In article ,
Derek ^ writes:

I only started thinking about it at 23-30pm last night when my little
Chinese weather station told me it was 26c inside the house and 16.6c
outside. Thinking at the time that running a ventilation system
overnight might result in the house starting the day cooler, bearing
in mind that hot clear sunny days tend to be followed by clear cool
nights.

Not passive but a fan and a "smartbox" of electronics could make a
worthwhile improvement and be better for the environment than air
conditioning. On a smaller scale it could be applied to a larder where
most probably the whole lot could be solar powered.

I have an alternate loft hatch cover which gets put in place in the
summer, which has a rather large fan in it to draw air through the
house and expel it through the loft (also cooling the very hot loft).
It is under the control of my home automation system. I haven't
actually spent much time working out the optimum rule for switching
it on, but it currently switches on when the loft reaches 25C.
I often switch it on manually in the evening too to draw in the
cooler nighttime air.

--
Andrew Gabriel