What to do about an inverter with noisy fans?

[ar2301]

I've installed 8 x 600W panels on my roof and a Powmr 6.5 kW hybrid inverter along with 10 kWH of lithium 48v batteries in a storage room of my small concrete off-grid house.

Everything is working great, but the noise from the inverter's fans when there is even a tiny load is extremely annoying and can be heard from anywhere in and around the house. The storage room currently has no ventilation and the weather is often 30-40c outside, so it gets pretty toasty in there.

Any suggestions?

Some ideas I've had, but not really happy about any of them:
1. Replace the 60mm inverter fans with something quieter (might still be too loud and/or not strong enough)
2. Remove the inverter's fans and rig up some kind of large external fans ducted into the inverter.
2. Add some vents to the room, possibly with fan(s).
3. Add a small air conditioner to the room (seems counterproductive to add extra noise and power use).
4. Build a shed for the inverters and batteries 50m away from the house down a hill (a lot of work and would require extending the PV cables 4x further)
5. Buy a much more expensive, passively cooled inverter (would probably still need better room ventilation).

 

[cs1234]

Is the room ultimately getting too hot for the inverter? Or is your concrete bunker building absorbing the heat well enough that it isn't just continuing to rise in temperature? If the temperature just rises forever, you have to remove the heat.

If the heat is under control, maybe you can just install some sound absorbing panels on the walls and door and see if that helps?

 

[ar2301]

> Is the room ultimately getting too hot for the inverter?

I'll need to test it some more. I just turned the system on for the first time today and don't have enough loads installed in the house yet to really stress it.

But that's a good point.. the concrete may dissipate the heat well enough over time. And luckily the house is mostly shaded.

Sound absorbing panels may be enough combined with quieter fans running at slightly slower speeds. But I'd guess the sound insulation would hurt heat dissipation as well.

 

[cs1234]

Sound absorbing panels may be enough combined with quieter fans running at slightly slower speeds. But I'd guess the sound insulation would hurt heat dissipation as well.

Possibly, you might only need the deadening materials on the portions of the room that directly connect to other living areas. Only way to find out it is to try it I suppose.

You might end up needing a combination of sound deadening and something like a box fan blowing on/across the dumb thing. A box fan with a temperature controlled on/off AC switch for it might be a relatively easy solution if it just needs more airflow.

 

[ar2301]

Maybe a crazy idea.. but what if I ripped out the inverter's fans, removed its case, and just pointed a large floor fan at it (inches away)? I wonder if that would at least match the original cooling ability. It would certainly be quieter.

Obviously I'd need to be careful with the exposed wiring, but it's a locked room to which only I have access.

 

[DIYrich]

3. Add a small air conditioner to the room (seems counterproductive to add extra noise and power use).

Minisplit. Noisy part is outside.

 

[Mattb4]

Maybe a crazy idea.. but what if I ripped out the inverter's fans, removed its case, and just pointed a large floor fan at it (inches away)? I wonder if that would at least match the original cooling ability. It would certainly be quieter.

Obviously I'd need to be careful with the exposed wiring, but it's a locked room to which only I have access.

Many of these units will go into fault if the internal fans are not working. From the sound of it you need a cooler mounting area for the AIO.

 

[cs1234]

Many of these units will go into fault if the internal fans are not working. From the sound of it you need a cooler mounting area for the AIO.

Easy enough to find out what it does with it's fans disabled, just disable them.

 

[cs1234]

Minisplit. Noisy part is outside.

I was going to suggest that, but we don't know the layout of his concrete bunker and how hard it is to run ac lines from this room to the outside.

 

[ar2301]

Many of these units will go into fault if the internal fans are not working. From the sound of it you need a cooler mounting area for the AIO.

AIO?

 

[cs1234]

Maybe a crazy idea.. but what if I ripped out the inverter's fans, removed its case, and just pointed a large floor fan at it (inches away)? I wonder if that would at least match the original cooling ability. It would certainly be quieter.

Obviously I'd need to be careful with the exposed wiring, but it's a locked room to which only I have access.

It might work. I have found that sometimes the smaller fans are much more effective at spot cooling particular trouble areas on the device than a box fan blowing across the whole open thing.

