Fractal Design Define 7 Compact - Airflow Question

Been planning to add more case fans to Hoshī (muh PC) for some a long time now. For completion’s sake, not for min-maxing performance. It’s just, prices for Noctua Chromax fans kinda suck. :rofl:

I know Arctic and be quiet! and Noctua Reduxes are a thing. But, uh, kinda set on Chromax fans, 'cos Hoshī has a NH-D15 chromax.black chonki boi and I need consistency.

So… Planning stages? And double-checking. Opinion-seeking. Or something.

Will be sitting on my hands for forever a few more months waiting for prices to dip ever-so-slightly, feel free to chime in whenever. :sweat_smile:


Case: Fractal Design Define 7 Compact
(Mesh Top Panel)

Case Fans: 4 × 140mm + 1 × 120mm


Option 1: Intake > Exhaust
(Positive Pressure?)


Option 2: Exhaust > Intake
(Slight Negative Pressure?)

  • Option 1: Intake > Exhaust
  • Option 2: Exhaust > Intake
  • Option 3: Other

0 voters


Other Questions/Think Thonks

  • Only considered Options 1 + 2 'cos I’m uncertain if having one top fan as intake and the other as exhaust is a good idea. I remember hearing it isn’t?
  • Plan is to populate all(*) the case fan spots, with 4 × NF-A14 PWM chromax.Black + 1 × NF-S12A PWM chromax.Black. At full price, it’ll run me about $123.00. Open to other ideas, so long as they’re Noctua chromax.Blacks, lol.
  • Asterisk(*): Bottom is a rat’s nest of cables. Very much doubt squeezing an extra 120mm fan under all the cables there would help anything (would probably do more harm than good, lol), so not going to bother there. :sweat_smile:
  • Probably doesn’t matter, but CPU cooler is a Noctua NH-D15 chromax.black and graphics card is an ASRock RX 5600 XT (open-air GPU cooler).
  • …I did reach out to Noctua about potential discounts. Only way to get a “discount” is to purchase the fans off their noctua.at store site, review the product in accordance to their guidelines, wait for them to approve of whatever they see, then receive refund the discounted amount after all that waiting. Took one look at their guidelines and went, “Yeah, I can’t do that.”
  • Noctua’s bundles (Amazon Link) have been out of stock since forever.

…I could have posted this question on the LTT forums. Ehhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh… ¯_(ツ)_/¯

4 Likes

I kinda like doing front intake with top/rear exhaust, and then try to balance the flow between 'em.

It makes me happy inside and has worked for insert entirely too long timespan here.

4 Likes

Iirc you can have 3 intakes fans (but 120mm) at the front for a positive/neutral pressure. But option 2 is the best imo, the more “natural” way to set fans.

3 Likes

Firstly, offended I wasn’t tagged :joy:

Option 2 will be the better orientation. In some ways, flipping the top-front fan to intake could yield better CPU temps under load, as the top-front fan in exhaust will partially take the Front-Top fans’s nice cool intake air and just shoot it out the top before it even gets to the CPU cooler.

However, there’s a point of diminishing returns for performance and noise, and it usually hits at 2 intake and 1 exhaust fan. Going beyond that especially in a case where the two front fans are basically going right into the CPU+GPU already wont help cool too much and will definitely add noise. If you do decide to populate all fan slots, RPM tuning will be important, as ideally you want the same amount of air coming in as going out. IE; Two intake fans needs to spin fast to equal the amount of air three slow exhaust fans pull away.

Bottom fan definitely does nothing with a PSU shroud of this design and should not be used.

5 Likes

Hm, I’ve got a somewhat similar setup to yours (large dual tower heatsink, open air graphics card, Define R6) and I have settled on:

  • 3x 120mm intakes in the front (Noctua NF-F12s)
  • 1x 120mm intake in the bottom (Noctua NF-F12 chromax.black)
  • 1x 140mm exhaust in the rear (Noctua NF-A14 industrialPPC-2000 PWM)

For me, this seems to offer the best balance of cooling and noise.

Previously I also had the three 140mm stock Fractal fans installed (two in the top as exhausts, one in the bottom as intake), and I’ve found them to not offer any sort of improvement in terms of temperatures.

If anything, temps were a little higher than they are now, and I was also getting substantially more noise if I turned the fan speeds up (both because of there being more fans, and because of the Fractal fans being louder than the Noctuas).

The top exhausts I think did nothing but take away some of the air that was supposed to go through the CPU heatsink (particularly the fan closer to the front of the case), and the second bottom intake also didn’t help at all because of how restrictive the PSU shroud is.

The NF-F12 I’ve got in the bottom now is mounted as close as I could get it to the front of the case, where you should have an opening in the PSU shroud to let air through.

So… out of the two options you’re considering, I’d go with #2 - intakes in the front, exhausts in the rear and top. Top intakes don’t really make sense, so I don’t think that’d be a great choice.
However, I’d also consider ditching the top fans, and just going with two intakes in the front and an exhaust in the rear, since that’ll likely net you pretty much the same cooling performance, but with lower noise. Or that plus a bottom intake.

4 Likes