Is this original equipment or added?

[sdflysurf]

Started hearing a grinding noise, traced it back to this unit that seems to have a fan/motor/bearings/something that is rotating inside.  The black tubes you see seem to be going to behind the instruments but not connected (just ventilation/circulation maybe).  Since the previous owner had it in the desert as his home base, maybe he added it himself for that reason? 

Looking in the POH I can't find this.  I will look through the log-books and report back.

Was this original equipement and tubing or added?  Is it required to be replaced if it fails?

The other picture included shows the black tubing connected into the co-pilot side air intake.

[Shadrach]

Likely a cooling fan for the avionics. What year and model is your plane?

[sdflysurf]

1968 M20F

[N201MKTurbo]

It appears to be an avionics cooling fan.

[ArtVandelay]

It appears to be an avionics cooling fan.

Shouldn’t the 2 ports without hoses be capped off?

[N201MKTurbo]

It is a Bendix King KA20 cooling fan. 

5 minutes ago, teejayevans said:

Shouldn’t the 2 ports without hoses be capped off?

It would probably work better if they were. If it isn't hooked to anything I would remove it.

https://www.dmktuoutlet.top/bendix-king-ka20-avionics-cooling-kit-fan-pn-071403100-p-5801.html

 

Edited November 23, 2018 by N201MKTurbo

[sdflysurf]

Ok I agree it is an avionics cooling fan, it does seem to be that bendix-king-ka20, considering the other two hoses are just routed and open on the ends, the two ports that aren't connected to a hose seem to be properly pointed at the co-pilot side avionics so no need to put any more tubes.

Do you guys think this is original equipment and so it must be replaced?  Is it best to have an avionics cooling fan/system even in moderate climate?

[Shadrach]

36 minutes ago, sdflysurf said:

1968 M20F

Definitely not stock.  If those tubes go to nowhere, I would take some time to verify that your radio stack is properly ventilated. 

[sdflysurf]

7 minutes ago, Shadrach said:

Definitely not stock.  If those tubes go to nowhere, I would take some time to verify that your radio stack is properly ventilated. 

Thank you.  Since it isn't stock I'll just INOP it and look for a new system to replace it with when I upgrade my avionics over the next few months.  Currently the usable radios/avionics are properly ventilated.  There are a couple of units that are old/bad and are being replaced (King KR-86 ADF and an old King KNS-80)

[Shadrach]

3 minutes ago, sdflysurf said:

Thank you.  Since it isn't stock I'll just INOP it and look for a new system to replace it with when I upgrade my avionics over the next few months.  Currently the usable radios/avionics are properly ventilated.  There are a couple of units that are old/bad and are being replaced (King KR-86 ADF and an old King KNS-80)

In Stock form there is a  NACA duct on the right side of the fuselage that provides fresh air to a diffuser on the radio stack.  Good luck with your radio install!

[ArtVandelay]

Is there any modern avionics that requires external cooling?

[takair]

3 hours ago, teejayevans said:

Is there any modern avionics that requires external cooling?

Yes....many do recommend (if not require) external cooling.  Not always required, but improves reliability.  The back of the rack usually has an inlet to attach the 1” hose.  While power supplies have improved, the backlight, higher power processors, and delicate components still prefer to be well ventilated. 

[N201MKTurbo]

4 minutes ago, takair said:

Yes....many do recommend (if not require) external cooling.  Not always required, but improves reliability.  The back of the rack usually has an inlet to attach the 1” hose.  While power supplies have improved, the backlight, higher power processors, and delicate components still prefer to be well ventilated. 

My Avidyne 550 will burn your fingers in the summer.

[carusoam]

The hose appears to be from the 60s...

Unless you are cooling 60’s radios... you are cleared for the approach to change out the old fan with a new one... and use some modern sceet/scat/ or whatever the proper hose is...

For research go to the Aircraft Spruce site... look up avionics cooling fans...

PP thoughts only...

Best regards,

-a-

[DualRatedFlyer]

1 hour ago, N201MKTurbo said:

My Avidyne 550 will burn your fingers in the summer.

Do you have external cooling for this?  My 440 gets pretty warm as well. Always wondered if I'm shortening it's life by not having supplemental cooling for it. 

[N201MKTurbo]

1 hour ago, DualRatedFlyer said:

Do you have external cooling for this?  My 440 gets pretty warm as well. Always wondered if I'm shortening it's life by not having supplemental cooling for it. 

No, but I should.

[Guest]

I’ve mounted a small computer cooling fan under the panel and raised the glare shield to promote air circulation behind the panel.

Clarence

[Yetti]

On 11/23/2018 at 4:49 PM, teejayevans said:

Is there any modern avionics that requires external cooling?

Ipads.   Samsung does not suffer the similar fate.

[ArtVandelay]

Ipads.   Samsung does not suffer the similar fate.

Only if exposed to sunlight or you have insulated cover.