Louvres long used in hot humid climates
Louvre windows are popular in places with hot humid climates, where heat discomfort, due more to high humidity than to high temperature, persists day and night. Louvres, which have a larger area of opening than other windows, freely admit breezes to cool people in the house.
Louvre windows have not been popular where summers are very hot and dry. There, daytime breezes are too hot, and must be kept out. Louvres could be opened at night to let in cool air if they were fitted. They seldom were, because most louvres would not keep the house cool when they were closed. They conducted heat freely (high U-value), and leaked hot air in large amounts.
New louvre windows have effective seals?
Recently, manufacturers have claimed that their louvres "...seal tightly to give the best performance possible...". If that is true, then louvre windows can play a part in the design of low energy houses to be built in places with hot dry summers. They can be opened automatically on summer nights to purge the house of hot air. At all other times they can be kept closed to seal the house against outside air that is too hot or too cold.
For use only for ventilation at night, louvres need not have transparent blades. Wooden ones provide more insulation that any kind of glass.
Something to discuss?
I have not found any discussion of the use of louvre windows for night-time heat purging where summers are very hot and dry. In "Warm House Cool House" (1995), page 42, Nick Hollo mentions a house near Melbourne where "[cool] air is drawn into the house through controllable vents below the bedroom windows". So it has been done, a generation ago.
Does anyone have experience using louvres in this way?
My night purge louvre
I have now had an automated louvre window installed solely to admit cold air on summer nights. The job was not finished before autumn, but the system does operate. I have thermometers set up to find whether there is better cooling.
I have described my louvre set-up, with more photos, on my blog. Later there will be analysis of its performance.
https://climatebysurly.com/2016/07/04/louvre-window-for-summer-nights/