I replaced the cheapo electric pump that made a terible thumping noise for a Carter rotary vane one. The Carter is tall and it doesn't fit tucked into the frame like the old one. It doesn't look safe so I'll be extra careful with curbs! It is very quiet with humming sound when standing next to it. In the inerior there is no sound at all. There is no place to put it that sits lower than the tank, unless I make a brackets with hangers and those look so cheap from those I've seen. So I'll live with it.