External heater core placement – My plan, your ideas

megalomando · 10-14-2003, 12:39 PM

Greetings,

I’ve just purchased a 2-342 aka CGI 399090 heater core from Auto Zone and before I head off making what I think is the best mounting idea I thought I’d describe what I’m intending on doing. I intend to mount it on the back of the PC with the fan in-between the PC with the cooler fan blowing the air away from the PC.

Perhaps someone with personal experience can help shed light before I do this.

1. Radiator: The 2-342 has a ¾” outlet the bottom. It’s a single pass heater core designed with the 5/8” inlet at the top, outlet on the bottom. I am going to cut the tubing to extend out only 1” from the radiator with a dremel tool and then solder a copper pipe reducer to give me a ½” outlet on both sides that I can clamp hoses to. If I can’t find the reducers I will solder ½” brass nipples to the inlet & outlet.

Does it matter if I have the hot water entering the cooler at the top or bottom? Someone mentioned having the hot enter the bottom and the cool at the top with a single pass radiator. As it’s a one way flow path and the water doesn’t make a “U” turn before leaving the radiator as happens in a 2 pass radiator, the dynamics must be different. I was thinking if the hot entered the top & since heat rises that it would help pool the hot water at the top thereby delaying the hot water passage and only the coolest water would exit the bottom.

2. Fans: I plan to either use two 120mm fans or one large fan that will be as large as possible to fit The 9.5 x 6.125 x 2” radiator. It seems as if one large fan would make less noise than two smaller ones and it would be able to generate more than ample CFM. I will control this fans speed by any of several means depending on if it’s DC or AC.

Anyone know a large fan 6” in diameter that is quiet & powerful?

3. Fan shroud: I plan to make this out of solid pressboard (like the pressboard with holes to mount tools onto a garage wall). I will use dabs of epoxy to hold the pieces in place and then use silicone caulking compound on the inside to make it pressure tight. I plan to mount the fan 2” from the heater core. I will run a bead of silicone around the heater core and shroud to seal off any place to leak the pressure so 100% of the air will all go through the heater core. I will surround the heater core’s sides with this same pressboard for “looks”.

4. Fan safety: I will make a grill out of ¼” hardware cloth and attach it on the exposed side of the fan.

5. Grill safety: I will use the same ¼” hardware cloth and attach it to the exposed side of the radiator so as to prevent it’s fins from being dented.

6. Radiator/fan attachment to the computer: will be done via three long threaded bolts attached to the computer and the heater core’s upper & lower collection plate (the non-finned part where the inlet & outlet are). Two will be attached at the top of the heater core and one in the middle, not two at the bottom so as to not interfere with peripherals coming & going from the computer. I will first attach the heads of the bolts to the radiator core with JB weld and hold the tips of the bolts in place with a template having the same locations as the heads of the bolt so once dried, the bolts will line up straight. If a 4th attachment looks feasible I will add the 4th support but the 3 should be plenty strong by themselves

I will then make the computer attachments by making three mounting holsters using two ¾” “L” brackets with screw holes & JB welded side to side so as to make a “C” or “Z” shaped bracket as needed. I will drill holes in the case & bolt one side of the bracket to it or if necessary, JB weld each of these to the computer. I will thread a nut ½” up onto each bolt and then run the tips of the bolts into the hole in the bracket. Then I will add another nut and tighten the bolts to the Z or C bracket.

My idea is to keep the heater core out of the case because I believe the presence of a heater core in the computer just adds to the ambient temp and this method will allow for me to have the best cooling.

I would expect having the fan/radiator in the case would quiet the noise of the fan somewhat but the additional fans needed to cool the case would add to the overall noise. It seems to me as if using one large external radiator fan or two quiet duty 120mm radiator fans would allow for a much quieter overall noise level.

Have you any opinions on this placement & method? I’d like to hear them before I embark on this and I’d like to start construction asap.

