Active inverter cooling question/problem.

[Brucey]

By monitoring the temperature.

My inverter is inside, so is not exposed to environmental conditions.

After looking at it during full load conditions, I've ascertained the newer fans are performing at a similar level.

Of course it gets used at full load.

Manufacturers put these fans in so they know it will be cooled. Full stop. It means cooling issues are completely out of the equation.

They use cheap nasty ones that are overkill.

My inverter sat at 26c with the stockfans.

It now sits at 30c with noctuas.

So same noise.

Yeah return them asap for some quiet ones.

You can't just put an ultra quiet fan in some of these AIOs. They have garbage cooling designs and require high static pressure fans. So it's very much inverter model dependent.

 

[Kid Solar]

You can't just put an ultra quiet fan in some of these AIOs. They have garbage cooling designs and require high static pressure fans. So it's very much inverter model dependent.

Of course you can.

Don't replace junk with junk.

Use a high quality fan.

There are fans with 3/4 CFM and static pressure with about 1/10th the noise output.

Mine has gone from 70db to 18db.

Temps have risen from 26C to 30C under load.

 

[Brucey]

Of course you can.

Don't replace junk with junk.

Use a high quality fan.

There are fans with 3/4 CFM and static pressure with about 1/10th the noise output.

Mine has gone from 70db to 18db.

Temps have risen from 26C to 30C under load.

Which inverter did you quieten from 70dB to 18dB?

 

[Kid Solar]

Which inverter did you quieten from 70dB to 18dB?

Growatt SPF 5000 ES

Noctua NF-A8

 

[fmeili1]

In the meantime I've received the two weather sensors and I've installed one at the very right side of the inverter (the closest to the mini split) and one on the very left side of the inverter with the longest duct distance to the mini split.

AIO closest to the mini split:
The following chart shows the temperature of the closest AIO (upper red line), the garage ambient (blue line - mini split inlet air temperature) and the cooled air temperature at the end of the duct before entering the AIO (orange). The pink rectangle line shows the chosen cooling setpoint settings of the mini split. The dotted black line is the humidity of the cooled air.


AIO furthest away from the mini split:
The following chart shows the temperature of the furthest AIO (upper light blue line), the garage ambient (blue line - mini split inlet air temperature) and the cooled air temperature at the end of the duct before entering the AIO (purple). The pink rectangle line shows the chosen cooling setpoint settings of the mini split.The dashed black line is the humidity of the cooled air.


The closest AIO to the mini split sees about 12°C lower temperature compared to the ambient and the furthest AIO about 8°C lower temperature (longer duct distance losses).

The relative humidity of the cooled air varies between 35 and 50%.

Here is the chart with all 6 AIOs (the six upper lines are the six AIO temperatures via SolarAssistant):

The cooling setpoint rules for the mini split are able to keep the AIO temperatures below 45°C (max. AIO temperature is while max. PV production at noon with about 14.2kW (after noon my batteries were full and PV was clipping and PV power reduced) with 8 strings distributed over 6 AIO MPPT entries - 4 MPPT's are not used yet).

The lowest cooling setpoint for the last 24h was just 4°C below ambient to maintain the AIO temperatures below 45°C.

While the mini split is just set to 1-4°C below inlet temperatures with lowest fan speed, it hoovers with relatively low energy consumption (unfortunately I don't have it's exact power consumption values).