Where was that cold breeze coming from? I could feel it around my feet and legs while sitting in the lounge room. So could everyone else. Not a strong breeze by any means, just a gentle wisp now and then, but definitely there and definitely cold.
I checked the window but it was closed, the bubblewrap insulation that we installed earlier in the year (see here) on the bottom half was intact and the heavy curtains were protecting the room pretty well. But that didn’t explain the breeze nor did the slight amount of air leaking around the weather stripping on the front door (which I will have to upgrade as well). The other window was sealed and protected.
Then we noticed a breeze near the door to the kitchen but it was coming from above! That’s when I had the AHA! moment. I had forgotten about the clerestory windows. Well not quite forgotten so much as stopped remembering that they were on my to-do list. I had put off working on them because it was a bit inconvenient since they are 5 metres off the ground. But it had to be done, and it had to be done now because I had to return the extension ladder to my mate next door the next day.
We have two sets where we have cathedral ceilings in the lounge/dining area and in the family/kitchen area. I tackled the set in the family room first. Because they are at the highest point in the ceiling they lose a lot of heat because the warm air rises. So insulating these should have a significant impact.
Armed with a few cleaning cloths I climbed the ladder and started cleaning the filth that had accumulated from the bugs and condensation. I could feel the cold from the windows quite easily.
Once the windows were clean I checked the measurements and cut out some bubblewrap for each of the windows. Even though one of the windows can open, and we do open these to help vent hot air in summer, I decided to just staple the bubblewrap up against the frame and sort out a more permanent solution later in the year.
I also decided to use two sheets of bubblewrap (with the bubbles facing each other to increase the airgaps) on each window to increase the insulation effectiveness. As soon as I put the bubblewrap on the windows the effect was amazing. The cold just stopped! It was even more dramatic than the windows at ground level.
When I climbed back dwon the ladder everyone commented that that they could feel the difference. I’m not sure how much was psychological but that’s not a problem either. Perception is important.
Once I had done the second set in the lounge room the effect was definitely noticeable and the room felt noticeably more comfortable. It will be interesting to see over the next week or so whether this has indeed fixed the problem.
So glad I put the effort into climbing up there to do the job.