plan to setup an outdoor aluminum sun louvers , may i know how long can it last?
can alum withstand sunlight heat & rain?
alternative material for alum if any?

as i know pure alum wont rust

so it won't corrodes due to sunray & rain?
coated or plain also the same?

pure alum wont rust even when you put them into salt water
but as for corrodes, it depends on to the design and also the thickness of it

roof ventilator is aluminium.. even the warranty is at least 10 years..

In terms of durability, aluminum sun louvers is still the best compared to timber or galvanised steel.

not sure if it could lasts 20yr for m'sia weather

the price is about 3x costlier then wooden blinds , i m still hesitating either to get louvers or blinds , any insight ?

how much were you quoted for?

I would go for the timber blinds as they're so
natural looking and cool [they dont heat up
as does metal & alloy].

Their lifespan in our weather depends on what
species is utilised. Hardwoods like chengal, balau,
belian and teak are top choice for outdoor hardiness.
Plus the grain is so attractive and soothing to the eye.

The end choice is up to you, good luck!