If you look close at the 4U rackmount case it has 2 temperature displays on the front, one is on the HD's and one is the room temp, the sensors are on leads so they can be positioned, so I know there is a heat problem from looking at them.

What I want is a solution that will allow me to monitor the temps on a webpage, and automatically activate some form of cooling system when needed, without me having to go open the door for a bit

It's not major problem at the moment, but if I do move to a server system that has no active cooling at all it could become one I think. For now I guess I will just keep on opening the door every few days and letting the heat escape into the house.

Cheers

Cris.