External Rad at Window

Dirk Diggler · 25 Sep 2017 at 13:14

What's the consensus with external radiators at an open window, should they suck the cool air in or blow the hot air out? Would intake of cold air risk condensation?

Edit: this thread lead to me installing an external radiator in my garage, here's how it took shape...

First, it's some hammer action with the battery drill. I decided to forget the blank plates and just route from inside the right hand storage cupboard. I routed 2 hoses and also a signal cable for the PWM control of the fans.

Next, I bought some shelves from Homebase, a bargain at £20 IMO.

Now I've set the PC up so that I can remove the external rad and link the flow and return, so that I've got a stand alone PC should I need to move it to another room. I've also set the top rad in the case to ramp it's fans up should the rad in the garage fail to cool for any reason (PSU trip or whatever).

I then stuck some swivel 90 fittings on and connected up the external hoses.

Now, I hook the hoses up to the external radiator. I've made it so that I can easily disconnect at the radiator and drain if I need to, and I've stuck a 600w EVGA PSU in there to power the 4 fans.

All up and running, so on to some tweaking for temperature etc..

Afterwards, I decided to fit a little bypass and then mount the radiator properly.

Next, I boxed it all in and applied some insulation to make it snug. I've installed an anti-condensation heater and a frost stat.

Finally, I've installed a little flap on top that will keep the heat in if it's Brrr.. and this will lift up automatically to let the hot air out when the fans ramp up to 100% when gaming.

Now I just need to monitor the numbers and tweak accordingly. My OCD is now at bay.

Dirk Diggler · 25 Sep 2017 at 14:42

VKleita said:
I'll see if i can get you a couple of piccies later if you wish.

Yes, that would be good, cheers.

I've rearranged everything because whilst my loop is nice and cool, my room was almost 30C with the heat after a good gaming sesh. It sounds like I need to go with air pushing out towards the window.

Dirk Diggler · 25 Sep 2017 at 20:45

@pastymuncher interesting setup.

My cave is actually an office and backs on to my garage which is integral to the house, so a brick wall separates the two rooms. I was toying with the idea of drilling a hole for the tubes to go through and then mounting the radiator in the garage, but I thought the Glasgow winter would see the fluid getting so cold that I would risk condensation inside the PC.

Maybe I could configure the pump to go to minimum flow when the water temperature gets really low?

Dirk Diggler · 26 Sep 2017 at 09:38

pastymuncher said:
You will need three holes in the wall, 1 each for inlet/outlet and another for the fan wiring.

I'm thinking of putting a metal face-plate on the wall (like a socket but blank) and drilling two holes to accept bulkhead fittings. I can then simply screw the tubing from the PC on to the face plate, which would allow me to repeat in reverse if I had to remove the PC for maintenance etc.. I could also mount a brush face plate next to it for the cables.

Dirk Diggler · 26 Sep 2017 at 11:24

@VKleita to keep things sealed I could use a simple flex outlet face plate. I'll need to do a bit of planning here, but definitely think the rad in the garage would be a big improvement and worth the effort.

Dirk Diggler · 26 Sep 2017 at 15:13

Yea, I'll take some photos as I go and keep you updated, although it's a month away before I start the cave/office refurb project.

Here's a couple of pictures of how it is just now, with the rad pointing to the open window for some hot air exhaust action.

Dirk Diggler · 2 Oct 2017 at 06:26

What's the temperature Delta for condensation to form if the assumption is air inside the PC is at 25C? I've been Googling but not getting anywhere. I assume the volume of water in the system would be a factor also?

Dirk Diggler · 2 Oct 2017 at 18:02

@VKleita I agree it doesn't appear to make sense but maybe we're missing something?

Actually, rather than put the rad in the garage, I'm now toying with the idea of putting the entire PC in the garage and bringing the cables through to the cave. That way the risk of condensation is gone and I am guaranteed not only low temperatures but absolute silence!

Dirk Diggler · 25 Oct 2017 at 19:33

Progress has been made (eventually):

First, it's some hammer action with the battery drill. I decided to forget the blank plates and just route from inside the right hand storage cupboard. I routed 2 hoses and also a signal cable for the PWM control of the fans.

