I specified wooden louvre blades
This louvre window installation is described in this earlier post.
Louvre now fitted with glass blades
The automated louvre window that I specified for my system of summer cooling by nocturnal purge had wooden louvre blades of western red cedar 14 mm thick.
I specified wood because I preferred that this louvre should not be transparent, as I did not want to see through it and I did not want it to admit light. I took the risk that wooden blades might not seal as well as advertised.
Other posters on the ATA forum (see link below) doubted that the blades would seal effectively. They were right.
Failure of the wooden blades to seal
When the louvres were closed for the first time, there was clearly no seal at all. The rubber seals fastened to the blades failed to meet the matching blades, leaving gaps of up to 2 mm admitting daylight.
Attempts to rectify
I wrote a letter of complaint on 18/5/2016.
Rectification work on warranty first revealed faults in the gallery of gearing at the side of the window. However, when the gallery was replaced the gaps remained. The photo shows daylight visible on the right side through three of the gaps.
Wooden louvres showing daylight
As the blades did not meet their specification, the company replaced them without charge. When these new blades did not seal any better, the company offered (on 10/10/2016) to replace them with aluminium blades, 6 mm thick. I reviewed the specifications of their blade options, and decided that this was not acceptable. The aluminium blades had little thermal resistance (U-value: 6.55). Glass blades 6 mm thick, with a low-e coating had much higher thermal resistance (U-value: 4.40), almost the same as the wooden blades (U-value: 4.39). The company agreed to provide these low-e glass blades. (In fact, this had been their original suggestion.)
Sealing of glass louvre blade gaps
The louvre opened
A daily chore in summer
My high-mass solar-passive house keeps me comfortable through the year with very little attention. I have detailed the actions I must take in this post. Being in BCA Climate Zone 4 “Hot dry summer, cool winter”, I have a summer regimen to keep the house cool, and a winter regimen to keep it warm. Most actions are required only twice a year: to change over from one regimen to the other. However, one action is required daily throughout the hot season: I must open doors each evening to admit cool air, then close them again in the morning. At night, air is drawn through the house and out the clearstory windows by the stack effect, assisted by fans at the windows. Warm air in the house is purged by the flow of cold night air, which continues to cool the mass of the house until sunrise.
My louvre vent project
[Photos, with descriptions, may be seen in carousel view here.]
Subsequently, I had to have the wooden louvre blades replaced with glass ones, as I describe in a later post.
I have put into effect a long-standing project to avoid the daily chore of opening and closing doors. I bought a motorized louvre window (Breezway Altair Powerlouvre Innoscreen) to let in the night air.
Louvre Time Clock
It is controlled by a programmable electric time clock (Hager EG203E) that will open the louvre at 21:00 and close it at 07:00 daily through the hot season. In the cold season the louvre will remain closed, with the motor control turned off.
The louvre closed
The louvre is installed low in a wall on the colder south side of the house. It is near the back door that I have been opening and closing up to now. It was difficult to find a place to fit it.
I thought of fitting a motorized louvre in the back door itself. This would have been awkward and expensive. Doubly so, because the back door opens into the laundry, which forms an air-lock, and the inner laundry door would also have needed a motorized louvre.
The kitchen was the only suitable room to admit the cooling air. Of course, it is almost completely lined with benches and cupboards. Eventually, I found a place for the louvre, and had a hole cut in the wall for it.
Louvre aperture from outdoors
Louvre aperture from indoors
The place I chose is partly behind the refrigerator. Continue reading