We've been putting the Globus bioethanol fire from Imaginfires through its paces over the past few weeks...when it's been pretty chilly of an evening. And my partner, teenage sons and myself have become rather fond of it.
Perhaps the first thing to note is that contrary to expectation, the fire does heat up the sitting room when on 'full blast' so to speak (ie the aperture for flames is opened to its maximum).
You hear that they're these fires are really just for decoration and the heat they emit is pretty feeble, but we've found that if you close the sitting room door and put Globus to work, the room heats up nicely. ...Whether it would make a noticeable difference on a below zero day in the depths of an icy January (we didn't have any such days in January this year...), with no central heating on, I can't comment on; but on a fairly cool evening when the heating's gone off, the Globus does warm things up.