How to keep pc clean like new?

I use hand blower since years and it works wonders
It is something like this:
https://www.amazon.de/Makita-MAKITA-Akku-Gebl%C3%A4se-Laubbl%C3%A4ser/dp/B00NLXXQXQ/ref=sr_1_57?ie=UTF8&qid=1483972240&sr=8-57&keywords=gebl%C3%A4se

I clean the PC outdoor...it is ok to have the dust flying around

The best way to clean your parts is to not let them get dirty in the first place.

You do this by setting up a positive pressure airflow situation.
That is where ALL of the intake air comes in from one source and is filtered.

With your case, it should be easy.
The 200mm front intake fan should supply all the cooling air you need for even a set of hot parts.
I do not know if your case comes with a washable front filter.
If it does not . buy or make one.

Whatever air comes in from the 200mm front fan will exit somewhere.

A single 120mm exhaust fan at the rear will serve to direct the airflow.

Adding more exhaust is counter productive.
A strong exhaust fan will draw in unfiltered air from adjacent openings.

In your situation, I would simply remove the two top 120mm fans .

As to cleaning, you probably need to use a slightly dampened cloth or paper to get the dust off.
Water is ok, or, if there is grease, dampen with alcohol and wipe things down.

The high pressure inside the case strategy only to make your PC clean longer than using the low/neutral pressure strategy.
Using filter is also only about slowing the cleaning frequency.
You still have to clean it one day.
I clean my PC once every 6 months.

Too much air out and not enough air in. Remember that intake air filter s can reduce air flow by as much as 30% ... and that while bigger fans are "bigger", they also run a lot slower. A well designed case will have inlet filters on all intake fan mounting locations so as to allow for radiator mounting where fans always blow in. Again, on a well designed case, this will include the top fan mounts so that the top mounting locations can be used as either intakes or exhaust.

If you know any young folks playing music in their garages, they prolly have a $29 fog machine. If you do, or want to but one you can test this out. Many folks get hung up on the "hot air rises" thing that we all learned in 8th grade earth science. But when you are in a closed environment and are introducing "air movers" (fans) into the equation, this goes "out the window" (pun intended). The air goes where the fans are pointing. In your case, I suspect that with the air inlet restriction and 3 fans blowing out, you have not only dust coming in the rear grille but also hot PSU and GFX card exhaust. I would suggest trying:

a) If your top of case has an air inlet filter, reverse the fans

b) If it doesn't buy some filter material
http://www.frozencpu.com/cat/l3/g47/c223/s1706/list/p1/Fan_Accessories-Fan_Filters-Filter_Material-Page1.html

Lacking a fog machine, while not as obvious or effective, you can test what's happening with cigarette smoke

As for what does get in .... I been using one of these for last dozen years or so.

https://www.walmart.com/ip/46555100

The intake capability of any fan is primarily a trade off between higher rpm and more noise.
Fans at 700rpm will largely be inaudible.
Over 1500 rpm, they will be noisy.
In between is the sweet spot.
At what rpm is your current 200mm intake running?
If it seems inadequate, you could usefully use a stronger intake.
Perhaps something in the 800 rpm range.
If you have a problem finding one, I would use a pair of 140mm fans running in the 1000 rpm range.
If you calculate out the intake area of either option, they will be about the same.

Since it is easy to simply remove the top two fans, why not try that out?
If cooling is unaffected you are good.

As to liquid coolers, I do not recommend them in a good case like yours.
The orientation of the radiator will cause a problem.
If you orient it to take in cool air from the outside, you will cool the cpu better, but the hot air then circulates inside the case heating up the graphics card and motherboard.
If you orient it to exhaust(which I think is better) , then your cpu cooling will be less effective because it uses pre heated case air.

Remember, liquid cooling is still air cooling.
The only difference is where the heat exchange takes place.

And... google "h100I leak"

Yes, unless you want to keep running with negative case pressure. Aslo, radiator fans should be exclusively air intakes. That's why I said if your case doesn't have one, you will need air inlet filter material. Have you read the directions for the proposed H100i ? See very 1st box on Install Guide"

http://www.corsair.com/~/media/corsair/download-files/manuals/49-000175_rev_ab_h100i_qsg_web.pdf

Attach the radiator and fans as shown. For the best cooling performance, we recommend mounting the fans as an air-intake into your PC Case.

Though I would strongly recommend against selecting the H100i which can't cool as well as several air coolers which are significantly less expensive. In addition:

a) By using a cheap aluminum radiator, the H100i's performance is significantly hampered.
b) Because if that it must use noisy, extreme rpm fans making it 12 times as loud as say the Noctua NH-D15 air cooler which cools better
c) By mixing aluminum and copper in the same loop, once the corrosion inhibitors in the coolant lose their effectiveness over time, galvanic corrosion will inevitably begin
https://martinsliquidlab.wordpress.com/2012/01/24/corrosion-explored/
d) You can not replenish inhibitors and algaecides because of the closed system
e) No visual indication of coolant flow.