Thanks

bigben2k · 10-14-2003, 02:47 PM

Click on the link to heatercore, in my sig.

There's your 6" fan

and a mounting solution.

megalomando · 10-14-2003, 07:47 PM

Quote:

Originally posted by bigben2k
Click on the link to heatercore, in my sig.

There's your 6" fan and a mounting solution.

Hi bigben2k,

Thanks for the reply!

All I could see for a fan is the blower in the case. Maybe I missed it along the way but I will be needing some kind of muffin fan, I've got a blower inside my ham radio amplifier & I don't want the sound of something like that coming from my computer

Besides, I do want to locate the heater core outside the case

winewood · 10-14-2003, 08:46 PM

.http://forums.procooling.com/vbb/sho...&threadid=8117

I used a transmission cooler. It is flatter, and better looking IMHO.

Quote:

Anyone know a large fan 6” in diameter that is quiet & powerful?

Have you attempted to use some 2 smaller fans you know will be quieter? The only reason I didn't use a fan blowing air from inside the case... its hotter, and if the case isn't well ventillated, the pressure will slow down the airflow.

Quarter · 10-15-2003, 01:18 PM

I'd suggest feeding the rad from the bottom inlet and having the top outlet as the return.
This will help to keep air from getting trapped in the top of the rad cap.
You could also tap an outlet on the top cap to add an air bleeder.

megalomando · 10-16-2003, 01:02 AM

Winewood,

Thanks for the reply. I did end up getting 2 120mm fans today. I tried the 6" they had and it was really nice but it was a bit noisier than I was willing to go with.

I decided against the transmission cooler because it's going to be either aluminum or stainless and they don't transfer the heat as well. OTOH, they probably do every bit as good as another core for what we want to do and they really do look nice.

Quote:

Originally posted by Quarter
I'd suggest feeding the rad from the bottom inlet and having the top outlet as the return.
This will help to keep air from getting trapped in the top of the rad cap.
You could also tap an outlet on the top cap to add an air bleeder.

That's an interesting thought. I remember on my old Chrystler wagon I'd start it & hear gurgling (had a tiny crack in the head) and then after running the heater a few seconds it would dissappear.

The mechanic said it was because the heater core was the highest part of the cooling chain & that's where bubbles would gather. running the heater flushed them out.

I wonder if the velocity the water passes through the core with is enough to flush them out?

But... you offer an interesting thought. I need to get some other opinions on this before I make my rad installation mods permanent. (Which was... going to be tomorrow...) Thanks for the thoughts

Quarter · 10-16-2003, 01:59 PM

The velocity through a single pass rad will be less than a more restrictive dual pass design of the same size.

Given a big enough pump, you would force the air down through the core, but why fight it if you don't have to.

There is no cooling advantage of feeding the warm water in at the top.
In fact, due to convection, feeding warmer water from the bottom could help a little in optimizing the flow through the system.
It may not be a lot, but every little bit helps.

