New darkroom shed

Is this the heater? What wattage and how well did it keep the shed warm enough in the quite severe winter we have just had?Thanks

No, this is the inward ventilator fan. I bought fans from Radio Spares and made my own lightight cowls from plywood. The design challenged my (increasingly) grey cells, which is why I have also posted a picture of the inside of the cowl, which sticks on using a couple of magnetic cupboard latches. The heater is an oil-filled electric type (floor-standing). The inner door has been off until two weeks ago, but the heater was plenty to keep this little room warm during the winter. There is 5 cm of foil-covered foam insulation, plus one layer of that silver bubble-wrap insulation, which is supposed to be the equivalent again. I insulated walls and roof, then covered the whole with roofing membrane, before battens and ship-lap boards. So it is snug.