9 o'clock and still showing only 1.5oC.
This year's project to double-glaze all 12 large sliding sash windows in this place has proved its worth. A comfortable 17.7oC in here, yet this time last year with a similar outside temperature I'd have had to have had at least one bar of a 1kW halogen heater on under this desk to make it even possible to sit here and still have the use of my fingers.
Some condensation along the bottom edge of the units, but as it was necessary to fit 16mm low-e gas-filled 2g (a shorthand for double-glazing, and similarly 3g is easier to state than triple glazing), I was expecting it and anyway it's a damn sight better than having the entire window opaque with condensation with water running down onto the window cills, as it is, the stuff that's there will evaporate as the outside temperature lifts and units warm, helped of course by the escape of the heat that the stated u-value of 1.9 allows. That's a real bugger.
That last bit is the problem with sliding sashes in old buildings, especially where the window frames are located behind the outer skin of brick, 'rebated' in to reduce the amount of exposed frame (see my blog on sash window construction). Frames fitted into older buildings where that rebate isn't present (either because they pre-date the regulation that demanded it, or where the requirement was ignored because the reason given for it was not considered an issue) do offer the chance to fit 3g sliding sashes because the frame can then be made to accommodate the significantly increased depth needed. Although methinks your CO might be of a different opinion, because if your building does pre-date those regulations then you'll be Listed (you might be anyway).
Casement windows, of course, don't have these problems. Let's hear it for casement windows, folks.
Edited by joiner, 14 October 2012 - 08:18 AM.