Ok, short and sweet. If someone is going to be tampering with an expensive piece of equipment then they need to have at least a basic understanding of what went into the design of said products. If not - don't mess with the innards.

Learn what needs to be learned then dig in. Just picking up bits and pieces from forums is not learning. Not a bad start, just you better verify technical details and concepts presented. Forum answers are mostly A=B without the how's and why's. Now you know why typical air movers won't work. Bet you will remember it too.

You want a Forum geared to instruction, go to Instructables.com
Seriously, I do highly recommend it. Great site.

And no doubt the miner is reset to it's default IP addressing. Don't remember if the s4 defaulted to a static IP or was DHCP. I think it is DHCP so you will have to look at your router to find the miners new IP address.

Key point you missed:
My emphasis on 'free air'.
Why time and again must it be bought up that the densely packed configuration of miners from s7 on up ALL produce substantial resistance to airflow? You know - high back pressure aka Static Pressure? Having to push air against that back pressure is why the fans used in Ants and yes even the Avalons are so loud. It is just the nature of the beast.

Free-air flow ratings of any fan/blower are useless specs for cooling miners and relying on them will always result in very poor real-load performance. Fans/blowers useful to miner cooling will specifically mention using against high back pressure and give a Static Pressure rating usually in Inches of Water or a metric version of that.

Changing power demand is not the point. The OP wants to reduce noise and a squirrel cage blower can be extremely quiet while delivering high airflow against sizeable back pressure. Of course most run directly off the AC power line.

Think furnace blowers. One with a 1/4hp motor works out to around 300w of power and will probably push well over 1-2k CFM against the back pressure 4-6 miners would have. Since each fan on a s9 pulls a bit over 24w, that's 50w of fan power for the 1 miner. Makes using around 300w to quietly cool several miners look rather good if ya want to make shelves & ducting to do it.

Love it and makes for a great post # 2,000 for me

As with all the other applications, since the business is paying for power anyway to make the needed heat it would be to their advantage to offset the energy cost by mining. Say use the miners to supply around 75-80% of the heat needed and use a conventional heat source to provide the rest. That way miners stay running 24x7 and temp control is done by the conventional heater & temp controls.

Ah. That aspect has been extensively covered and recovered and recovered in other threads... Ya the heat could be reused in many areas needing a constant moderately to very warm temp. Quick re-cap:
Hydronic heating
Baking (proving rooms)
Food preservation (beef jerky)
Pools/spas

No, you got it right. The most common USB3.0 ports and hubs can provide a little more current than 2.0 allows but folks have had issues running sticks directly from 3.0 hubs. Since we don't care about the higher speeds 3.0 can run that leaves main requirement as...

The need to simply use a hub that will supply more 5vdc power such as ones rated for 2.1A and higher charging. Look for BC2.1 as  I recall. They are normally used to power tablets/phablets and the better ones will happily provide more than just 2.1A -- but -- look at how many ports and which ports it can feed that power to at the same time.

Technically you *can* mine BTC with a CPU/GPU but for the past few years the income will be near zero because any ASIC rig even from 2-3 years ago is far faster. In fact most BTC mining pools probably will treat it as dust and not even allow that primitive of a miner to run on them.

To OP, no this is not the right place. This section is for Bitcoin hardware only.
Alt-coin Q&A belongs here : https://bitcointalk.org/index.php?board=160.0

Well this is a T9 thread so...

Considering the s7 family uses a different ASIC chip and CPU I highly doubt the T9 will run and you very well might brick it...

Well, I pointed my gimpy R4 batch-6 (only 1 board working) at the pool last night and it's running just fine there at the same speed KanoPool reports which is 4.8THs. Considering chips & firmware are pert-near identical, s9's should be fine. He's certainly made no comment as to what can and cannot be ran, if anything, the idea is for the pool to accept all miners no matter how fast or slow, big or little.

Um, click on the 1st blue link you see on the page... It translates to http://ckpool.org/pool/ .....

That ^^ looks rather nice and good to see they are not using Novec
Tried to dl the FAQ on their thermal xfr fluid but must be one helluva big PDF -- over minute and still not loaded. That's a 'FAQ'?
Too bad and rather stupid that they won't talk to 'small' users...

Nice start of the day! 3 blocks under our belt and I got the 1st one hgt 462536. 'Twas on a s9 ta boot.
That makes my 4th on Kano

So then post in the *hardware* sections of the forum....
And lose the 'in bed with Bitmain' train of thought. You will find very few here fitting that idea.

Or mount a proximity sensor or photo-cell near the blower wheel to pick up the blades as they go by. Great airflow and still have fault detection

By Jove yer right. Just looked at the s1 manual. Top they show is 250GHs, lowest is 150 so the uc had to have been at the low end. No matter what, Terminus smokes them

Sweet. Terminus full tilt is about the speed I think was running my s1's at the end of their lives, they were down clocked to 175-225GHs. Bet it takes what, 1/4 the power?

Ja. Mining MUST be looked at over the long term so the uber-fast and ultra-slow blocks even out..
As in at least several weeks at a time when testing what pool is 'Best'.

Been there, done that (testing, compiling spread sheets) several times and gotta say for me, KanoPool has always been best when looking at total payout over at least 1 month time.