In areas with cold climates, we bundle up to stay warm. In essence, what we’re doing is insulating our bodies against the cold. In much the same way, insulation is what helps keep buildings – your home included – nice and cool inside even when it’s sweltering out. You may ask: How does insulation help my home in a tropical climate?
Well, one thing about heat is that it isn’t static. It moves, and it can easily enter your home, making it hotter than you want it to be. Let’s try to understand how heat moves inside your home in the first place, where it stays, and where it escapes to, exactly.
Heat moves and flows in and out of your home – traveling through conduction, convection, and radiation.
The ground on which your house stands is soil or rock that absorbs the heat that flows down directly from the sun to the Earth. This heat moves through your walls, floors and your roof. Now, what happens to that heat? One of three things:
• The heat that is conducted through the metal, brick, and other materials of your home’s structure heats up the air both inside and outside the home. It enters your home through metal door frames and window frames, or is absorbed by concrete floors.
• In the same way that you feel the heat radiating from something hot – such as a campfire or fireplace – the heat in your home is constantly radiated from the sun and back into the atmosphere. This explains why heat from the sun can be felt directly, even when you’re in a cold room. Radiation is also how infrared photos capture heat movement inside your home.
• As air gets warmer, it rises. Colder air falls. This natural occurrence, known as convection, facilitates air movement and is also the main principle used in central cooling equipment.
Various forms of insulation can help you control the temperature inside your home without overworking your cooling systems. The less insulation you have, the more you use your air conditioning to regulate indoor temperatures, and that’s bad news for the environment as well as your energy costs. You’re using more fuel, and generating more carbon dioxide. Insulation is a process that can help you reduce both.
Your home can’t win against the heat on its own. Do you have proper insulation to help you? Here’s a tip: start with your roof. We discuss why in Part 2 of this series.