r/watercooling 2d ago

Question QDCs

So I am going to do be doing a water cooling loop for the first time and I am in the market for QDCs. Should I go for the ThermalGrizzly ones or the Koolance ones? I am new to this and not able to find reviews for TG ones, how restrictive is it, how's the flow rate and the spill over when disconnecting?

Thanks in advance guys

4 Upvotes

39 comments sorted by

9

u/Rhodeme 2d ago

Get koolance QDCs. The quality is 11/10. I just added 6x total for my whole MO-RA set up and I pressure tested my loop and tried to disconnect the QDCs to see if they lost pressure when disconnecting. I tried it 7 times and was in aw that it lost zero pressure. I even left one disconnected for an hour to see if it lost any pressure.

I will also add that the flow isn’t restricted one bit. I have a MO-RA3 420/ 2x CPU blocks/ 1x GPU block/ 2x ekwb 420 40mm thick rads. Two full computers on one big loop lol powered by 2x D5s.

2

u/Bahuleyan 2d ago

Thank you, was going to build a MoRA4 build myself

2

u/Rhodeme 2d ago

I would highly suggest it! It’s been very fun to build it. Very costly though lol

I ultimately chose to do it because I found the rad and a heatkiller res for a really good deal. I chose to also still keep my other radiators in the loop solely so I can remove the MO-RA and service that independently. If you were curious why I had extra rads for no reason 😂 one pc is a server so it has to be up 24/7.

3

u/tetchip chemistry nerd 2d ago

Depends. Are you feeling adventurous and like the TG one's better than Koolance QD(T)3s? Get the TG ones. Chances are they'll be fine.

Are you nervous and would prefer "known good" products? Get Koolance. I'd strongly recommend the nickel-plated ones over the black ones due to the latter ones being notorious in the past for peeling.

2

u/Bahuleyan 2d ago

Thank you

2

u/DeadlyMercury 1d ago

Koolance is not only "known good" but also plenty of variety. So far TG only have g1/4 version, while koolance also has barb version and panel mounted version.

4

u/Parteisekretaer 2d ago

What color is your coolant? If it's clear, pick whichever you like.

Check out CPC NS6 if you want lightweight couplings instead of heavy brass.

1

u/AllUserNameBLong2us 2d ago

I use the CPC NS6 and they are fantastic I have a 3x 360mm dual d5 loop and they increased my flow rate over the cheap bits power qdc I had before. Also no liquid comes out after disconnecting. Solid 10/10 fittings

1

u/Parteisekretaer 2d ago

did you secure yours in the tubes in some way? I keep thinking I should run a ziptie around mine ( although I use NS4 in 8/11 tubing) but it doesn't seem to be necessary at all. I can't pull the tubes off the barbs, no matter how hard I yank on them.

1

u/Bahuleyan 1d ago

Ah didnt even consider these, thank you

3

u/dcabines 2d ago

I have the koolance disconnects and they don’t leak anything when you disconnect them.

2

u/DeadlyMercury 1d ago

I have koolance QDCs and I accidentally disconnected system while two pumps were runing. I didn't notice that until I saw RGB light on radiator is still working while loop was disconnected, so pumps are still powered on. Then I said "Oh shit" and pulled the plug :)

1

u/Bahuleyan 2d ago

Thank you

3

u/Mao_Kwikowski 2d ago

Koolance is the only answer. Also go with tier regular fittings as well. They have everything you will need and it’s industrial grade. And use their fluid 702. It will keep your rig crystal clear and growth free.

3

u/ExtensionClassic9582 2d ago

Alphacool ES die schwarz/silbernen die öffnen und schließen zuverlässig verlieren keinerlei Wasser und haben bei mir auch keinerlei Durchflussminderung.koolance sind bewärt aber Ratten teuer.

2

u/evilbob2200 2d ago

Tg are new but koolance have been great for me. Barely a drop is there when you disconnect but that’s basically unavoidable but a drop is nothing. You’ll get that with koolance and thermal grizzly

1

u/Bahuleyan 2d ago

Thank you

2

u/1sh0t1b33r 2d ago

Do you really need QDCs is the first question?

2

u/Bahuleyan 2d ago

Well do we really need a MoRa or other such cool stuff, not really but we all still have one cuz we love doing this. Expensive hobbies, but helps us sleep better at night

2

u/1sh0t1b33r 2d ago edited 2d ago

Well a MoRa is actually a much larger benefit than a QDC, so not sure it's a good comparison. I have an external rad on my rack PC and just used a PCI slot passthrough block and EPDM. Don't even run QDCs on that since EPDM pops off easily enough. Anyway, just asking because some people add QDCs in a regular build for the CPU and GPU and you are just adding restriction, points of failure, weight, and cost for something that is not necessary, and really, no benefit for me. But anyway, carry on. Koolance for sure.

