Have had this installed for a few months. Installation was straightforward and operation is good. It's a solidly built unit. This unit though is very loud. I thought my previous Sirius unit was loud, but this one puts that to shame. It sounds like the wind blowing across the frigid Tundra. I did reach out to Z-line for suggestions and they told me to flip the filters around. This made a noticeable difference because the whistling stopped, but overall the noise level didn't not diminish. With one or both of the filters removed the unit is silent. It's definitely the design of the filters. It would be nice if another filter option was available.