DIY fix for cold air flows around curtains: A reader’s letter

I remembered a mention of the heat lost in many homes by the ‘reverse chimney effect’ of standard curtains (drapes), especially inside ranch-sliders and full-height windows. And a simple method of fixing the heat loss involved.

The reverse chimney effect is the air movement between glass and curtain because of cooling. Warm air which floats to ceiling level is cooled at the glass and flows down in the gap to re-enter the room at floor level.

Standard curtain fittings are as if designed to encourage this flow by reason of the large gap at the top where the fitting is mounted on 75mm brackets, and the slot at the bottom where curtains usually end some 25-60mm above the floor.

Given a sturdy set of steps, a few household tools and a give-it-a-go attitude, it is well within the handy person's capability to fix this, allowing about two hours for the first window and a half hour for subsequent ones.

In my case, the only trick to learn was to turn the little plastic clamps which are located just below the metal brackets through 90 degrees, that is in line with the metal tube rail which is then free to fall down.

Next I pushed the plastic clamps back toward the wall to free them from the bracket. I left the bracket attached to the wall – in case there might be a problem with the process and I needed to restore everything to normal.

I then turned the rails end-for-end so that the slot for the slides was now exposed and facing in to the room. I replaced the plastic clamps and offered the rail back to the window architrave – the wooden trim above the window. It fitted flush against the timber with the clamps on top and ready to be screwed down into the timber.

Rehanging the curtain involved reversing the plastic hooks/sliders, tedious but easy. Job done (by an 86-year-old) so anyone can do it.

PS. In the process the curtains were lowered about 50mm to touch the floor, closing that channel also.