Drupal's Search Lucene API module is a nice alternative to Drupal's core search if you need more power and features (like facets, ...) but don't want to maintain a Solr installation. The Search Lucene API module comes with facet support out of the box.
One facet you will probably provide most of the time is the "Node type" facet. This allows your visitor to filter search results by content type. When you are using Panel nodes (provided with the Panels module), one of the options for your facet is "Panel". Unless all your visitors are Drupal people, they have no idea what a panel is (in this context). Most of the time, panel nodes can be considered as "pages". So conceptually, they are on the same level as "Page" nodes.
Using the hooks provided by Search Lucene API module we can add an extra field to our Lucene index, called "Clean type" and provide a facet for this field. This way we can add one filter option, called "Pages" which actually returns "page" and "panel" search results.
What follows is a snippet you can use in your own module.