Resolving Cooling Issues

Hello and welcome to the third instalment in my car computer project :).

As I mentioned in the previous post, the computer became very hot when running, so to combat this I have made a number of improvements to the cooling system. I removed the console and computer from the car, and until I receive all the parts I ordered for it, It won't be remounted. This will save me time and effort in removing the need to double handle the console as it is a two person job to fit it to the car.

Firstly I made a trip to my local electronics store and bought some heat sinks to augment the cooling of the computer's power regulators (MOSFET's), southbridge, and northbridge. The heat sink that I fixed to the southbridge came with thermal tape applied and it was a simple matter of peeling and sticking it on. Unfortunately it is a bit small, in hindsight I should have bought 4 for maximum cooling capacity.

Southbridge without cooler

Southbridge with cooler

 Installing the northbridge coolers was a simple matter of applying some thermal adhesive to the underside of the four coolers and then sticking them on to the top of the existing cooler.

Northbridge with coolers

I improved internal airflow in the case by making a few tweaks to the cable management. I also installed extra wires for manually powering on and resetting the computer. These will be wired up to a DPDT Carling switch later on. I used wiring salvaged from an old PC case, as it was already twisted together and had the female connectors installed, so I could plug them straight into the motherboard.

Computer before cable management; the extra MOSFET coolers aren't installed in the is photo.

The computer in its entirety. You can see the mounting tray for the SSD on the top left. 

Computer with cable management and extra wires for the manual power/reset switches ran out through the back. Note this photo was taken before the power supply cables were shortened.

The third improvement to the cooling system I made was airflow management. During initial testing I noticed that some of the air from the two 40mm intake fans was being blown backwards out the front of the case through two large holes for the hard drive and DVD drive. Since I'm not running an optical drive in the computer this is empty, presenting a path of lesser resistance for the air to exit the case, rather than flowing axially along and exiting out the exhaust holes to the rear.

Front panel of the case, the two 40mm fans have been removed until I receive the new high performance ones. The hole to the right is for the optical drive & hdd.

Looking at the picture above, air was flowing down through the two round holes and a large proportion of it straight up again through the two rectangular ones. Not very efficient at all. The solution I came up with was a simple one. I cut out a piece of thin plastic from some packaging, traced the holes onto it and cut it to size, making sure no screw holes were covered. Then I simply glued it onto the front plate.

Not the prettiest solution by far, but it should direct the air through the case, removing as much heat from the computer as possible.

The next tweak I made was to shorten the ATX power cables from the PSU to the motherboard. This will allow more airflow and easier reassembly of the computer, as the cables were getting caught as I slid the case over the tray.

Extreme cable management. Every cubic millimetre counts for airflow!

Aside from the cooling issue, other parts that I have ordered associated with the computer and console are arriving. I have received the two Narva LED map lights that I ordered to replace my Patrol's factory fitted map lights. While a little expensive, these units feature a 1 Watt Cree LED, similar to those used in LED lightbars for extra brightness.

I chose to mount the lights in the centre of the console as opposed to the traditional place of just behind the sunglass holder for two reasons; The first is that the lights would obstruct the line of sight of the driver & passenger looking at the switch panel, and the second is that mounting the lights in the console's centre have an advantage as to allow the lights to be directed forward (They swivel and tilt) for use as map/reading lights as well as backwards to illuminate the rear of the cabin.

Until I receive the high capacity fans for the computer, the project is in hiatus. I will post up my progress as soon as I make it. Until then, bye and thanks for reading.