Can I noindex the filter result URL's?
If you would prefer to prevent search engines from crawling these URL's then you can do this using the 'robots.txt' file on your website.
To prevent search engines from indexing the filtered pages, you can add the following directive to your "robots.txt" file:
User-agent: * Disallow: /*_wcf_filter=true
This tells search engines not to index any pages that contain the
_wcf_filter=true parameter in the URL. This parameter is used in all the filtered results.
Here are some resources on how to edit the robots.txt file: