uses three natural modes of transfer, including – Conduction. Convection and radiation.

In some instances, fans, ducts, and blowers may distribute the heat around the house.


During summer, there are high chances that the aperture gets overheated. To prevent overheating, you can choose roof overhangs. Other elements that can be used to control the overheating include electronic sensing devices such as a differential thermostat, which may indicate a signal to turn on; dampers that allow or restrict the flow of heat; operable vents, low-emissivity blinds, and awnings.

Passive Solar Heating

Passive solar heating is driven by the mechanism in which the sun`s heat is captured with the building using its elements. The heat is released throughout the building in the absence of the sun. The two main features required for passive solar heating are the south-facing glass and the thermal mass. However, there are different approaches for operating these elements, and it depends on the requirement of each building. There are two types of Passive solar heating designs, Direct and Indirect Gain.

Direct Gain

The Direct gain design uses the south-facing window to allow the sunlight to enter the house. The sunlight strikes the surface of the masonry floor/ wall, which absorbs and stores the heat. When the room temperature cools down during the night, the thermal mass helps release the heat into the room.

Some people use water-filled containers to absorb and store heat inside the home. Though it is believed that water can store twice as much heat stored in the masonry surface, the building must be carefully designed and structured to support thermal water storage.

Indirect Gain

A Trombe wall is the most common approach for indirect gain. In this design, the thermal storage lies between the south-facing wall and the living area.

The south side of the house is covered with an 8 to 16-inches masonry wall. The wall shall be dark in color so that when the single or double-layered glass is placed a few inches before the wall, the heat is absorbed and stored in the wall`s mass.

The heat flows through the wall and gets into the room. In the masonry wall, the heat can travel at an average rate of one inch per hour. The heat absorbed outside the wall will enter the house after 8 PM.

Passive Solar Cooling

The passive solar cooling systems work by reducing the excess or unwanted heat gained during the day by creating non-mechanical vents, making the warmer air cooler whenever possible, and storing the coolness of the night to replace the excess heat derived during the daytime.

In simple terms, they use the overhangs or shades towards the south-facing window, shade trees, thermal mass, and cross-ventilation.


If excess heat has been absorbed in the building, you can shade the south facing window, which helps reduce the heat falling on the surface of the glass. You can use overhangs or other devices like awnings, shutters, and trellises.

If cooling is a significant concern, try to minimize the east and west-facing windows.

Thermal Mass

Thermal mass is used to absorb the heat and adjust the internal temperature on hot days. During the night, it can cool down the temperature using ventilation, making it ready to absorb the heat the next day.

The same thermal mass can heat during the cold season and cool down during the hot season.


Natural ventilation helps maintain the inner temperature equal to the extreme temperature. But when to use them depends upon the climate outside and whether the internal temperature is similar to or greater than the temperature outside.