Hi, I hope it is ok to post my similar query. I too have an HP machine with that fan. I am thinking of buying http://www.amazon.co.uk/gp/product/B003KWSI68/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=A3P5ROKL5A1OLE
however my HP Compaq dc5800 Model # ( KK375ET has a plastic tunnel thing between the CPU cooler and the front grill thing (see black plastic tunnel): http://www.ctsestore.com/sites/default/files/styles/pic_wm/public/HP_Campaq_DC5800_Tower_04.jpg
is there any way to know if the fan inside this (it clips into the tunnel) is interchangeable with another fan?