One way to approach this would be to have the filters appear as a modal. This would address two issues:
1) The user presses 'Done' or 'Apply' to close the modal, which gives them the desired confirmation that the search results have been changed.
2) Users won't have to scroll past a long list of filters to get to the results beneath. This can be a problem, particularly if the results are spread over multiple pages and navigating through them takes the user to the top of the page each time.
The attached images are from next.co.uk. Pressing the 'Filter' button causes the filters modal (second image) to slide up from the bottom, so the user knows it hasn't taken them to another page.
