Placement of fans on top of hot Onkyo AVR

Just picked up a relatively lightly used Onkyo HT-RC 160 AV receiver that I've placed in my office for (mostly) movies and surround-sound playback. The sucker runs crazy hot, not helped by a three-inch clearance between the top of the unit and a glass shelf above it. Anyway in a fit of brilliance I went to Frys and grabbed two super-quiet computer fans (shown, about 5" x 5" apiece) that I connected to an AC adaptor for power. They work like a charm but here's the question, dumb as it it may be:

Should I place one in a downward-firing position and the other in an upward-firing position above the "hottest" areas on the grills, or it is better to have both firing in the same direction? The upward/downward combo definitely makes a big difference but if there are any dangers/concerns you see in this approach I'd love to get some feedback. Thanks, nerds!

 

Heat rises, and that's how it should already be moving thru the unit, though slower than you like. I'd have both on top, above hottest areas, pulling air upwards

 

Have you opened it up and given it a really good cleaning as well?

 

After I had a previous AVR fail because of (I believe) overheating, I added a computer fan blowing upwards above the heatsinks of its replacement. So far so good.

My older Nakamichi receiver also runs hotter than I'd like, so I did the same thing with that, too. Cheap insurance.

 

I wouldn't mess with the airflow inside the unit just in case. Usually they build the units so they can get rid of the heat in a certain way and interfering with that could make it worse. Also, blowing air in might also increase the dust going into the unit.

 

Yup!

 

Good point. Blowing upwards it is! (fans are on top of the unit, not inside btw).

 

I use these for that purpose. Blows air out of the cabinet, instead of up into the shelf, and is USB powered by the AVR itself so turns on and off with it.

https://smile.amazon.com/gp/product/B012CL2V3I/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

Protip: positioned as close to the HDMI card in the unit as possible.

A larger slow fan, such as a 200mm one at 600rpm, can be nearly silent while still moving air. Any fan is better than the wishful thinking that receivers are designed with, so you don't need to add much.

 

In several reviews of the Onkyo 905 AVR they warned not to put it anywhere there is little space around they unit. It runs damn hot even in the wide open.

 

With only 3 inches of clearance no wonder it runs hot. You want fans that blows air out of the cabinet like JackG suggested, I have one similar to the one he posted on top of my Onkyo AVR it runs cool to the touch, I do however have more than 3 inches of clearance.

 

Exactly where I put the first one!

Yeah it sure does. Look, if it croaks even with the fans I'll just replace it---got a great deal on it from Craigslist and so far it's performed flawlessly. It's my first HDMI-capable AVR (replaced an 18-year-old Denon 3300) and I love not having 67 RCA cables going into it from my TV, Oppo, BD and CD players

The two fans I've placed atop my Onkyo are doing a yeoman's job so far. Thanks to everyone for the suggestions and help!

 

Faced with similar issues, I bought 2 of these. Works great!

https://www.amazon.com/AC-Infinity-...1531410052&sr=8-1&keywords=ac+infinity+aircom

FYI - You can purchase them configured to blow air to front, back or up.

 

I considered something like that but my solution ended up costing around $30 The only downside is I have to remember to plug in the AC adaptor when I need the fans to run and unplug them when I'm done.

 

Maybe try this then? https://www.amazon.com/AC-Infinity-CONTROLLER-Thermostat-Controller/dp/B00NG9TSG4

 

Cool (pun intended). Certainly sexier than what I came up with!

 

I hate to hear new recent Onkyo receivers still run hot. I have a 10-year old TX-NR805(part of the brand's notorious "05" AVR series which had the failed HDMI & front display failures). I use a battery-powered personal fan from Wal-Mart atop of the 805 to keep it cool, lifting heat away from the AVR. I believe that have extended the 805's longevity.

 

IF that's not enough, you can study this video

 

I still use my Onkyo tx nr 808. Similar to 805, the model has high incidents of hdmi board failure. When it was inside the entertainment center, it had little clearance and using 2 fans apparently helped greatly in avoiding the hdmi failure. Right now it is out of the cabinet and still going strong.

 

I bought one of these, USB powered, quieter than a flea fart on H speed. I run it on my NAD integrated that sits in a cabinet with 3-4" of clearance, pulls out more than enough air on L speed. It has rubber feet on both sides so does not scratch anything and can be used upright or flat.
https://www.amazon.com/AC-Infinity-..._rd_t=40701&psc=1&refRID=TPYDG3BD28F981TMPVGK