[fan] More control over HDR fan

[Black Hole]

Remember that the system will warm up quicker without the fan, so 1.75 hrs may be a little too long. The normal fan operation must also override this setting (as I assume it will), in order to to cater for the case if the PVR is turned off briefly after running for say, 1.74 hrs

Have no fear, the fan package establishes a porch level; if the normal system demands a higher setting, it gets it.

 

[af123]

Have no fear, the fan package establishes a porch level; if the normal system demands a higher setting, it gets it.

Assuming I get my < and > the right way round! : )


Posted on the move; please excuse any brevity.

 

[Ezra Pound]

I have manually changed the Fan setting from minimum = 0% to minimum = 40% after 1.75 Hours and the hard disc still never got hot enough to enable fan full on

 

[Wallace]

Agreed. The fans in both my HDR's is set to 49% (strangely, when I set to 50% the next time I view the settings, it's dropped to 49%). Neither fan has run at full speed since! The temperature is pretty much a constant level, ambient temp. not withstanding.

 

[Black Hole]

(strangely, when I set to 50% the next time I view the settings, it's dropped to 49%)

Some kind of difference between the way inputs are translated to output, then the actual value is read back for display, probably rounding errors. The percentage has to be converted to a 0-255 value, and then the 0-255 value back to a percentage.

If 0% = 0 and 100% = 255, output = input x 2.55 with some kind of rounding.

It's a bit sloppy if the conversions do not produce the same result though!

 

[Wallace]

In the grand scheme of things, it's not important. But it did have me checking myself a couple of times!

 

[xyz321]

I really think a timer is not the answer. What happens if the box is rebooted after an hour, does the timer restart even though the internal box temperature is now higher than ambient?

If the fan should remain off until the HDD temperature has reached a set level then the fan control should keep monitoring the temperature and adjust the fan speed accordingly. Basically it should perform the same task as the Humax currently does but with an improved control algorithm.

This would allow the fan to remain off until it becomes close to the set temperature and then maintain that temperature.

 

[Trev]

This would allow the fan to remain off until it becomes close to the set temperature and then maintain that temperature.

You mean rather than let the HDD get up to roasting then switch the fan on full? I can't see why you would want it to work any other way to that which xyz has it! Are we not trying to stop the HDD getting what is in our opinion, too hot? If so then surely it's the HDD temp that is the deciding factor, not some arbitrary period of time.

 

[Ezra Pound]

xyz123 : Yes that would be better, It would mean that at start-up the fan package runs /mod/bin/smartctl /dev/sdb -A every few min.s until the hard disk temp. shows say 50 Deg. C then applies Fan minimum, where 50 Deg C is settable

Trev : Are we not trying to stop the HDD getting what is in our opinion, too hot?

No, 55 Deg. C is not too hot, I though the aim was to not allow the fan to be on full in order to prevent the extra noise it makes

 

[petrev]

A better algorithm would be nice.

This is what happens to mine set at 50%


In my case:
OFF until [45]C then [50]% may give about 1hr silence before fan cuts in at pretty silent anyway (!)

Some may want something like that ? Mine seems good with current system.

EDIT: Kinda what Ezra posted while I was faffing !

 

[Trev]

I was referring to this,

I'd like to be able to use the box with no fan for the first hour or so. Unless of cause it's needed. Be nice to be able to set the length of time from start-up to wait until it overrides the fan.
That would be the best of both worlds.

and the standard operation of the fan.

I though the aim was to not allow the fan to be on full in order to prevent the extra noise it makes

Agreed.

 

[Black Hole]

I don't understand the problem. In the worst case, the fan will do exactly what it has always done. Using CF to set a porch level satisfies people who want to push a bit of air through in the expectation of limiting the ramping up and down. Adding a delay before it cuts in should be easy enough, and again in the worst case the fan does exactly what Humax decided it should do. Anything more complicated becomes an unnecessary overhead and risks interfering with the Humax safety algorithm. It is also very difficult to design a satisfactory algorithm when there are large delays in the control loop.

Personally, I do not see the need for a delay - the idea is that the porch level fan speed is set at a compromise between cooling efficiency and noise (and the noise should be less than the noise of the HDD at low fan speeds) - but would be another knob to twiddle for the dedicated fiddlers until they realise zero delay is the best setting.

 

[Ezra Pound]

Although I broadly agree, a delay (I would favour temperature rather than time) will cut down on overall revs. which I think will be increased by having say a 40 - 50% minimum from start-up, we would have to count revs to prove it but my guess is that a 40 - 50 % minimum from cold will add up to more revs than the Humax algorithm

 

[free30]

Thanks for this.
...
That would be the best of both worlds.

and the standard operation of the fan.

Not quite.
It would allow it to turn on for a recording for a hour with no fan, but expecting temp rises would aim to avoid high temp by turning the fan on after a set time.
Anyhow I'm a happy either way, or is that, the more I get the more I want

 

[G4DDS]

I have been using this package for several weeks (with it set at 50%) and via the system monitoring tool I could see that the temperature was consistent after the box had been on for an hour or so and the fan never ran at full speed.

I am currently on holiday (abroad) and so that I could have a wide window for me to logon to the box and see what it was doing I set a on timer for 10AM and off timer for 4PM. Since Monday (which was the first day the on/off timer was in operation) the system monitoring tool indicates that the fan has gone back to its old behaviour i.e. the temperature ramps up, the fan kicks in at full, the temperature drops, the fan speed drops until it goes off and then the temperature ramps up again, the fan kicks in at full etc.

Interestingly, the night time recordings where the unit is powering up from standby also appears to indicate that the fan package is not working. I have not done anything to the box or its setup other than to set the on/off timer.

Any ideas why it has stopped working? Obviously it is limited to what I can do as I will have to do it remotely.

 

[Ezra Pound]

By viewing the system monitoring >> hard disk temperature >> 5, 10 and 30 day graphs you can at least tell when the pattern of fan cycling changed and see if it ties up with a change of usage, say adding the 10am-4pm timer etc. It would be possible to force a re-install of the fan package but it would be good to find out why it stopped

 

[G4DDS]

By viewing the system monitoring >> hard disk temperature >> 5, 10 and 30 day graphs you can at least tell when the pattern of fan cycling changed and see if it ties up with change of usage, say adding the 10am-4pm timer etc.

Slight correction - the off time is 6PM (not 4PM). I set the power on/off timer late Sunday night and the graph shows that it was fine on Monday (10AM to 6PM) and the standby recordings that took place Monday night but then from Tuesday onwards it starts playing up.

 

[Black Hole]

Check what the settings page says, that it is still where you set it.

I installed fan for the first time yesterday, put it to 40% and my units settle within a degree of 44C.

 

[G4DDS]

Check what the settings page says, that it is still where you set it.

I installed fan for the first time yesterday, put it to 40% and my units settle within a degree of 44C.

Web interface says it is set to 49% (but its actually 50% as per the discussion you guys have already had concerning the interface reading back 1% difference).

The fact it worked on Monday and I have not changed anything since due to the fact that I flew out on Monday morning has me puzzled.

 

[Ezra Pound]

I presume you are only getting system monitoring graph readings for the 10am to 6pm period with no results for other times, I ask because if you are getting graph results continuously, that would show that the HDR isn't going into standby properly