The external blower on our Onyx does not sound happy this season. Sounds like a bearing is going bad, or something. Do I send this one back for repair/replacement, or look at other options? I believe it's an 8" ~650cfm blower. There are tons of inline fans out there, and I wonder if some others might be quieter? Thoughts? For instance, I've pondered ~200 cfm 6" fans mounted out where the bedroom lines tree off.