In very broad terms, each ajax request takes the same amount of “effort” by the server to process like a full page load. From this perspective, 30 AJAX requests instead of one page load sounds like a very bad idea. It all also depends on the frequency those requests are being “fired”, if it happens every second it is bad, if only when a user does some action, it might not be optimal, but not the end of the world.
Of course, if this is a requirement, it can be solved by using a stronger web server, which in an intranet enviroment should not be a very expensive idea.
What you should do in any case, is to try to minimize the number of requests, for example by combining several of them.