Do Thermal Curtains Really Work?

Robert Anderson from Curtain Clean Wellington (The Wash House)

Curtains, particularly thermal lined ones, can reduce heat loss by as much as 60%, depending on the type of windows your home is fitted with. The key to ensuring you get the most out of your curtains is in understanding exactly how heat is lost, and how the use of thermal lined curtains can prevent this.

Understanding the physics: You know the old saying that hot air rises? Well, during cold weather that is exactly what happens, and something called the reverse chimney effect comes into play.

It is widely accepted that cold air is denser, and therefore heavier, than warm air. When it’s cold outside the air close to the window is cooled and sinks down (due to its density increasing with the temperature change). When the cooled air sinks it’s replaced by warmer air from other parts of the room.

As you can imagine, this then creates a circulating current, taking all of your warm air and replacing it with cool air. And just like that, you have lost most of your heat, not just near the window, but in the entire room.

If your curtains are not fitted correctly they form a channel between the window and the curtain, creating a space for the cooled air to sit and increasing the effect of the reverse chimney. The most important aspect to note is that it is the power of each factor combined, which decreases heat loss. No single factor works in isolation.

The first thing to ensure is that your curtains fit your windows correctly. This means that they are within a millimetre of perfect, with absolutely no gaps at the top or bottom. They need to fit against the wall snugly, creating a seal between the curtain and window.

Keep reading: www.curtainclean.co.nz...