Would strongly recommend using the Swiftech H series or ED Predator as they have none of these weaknesses.
http://www.swiftech.com/aio.aspx
http://www.ekwb.com/predator/case-compatibility-list/

With 2 in and 1 out, out will have pos pressure.... Turn on the top fan going out and you lose that. If ya can get over the "hot air rises thing, (it really doesn't when there's a fan ... ever sit under a ceiling fan ? ), the top fans blowing in will help, tho.

a) If your CPU cooler is installed w/ fans horizontal, blowing up don't have the fans fighting each other.
b) If your fans are blowing to rear on the cooler, this will work just dandy.
c) Make sure you case provides an air inlet filter to trap dust

I can't say that three fans will be enough ... follow this guide:

Take CPU wattage (when overclocked if appropriate) ... i7 is about 90 watts stock, 130 watts overclocked
Take GPU wattage (when overclocked if appropriate) ... 1070 is about 180 watts outta the box, 250 overclocked

Add 30 for MoBo and maybe 25 for everything else

130 + 250 + 30 + 25 = 435 overclocked
90 + 180 + 20 + 25 = 315 stock

If ya want things quiet ... Below about 850 rpm good fans are inaudible

For 120mm 1250 rpm fans you can use 75 watts (50 - 100) based upon how good a noise level you want) per fan ... I'd recommend 4 fans for a stock system
For 140mm 1250 rpm fans you can use 100 watts per fan (75 - 125) based upon how good a noise level you want) per fan ... I'd recommend 5 fans for an overclocked system

CM690 III has:
Front: 2 x 120 / 140mm fan
Top: 2 x 120 / 140mm fan or 1 x 200mm fan (optional)
Rear: 1 x 120mm fan (installed)
Bottom: 1 x 120mm fan (optional)
Vented slot covers

With that setup, using rear and top as exhaust doesn't work

Setting up relative strength of fans ....

120mm exhaust = 1.00 (75 watts)
120mm intake = 0.67
140mm intake = 0.91

=============================
Front: 2 x 140mm fan = 1.84 in
Rear: 1 x 120mm fan = 1.00 out

That set up will quietly handle about 213 watts (up to 284 at full rpm) and has positive pressure
=============================


=============================
Front: 2 x 140mm fan = 1.84 in
Rear: 1 x 120mm fan = 1.00 out
Top: 2 x 140mm = 1.84 in

That set up will quietly handle about 351 watts (up to 468 at full rpm) and has significant positive pressure

One wrinkle tho ... the case has vented slot covers but no real "rear grille".... do the slot covers provide enough ventilation to let the excess air out ? I can't say w/o testing that case w/ the fog machine, but I'd think so
=============================

If you run the top fan, either in or out, it will tend to draw in unfiltered air form an adjacent opening. Not so good if you want clean.
I would simply remove the fan to let air more easily escape. Quieter too without an extra fan.
Remember, all air that comes in from the front is clean air and it will exit someplace.

If your temperatures are nominal, do nothing else.
By nominal, I might expect while gaming perhaps 75c. under load for the cpu and 85c for the graphics card.
More than that, use higher rpm intakes in front. It will be at the expense of added noise.

1. When you have positive case pressure, drawing air in from "adjacent openings" would be in direct conflict with the laws of physics... in other words, it's simply impossible.

2. You make an assumption that is not based in fact and has been clearly detailed above. Most decent cases have air filters on top of the case... I can't speak to this case as I don't have it in front of me, but as has been stated twice in previous post.... if the manufacturer cheaped out and didn't provide, have to put it in yourself. You may also want to note that the relative air flow in the post directly included the reduced air flow as a result of the restriction from the air inlet filter on top of the case as having been originally provided or subsequently installed by user.

A well designed case will have inlet filters on all intake fan mounting locations so as to allow for radiator mounting where fans always blow in. Again, on a well designed case, this will include the top fan mounts so that the top mounting locations can be used as either intakes or exhaust.

a) If your top of case has an air inlet filter, reverse the fans

b) If it doesn't buy some filter material
http://www.frozencpu.com/cat/l3/g47/c223/s1706/list/p1/...

Click to expand...

That's why I said if your case doesn't have one, you will need air inlet filter material

Click to expand...

3. The air that comes in from a front filtered opening is no cleaner than the air from a top filtered opening.

4. Noise does in no way equate to number of fans. I have 16 fans in my case (10 radiator / 6 case) it is dead silent. Sitting next to it, you can't tell if the box is on of off; I have restarted it many times thinking it was off when monitor was asleep. Using a noise meter, I recorded background noise and then turned PC on ... same reading

One fan running at 1800 rpm is louder than 4 fans running at 650.

We test with 6 temperature sensors (0.1C accuracy) wired to a 6 channel digital display, an infrared thermometer and a fog machine. What you describe simply does not happen. With 4 filter equipped fans blowing in and 1 unfiltered blowing out, no fog will ever enter the case thru adjacent openings... no unfiltered air will get into the case cause all inlet points are filtered. 5 fans running at 350 - 850 rpm are quieter than 3 fans running at 1200 1800 rpm because under 850, they don't make any sound. Also remember that the flow restriction from air filters increases exponentially. So doubling the rpm means 4 times the air resistance which drastically reduces the actual air flow from the fans. More fans at lower rpm always wins over less fans at higher rpm from both an air flow and noise perspective.