Next, I bought some shelves from Homebase, a bargain at £20 IMO.

Now I've set the PC up so that I can remove the external rad and link the flow and return, so that I've got a stand alone PC should I need to move it to another room. I've also set the top rad in the case to ramp it's fans up should the rad in the garage fail to cool for any reason (PSU trip or whatever).

I then stuck some swivel 90 fittings on and connected up the external hoses.

Now, I hook the hoses up to the external radiator. I've made it so that I can easily disconnect at the radiator and drain if I need to, and I've stuck a 600w EVGA PSU in there to power the 4 fans.

All up and running, so on to some tweaking for temperature etc..

Dirk Diggler · 25 Oct 2017 at 21:25

Dirk Diggler · 25 Oct 2017 at 21:38

samcat said:
You dont need to use a dedicated PSU, simply get a 12v wall wart with enough amps for the fans.

Could you link to one of those?

Dirk Diggler · 25 Oct 2017 at 22:29

@samcat thanks, I'll add that to my project list of things to do.

Dirk Diggler · 26 Oct 2017 at 12:14

This is what I've used: https://www.overclockers.co.uk/ek-water-blocks-ek-cable-splitter-4-fan-pwm-extended-wc-9cq-ek.html

...although I've had to daisy chain a couple of 4-pin extensions from the motherboard fan header. This lets me control the fans according to the water temperature. I think this will help with any risk of condensation as I can have the fans go to minimum speed if the fluid goes under 20C which effectively has the components heating the water back up. I've also set the internal rad fans to be off until the fluid temperature hits 40C, which obviously it should never do (it's just a fail safe).

Having the internal rad fans off not only contributes to a silent system, but I found last night that the internal rad was working like a little fridge by blowing the cold air from the fluid into the room! Essentially, the internal rad is a backup that under normal circumstances acts as a passive cooler.

Air temp in garage right now is 10C, and the fluid temperature is 19C, so my little system appears to be working. When the fluid reaches 25C the external fans ramp up to 100% and this results in a max GPU temperature of around 35C.

So far, so good :cool:

Dirk Diggler · 26 Oct 2017 at 12:50

samcat said:
As its in the garage you could run the fan profile starting at 50% and ramping up quite quickly.

I've got it starting at 20% right up until 20C, and then it ramps up to 100% at 25C which is the biggest step available. I want it at minimum speed as I don't want the fluid getting too cold. It's pretty much a passive cooling system until the GPU starts to work.

Hope that makes sense.

Dirk Diggler · 26 Oct 2017 at 13:36

samcat said:
Perfect sense.

Whatever works for you.

Does the garage ever get below zero?

I'm pretty sure it will during winter as I'm in Central Scotland. It can get as low as -20 in these parts.

Dirk Diggler · 26 Oct 2017 at 14:16

Ah! I didn't think about that. I only use Mayhem's Ultra Pure with a silver kill coil. What would you recommend for an additive? I can't use XT1 as it creates a cloudy substance due to the EK hard-line PET-G.

Dirk Diggler · 26 Oct 2017 at 22:22

I've dropped @Mayhems a note regarding advice on the correct additive to use with the water.

X1 clear looks like it may do the trick: https://www.overclockers.co.uk/mayhems-x1-clear-premixed-watercooling-fluid-1l-wc-035-mh.html

Dirk Diggler · 26 Oct 2017 at 22:26

samcat said:
You cannot rely on heat from the rig solving it, as what if there is a power cut or you shut the pc down..

Just thinking about this too, could I install a second pump in the garage that is set to run constantly off the dedicated PSU? This would mean when the PC is shut down the water is still flowing? What would be the result if the internal pump was running at minimum speed and the external pump was running at maximum speed, would they adversely affect each other?

Dirk Diggler · 27 Oct 2017 at 08:46

Temp dropped to 2C last night, fluid temperature dropped to 14C. :eek:

@VKleita @pastymuncher are you guys using additive in your loop?

Dirk Diggler · 27 Oct 2017 at 18:32

I've ordered a 750ml bottle of X1 clear concentrate. I've also ordered a 40w thermostatic tubular heater.

Might as well get this done properly.