 

[cs1234]

AIO?

All-in-one.. the inverter is an all-in-one because of the integrated inverter, charger and mppts.

 

[ar2301]

I was going to suggest that, but we don't know the layout of his concrete bunker and how hard it is to run ac lines from this room to the outside.

I can just drill a hole in the outside wall. It wouldn't be too difficult.

I think I'll start by checking whether I can disable the fans. If yes, then try the box fan idea, if no, replace them with quieter fans that I can control. If the overall room temperature is a little too high, I'll add a passive vent to the room. If way too high, then I'll install a minisplit AC.

 

[cs1234]

I can just drill a hole in the outside wall. It wouldn't be too difficult.

I think I'll start by checking whether I can disable the fans. If yes, then try the box fan idea, if no, replace them with quieter fans that I can control. If the overall room temperature is a little too high, I'll add a passive vent to the room. If way too high, then I'll install a minisplit AC.

That sounds like a logical flow of ideas to test.

 

[DIYrich]

If the overall room temperature is a little too high, I'll add a passive vent to the room.

When 40c outside, passive or active vent won't help.

 

[cs1234]

When 40c outside, passive or active vent won't help.

Depends on how hot it is in that room.

Clearly the equipment will already be unhappy running in a 40+ C room.. but maybe he doesn't want to try getting them into a room that is in the 20's C.

 

[Mattb4]

I can just drill a hole in the outside wall. It wouldn't be too difficult.

I think I'll start by checking whether I can disable the fans. If yes, then try the box fan idea, if no, replace them with quieter fans that I can control. If the overall room temperature is a little too high, I'll add a passive vent to the room. If way too high, then I'll install a minisplit AC.

I would check your manual and see if there is a fan failure fault code. If there is no point in taking things apart.

 

[ar2301]

I would check your manual and see if there is a fan failure fault code. If there is no point in taking things apart.

You're right, there is a fan fault error code in the manual.
I would think it shouldn't be too difficult to trick in into thinking the fan is there.. maybe just add a resistor?

 

[cs1234]

You're right, there is a fan fault error code in the manual.
I would think it shouldn't be too difficult to trick in into thinking the fan is there.. maybe just add a resistor?

It might just continue running with a fan failure error code anyway.

 

[Mattb4]

It might just continue running with a fan failure error code anyway.

Depends what the manual says. On my units it says it affects operation.

 

[Crowz]

You can buy a fan eliminator to fake the fans if you want. They sell them on amazon.

They are called fan simulators. I have them for some of my cryptominer machines. Google fan simulator on amazon.

 

[ThaiTaffy]

They don't get any quieter from my experience the Powmr units don't alter fan speed depending on temp or haven't in my case all I can say is over time you get used to it or I'm going slightly deaf.

 

[Tulex]

My inverter vents out the top, so I put a server rack fan on top to help pull the air through.
It draws next to nothing and is pretty quiet. I run them at less than half speed.
My inverter fans were cycling on and off even without PV, now they only come on when I have high PV. I can turn the rack fans up to prevent that, but I don't mind hearing them once in a while. I'd rather have a quieter constant fan noise with the rack fans.

These are what I purchased

 

[ar2301]

They don't get any quieter from my experience the Powmr units don't alter fan speed depending on temp or haven't in my case all I can say is over time you get used to it or I'm going slightly deaf.

The speed of mine definitely changes, possibly using some combination of temperature and load. At very low load, it's almost inaudible with the door closed, but > 100 W and it sounds like a jet engine. After 5-10 minutes of no load, it gradually winds down again.

 

[OffGridForGood]

40c is too hot.
if you have batteries in the same room 40c is much too hot.
look for methods to make the equipment room cooler - even running air through a set of ducts in the earth and back to the room can lower the temperatures considerably - but not easy to retrofit into existing space.
Maybe combine two ideas: "build a bunker 50 meters away" & sound insulation with minisplit.
ie build a new equipment room with sound insulation separating it from the existing building, put all the solar equipment in the new room, and cool that room with a dedicated minisplit to moderate the temps for batteries and inverters to run properly/safely. - doesn't need to be "50 meters" away just isolated from the rest of the building, put a door from the exterior to the new electrical room.