In places of hot climate it is advised that the outer walls of houses be painted white. Explain.

Painting the outer walls of houses white in hot climates serves several beneficial purposes:

1. Reflectivity: White surfaces reflect sunlight and a significant portion of solar radiation, including heat. Rather than absorbing heat, the white paint reflects sunlight, helping to keep both the surface and the interior of the house cooler.

2. Heat Reduction: Lighter colors like white absorb less heat compared to darker shades. This means that white-painted surfaces absorb less heat from the sun, preventing excessive heating of the building materials.

3. Energy Efficiency: By minimizing heat absorption, white-painted buildings require less energy for cooling. Consequently, internal cooling systems, such as air conditioning, work more efficiently, reducing energy consumption and associated costs.

4. Improved Indoor Comfort: With cooler exterior walls, there’s reduced heat transfer into the interior spaces. This helps maintain more comfortable temperatures indoors, diminishing the need for constant cooling and fostering a more pleasant living environment.

5. Preservation of Building Materials: Excessive heat can degrade building materials over time. White-painted surfaces, by reflecting sunlight and minimizing heat absorption, can potentially prolong the lifespan of building materials by reducing heat-related damage.

In essence, painting house exteriors white in hot climates minimizes heat absorption, curtails indoor temperatures, lowers energy consumption, and may extend the durability of building materials, making it a prudent strategy for hot climate regions.