Personally, I don't see what the fuss is about. These things use forced air to cool. Whether it blows up or down is irrelevant. Why natural convection is even a topic when there is FANS is something I don't get. Are we going that say that along the height of the inverter, the air at the top of the inverter is really that much hotter than the bottom? Over some 40/50cm of height?

Are we really going to say the 40/50cm height difference is significant in a room that is ventilated etc. Isnt there more effective ways such as better room cooling that can be done than worry about a 40/50cm temperature increase (if there is at all, I would be surprised if it is even 1 degree)?

If one reverses the fans, are you not just sucking all the dust from the floor now?

Regardless, are we going to say the 90% of the population that is not technically inclined and never touched their Axperts fans and reversed them never got more than 5 or 10 years out of them because of this "design flaw"?

Edited April 17Apr 17 by Denns

47 minutes ago, Denns said:

Personally, I don't see what the fuss is about. These things use forced air to cool. Whether it blows up or down is irrelevant. Why natural convection is even a topic when there is FANS is something I don't get. Are we going that say that along the height of the inverter, the air at the top of the inverter is really that much hotter than the bottom? Over some 40/50cm of height?

Are we really going to say the 40/50cm height difference is significant in a room that is ventilated etc. Isnt there more effective ways such as better room cooling that can be done than worry about a 40/50cm temperature increase (if there is at all, I would be surprised if it is even 1 degree)?

If one reverses the fans, are you not just sucking all the dust from the floor now?

Regardless, are we going to say the 90% of the population that is not technically inclined and never touched their Axperts fans and reversed them never got more than 5 or 10 years out of them because of this "design flaw"?

From the heat that the inverter itself generates, maybe (thumbsuck) as much heat as from a 60W incandescent light bulb or a candle, I'd say the logical thing is that air above the inverter should be hotter than below, since that hot air inevitably will be rising upwards.

What this thread is questioning, is whether you should position the fans to work with the natural rising airflow, or against it.

28 minutes ago, GreenFields said:

From the heat that the inverter itself generates, maybe (thumbsuck) as much heat as from a 60W incandescent light bulb or a candle, I'd say the logical thing is that air above the inverter should be hotter than below, since that hot air inevitably will be rising upwards.

What this thread is questioning, is whether you should position the fans to work with the natural rising airflow, or against it.

I do agree with you. But I question if the air is that much hotter. The fan pulls air from the sides, goes through the inverter, which is some 40cm in height and gets thrown downwards and while the hot air rises again, it is quite turbulent, and there is little chance, in my opinion, that the same hot air gets sucked in by the inverter as it rises. If the room is ventilated well enough, this should not be a cause for concern.

It was mentioned that the electrolytic caps are positioned on top of the inverter, so logically, by reversing the fans, essentially, the benefit of the cool air is seen by the components at the bottom section of the inverter, and now those caps are getting hit with hot air.

At the end of the day, what are the chances that the people who designed the inverters, if they had the brains and education to know how to build one. Miss such a critical thing that a hobbyist thinks they know better.

Has anyone on here actually measured the temperature inside different areas of the inverter with the fans running as from the factory? And then checked those same different areas inside the inverter after reversing the flow? What if the layout of the components inside the inverter was done in a way to cool the critical items with cooler air coming in from the top and hot air going out the bottom?

Unless one has a discussion with the designer and has empirical and quantifiable evidence that reversing the fans is actually better for the Axpert, I will remain sceptical.

I reversed the fans on my 48V 3kVa Plus model when I first read this thread and noticed that the fans definitely run more often and for longer than before. I have never actually measured temperatures and have not changed them back to standard (often thought I should but never get around to it) and have never had even a minor hiccup with the inverter in about ten years of offgrid use.

Edited April 17Apr 17 by dax021