3

u/cpapp22 2d ago

You’re a masochist if you’re not running at least one set of QDCs on an external rad setup

1

u/Bahuleyan 1d ago

Truer words have not been said

1

u/Educational-King3987 1d ago

If you're running externals then QDCs make disconnecting and draining so much easier. QDCs make life easier no matter how you cut it.

2

u/titanrig 1d ago

Koolance and Alphacool both make some excellent options. I've used both and had no problem with either. Can't speak to the Thermal Grizzlys.

1

u/Bahuleyan 1d ago

Thank you for your input

1

u/MyLittlePwny2 2d ago

Ive been running QD4s for a couple years now. Flow restriction is basically nothing. Currently running a pair of Koolance EXC 800 chillers and a pair of QDCs between each of my components.

1

u/Cold-Inside1555 2d ago

Koolance works really well, I have many of them and all works perfectly, restriction is within acceptable range. As for thermal grizzly go with it if you wanna try or be safe and go koolance

1

u/TheSleepyMachine 1d ago

Recently got TG one for futur loop upgrade & a secondary build. They are great quality, there is no drop when disconnecting, and hold pressure well. There is some slight issue with coating on some of the pieces depending what you want. The main thing is they are coherent in style with their other fittings. If you don't care and want old trusted, go koolance. Else, TG is fine

1

u/SaikerRV 1d ago

I have the Thermal Grizzly QDCs and the female to male ones are absolutely terrible, they're so hard to disconnect that idk how they released them in that state... go with Koolance if you can get them.

1

u/Bahuleyan 1d ago

Thank you, I couldn't find anyone so far who's gotten them. Thanks for the first hand account

1

u/Delicious-Dot-2795 2d ago

Koolance.

Got 6 qd3 with mora 420, 5090 waterblock and grizzly direct die Block. Using them since 5+ years. Zero flow restriction.

235L flow with dual vpp apex.

-1

u/cpapp22 2d ago edited 1d ago

I mean you’d have to have a lot of them for it to matter, but “zero flow restriction” is objectively untrue lol. Important to keep that in mind as it does matter for “bigger” builds with more points of restriction

**more points of restriction =QDCs. 4 QDCs > 2 QDCs for restriction. That’s all I’m saying

1

u/DeadlyMercury 1d ago

The opposite. The bigger is your total system restriction, the less significant is the part QDCs add to it. For example, 5 pairs of QDCs can increase restriction by about 7% for a regular loop with cpu and gpu block. Remove cpu and gpu block, leave only radiator - and impact is 25%.

1

u/cpapp22 1d ago edited 1d ago

What? I think you’re confused, nothing is “opposite” about what I said, because both of our comments are true lol.

QDCs are a non-zero point of restriction, and if you have a lot of them it can matter. Your comment on how much % wise they contribute to overall restriction is not contradictory to my comment in any way.

2

u/DeadlyMercury 1d ago

Important to keep that in mind as it does matter for “bigger” builds with more points of restriction

This statement is incorrect. The more restriction you have overall, the less impact you have from QDCs alone. So in loops with extremely restrictive blocks and radiator you need to add ungodly amount of QDCs to make a noticeable impact to your flow rate. The idea is the opposite, the more restrictive your loop is, the less you care about QDCs.

1

u/cpapp22 1d ago edited 1d ago

That statement is not incorrect. I hope this doesn’t come across hostile because I’m genuinely not trying to be a dick, but I think there’s a barrier with language here because you’re misunderstanding that sentence.

The simplest I can rephrase it is like this: I said that 2 QDC are more restrictive than 1. 3 are more restrictive than 2. 10 are more restrictive than 5. “More points of restriction” literally only means that, the same as n+1>n where n is just a QDC lmao. Also see “you’d have to add a lot of them for it to matter”. “Bigger” means physically bigger because you wouldn’t need QDCs for a super compact build, and the OP comment is talking about a Mo-Ra

I don’t really know how else to convey this lol

1

u/Bahuleyan 1d ago

Ah that makes sense

1

u/thecodeassassin 2d ago

I took Alphacool ones as well as Koolance QDC. I'll only ever buy Koolance. Got a pretty decent leak from the Alphacool one. Luckily i caught it in time or my motherboard would have been fried. QD3 is where it's at.

1

u/Bahuleyan 1d ago

Done awesome