Are the Any-Grid PSW-H’s fans loud? When do the fans run?

The Any-Grid PSW-H fans are always running. However, they are running at a reduced speed when the inverter is pushing low power.  When the inverter is converting low power, the fans will run at about 30% speed and will ramp up in accordance with the output power or the PV input power—it will take the higher of the two and immediately change the fan speed depending on the power—so they always run but they are speed-controlled. The fans are definitely loud in the sense that you will probably not want to mount this in your living room. This is something for the basement or a separate room. Also, because typically in most countries it is not even legal to be in the same room as the batteries, especially for lead acid batteries where you will have hydrogen coming out of the batteries which needs some ventilation, etc. So we would definitely not recommend having this in your sleeping quarters or your living room. The fans will always be under 60 dBa. When running at 30% fan speed the noise is roughly 35 dBa.