Recently, I put together a second system for the study and the Electrocompaniet PI-2 integrated tends to run on the hot side and the recent heatwave here in Johannesburg hasn't helped either. To keep the amp from getting too hot, I've been using a floor fan but this is a noisy SOB.
Checked out AC-powered axial-flow fans but all I could find were "screamers" - more focused on pushing high flow rates than on keeping noise levels down to somewhere acceptable in an audio rack.
Decided to opt for PC chassis fans (12v DC) and found one that met the requirements - Cooler Master 140mm Silent Fan which delivers 60cfm at 1,000 rpm with a noise level of 16dBA. Being a firm believer in overkill, ordered two of these fans and then started to scratch the old noggin around how to mount them. Sticking with the PC platform, did some digging into chassis accessories available and found that Lian Li offer an after-market 2 x 140mm fan top panel for their D8000 chassis and ordered one. (This panel - made from black anodised aluminium - ships with all holes CNC cut and includes the exterior mesh grilles and interior finger guards plus all the necessary mounting screws/bolts). Fans mounted on panel to provide extractor airflow (i.e. from the "interior" to the "exterior").
Next was how to provide an adequate supply of 12v DC to run these two fans (which each draw just under 0.1 amps at 12v DC). Opted for a 12v 1.5 amp SMPS-based wall-wart.
Then came the switch box which needed to accept the 3.5mm 12v DC barrel plug for input and provide dual switched outputs - one per fan. Decided to standardise on the 3.5mm 12v DC barrel sockets - one for the DC input from the PSU and two for switched outputs to the fans. Found a decent black plastic box with 5mm walls that was also just right size. The diagram below shows both the layout and the wiring for this wee box:
Knocked together the switch box (and tested thoroughly with a multi-meter) and mounted the fans onto the fan panel. Next followed a bench test and everything worked, so installed both the fan panel and the switch box (see below):
"Interior" View:
"Exterior" View:
With both fans running at 1,000 rpm, there is no discernible (or audible) evidence that they're actually running and the extraction works well - the amp runs just above ambient temperature.
All in all, a happy outcome - it works well, airflow adequate to keep amp cool, noise level virtually zero and the fan panel even looks reasonably professional (which is more than I can say for the 30+ year old mobile stand that is performing stop-gap duties while its replacement is under construction - took a break to give an old knee time to recover from recent abuse). Even SWMBO is quiet...
Dave
Checked out AC-powered axial-flow fans but all I could find were "screamers" - more focused on pushing high flow rates than on keeping noise levels down to somewhere acceptable in an audio rack.
Decided to opt for PC chassis fans (12v DC) and found one that met the requirements - Cooler Master 140mm Silent Fan which delivers 60cfm at 1,000 rpm with a noise level of 16dBA. Being a firm believer in overkill, ordered two of these fans and then started to scratch the old noggin around how to mount them. Sticking with the PC platform, did some digging into chassis accessories available and found that Lian Li offer an after-market 2 x 140mm fan top panel for their D8000 chassis and ordered one. (This panel - made from black anodised aluminium - ships with all holes CNC cut and includes the exterior mesh grilles and interior finger guards plus all the necessary mounting screws/bolts). Fans mounted on panel to provide extractor airflow (i.e. from the "interior" to the "exterior").
Next was how to provide an adequate supply of 12v DC to run these two fans (which each draw just under 0.1 amps at 12v DC). Opted for a 12v 1.5 amp SMPS-based wall-wart.
Then came the switch box which needed to accept the 3.5mm 12v DC barrel plug for input and provide dual switched outputs - one per fan. Decided to standardise on the 3.5mm 12v DC barrel sockets - one for the DC input from the PSU and two for switched outputs to the fans. Found a decent black plastic box with 5mm walls that was also just right size. The diagram below shows both the layout and the wiring for this wee box:
Knocked together the switch box (and tested thoroughly with a multi-meter) and mounted the fans onto the fan panel. Next followed a bench test and everything worked, so installed both the fan panel and the switch box (see below):
"Interior" View:
"Exterior" View:
With both fans running at 1,000 rpm, there is no discernible (or audible) evidence that they're actually running and the extraction works well - the amp runs just above ambient temperature.
All in all, a happy outcome - it works well, airflow adequate to keep amp cool, noise level virtually zero and the fan panel even looks reasonably professional (which is more than I can say for the 30+ year old mobile stand that is performing stop-gap duties while its replacement is under construction - took a break to give an old knee time to recover from recent abuse). Even SWMBO is quiet...
Dave