10-14-2003, 12:39 PM	#1
megalomando Cooling Neophyte Join Date: Oct 2003 Location: Indiana Posts: 12	External heater core placement – My plan, your ideas Greetings, I’ve just purchased a 2-342 aka CGI 399090 heater core from Auto Zone and before I head off making what I think is the best mounting idea I thought I’d describe what I’m intending on doing. I intend to mount it on the back of the PC with the fan in-between the PC with the cooler fan blowing the air away from the PC. Perhaps someone with personal experience can help shed light before I do this. 1. Radiator: The 2-342 has a ¾” outlet the bottom. It’s a single pass heater core designed with the 5/8” inlet at the top, outlet on the bottom. I am going to cut the tubing to extend out only 1” from the radiator with a dremel tool and then solder a copper pipe reducer to give me a ½” outlet on both sides that I can clamp hoses to. If I can’t find the reducers I will solder ½” brass nipples to the inlet & outlet. Does it matter if I have the hot water entering the cooler at the top or bottom? Someone mentioned having the hot enter the bottom and the cool at the top with a single pass radiator. As it’s a one way flow path and the water doesn’t make a “U” turn before leaving the radiator as happens in a 2 pass radiator, the dynamics must be different. I was thinking if the hot entered the top & since heat rises that it would help pool the hot water at the top thereby delaying the hot water passage and only the coolest water would exit the bottom. 2. Fans: I plan to either use two 120mm fans or one large fan that will be as large as possible to fit The 9.5 x 6.125 x 2” radiator. It seems as if one large fan would make less noise than two smaller ones and it would be able to generate more than ample CFM. I will control this fans speed by any of several means depending on if it’s DC or AC. Anyone know a large fan 6” in diameter that is quiet & powerful? 3. Fan shroud: I plan to make this out of solid pressboard (like the pressboard with holes to mount tools onto a garage wall). I will use dabs of epoxy to hold the pieces in place and then use silicone caulking compound on the inside to make it pressure tight. I plan to mount the fan 2” from the heater core. I will run a bead of silicone around the heater core and shroud to seal off any place to leak the pressure so 100% of the air will all go through the heater core. I will surround the heater core’s sides with this same pressboard for “looks”. 4. Fan safety: I will make a grill out of ¼” hardware cloth and attach it on the exposed side of the fan. 5. Grill safety: I will use the same ¼” hardware cloth and attach it to the exposed side of the radiator so as to prevent it’s fins from being dented. 6. Radiator/fan attachment to the computer: will be done via three long threaded bolts attached to the computer and the heater core’s upper & lower collection plate (the non-finned part where the inlet & outlet are). Two will be attached at the top of the heater core and one in the middle, not two at the bottom so as to not interfere with peripherals coming & going from the computer. I will first attach the heads of the bolts to the radiator core with JB weld and hold the tips of the bolts in place with a template having the same locations as the heads of the bolt so once dried, the bolts will line up straight. If a 4th attachment looks feasible I will add the 4th support but the 3 should be plenty strong by themselves I will then make the computer attachments by making three mounting holsters using two ¾” “L” brackets with screw holes & JB welded side to side so as to make a “C” or “Z” shaped bracket as needed. I will drill holes in the case & bolt one side of the bracket to it or if necessary, JB weld each of these to the computer. I will thread a nut ½” up onto each bolt and then run the tips of the bolts into the hole in the bracket. Then I will add another nut and tighten the bolts to the Z or C bracket. My idea is to keep the heater core out of the case because I believe the presence of a heater core in the computer just adds to the ambient temp and this method will allow for me to have the best cooling. I would expect having the fan/radiator in the case would quiet the noise of the fan somewhat but the additional fans needed to cool the case would add to the overall noise. It seems to me as if using one large external radiator fan or two quiet duty 120mm radiator fans would allow for a much quieter overall noise level. Have you any opinions on this placement & method? I’d like to hear them before I embark on this and I’d like to start construction asap. Thanks

10-14-2003, 02:47 PM	#2
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	Click on the link to heatercore, in my sig. There's your 6" fan and a mounting solution. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

10-15-2003, 01:18 PM	#5
Quarter Cooling Neophyte Join Date: Aug 2003 Location: San Diego, USA Posts: 15	I'd suggest feeding the rad from the bottom inlet and having the top outlet as the return. This will help to keep air from getting trapped in the top of the rad cap. You could also tap an outlet on the top cap to add an air bleeder.

10-16-2003, 01:59 PM	#7
Quarter Cooling Neophyte Join Date: Aug 2003 Location: San Diego, USA Posts: 15	The velocity through a single pass rad will be less than a more restrictive dual pass design of the same size. Given a big enough pump, you would force the air down through the core, but why fight it if you don't have to. There is no cooling advantage of feeding the warm water in at the top. In fact, due to convection, feeding warmer water from the bottom could help a little in optimizing the flow through the system. It may not be a lot, but every little bit helps.

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