The reason why there is no comma between the adjectives is that the adjectives in your sentence are so-called cumulative adjectives - meaning that they do not modify independently (i.e. separated by a comma). So, no comma between them.
One way to help recognize when/ when not to use commas is to place the word 'and' between the adjectives and see if the sentence still sounds right.
Let's see here:
We have a spacious and well-ventilated library. / an equipped and computerized library. (still sounds correct; so, no comma between the adjectives)
The man who stole my wallet is a dirty and rotten scoundrel. (now sounds wrong)
It should be a comma between the adjectives: he is a dirty, rotten scoundrel. (sorry for this example)