Just wanted to add to this as I'm running the HGG Merlin Fork on my AC87U right now and enjoying the options to increase transmission power but didn't want to push it too far until I got some cooling sorted out.
Therefore (and after reading this thread) I went and grabbed this:
http://www.ebay.co.uk/itm/281067042733?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Considering it was so cheap I expected rubbish and figured the fans would be crap and at least I can use the perspex plate to mount some good quiet fans on that I can get elsewhere.
It arrived today and I thought I'd give it a try as is and have so far been pleasantly surprised.
The AC87U fits on it perfectly and the usb power cable I just plugged straight into the USB2 socket at the bak of the AC87U and USB plug itself has a male and a female end, so you can still plug in something like a printer.
As for the temps I'm running said firmware with both the 2.4 GHz and the 5GHz running at 75% which really strengthens signal and coverage for me and when I first plugged this cooler in my temps were as below
but within half an hour they were down to
2.4 GHz: 45°C -
5 GHz: 56°C -
CPU: 77°C
which is quite a big deal for something I was going to just buy for parts!
Anyway, I want to try this firmware at 100% on both and see how this handles (remember that o% on this fork is greater power than 100% on the regular Merlin) but was thinking on a slight mod first.
Someone on this thread raised concern re all that cold air (and dust) being forced in with no place to escape, so I was considering reversing one of the fans (maybe the middle one) to pull instead of push, so the 2 at the side are blowing in cold air while the centre one is sucking out the hot.
Given there are a lot of ventilation notches all over the bottom of the AC87U and the cooler's fans are attached with screws it could be pretty easy and worth trying.
Anyone got any thoughts on this? Would it make a difference which fan I changed in relation to the positioning of (for example) the cpu?
So a question and a cool result from a cheap ebay purchase!