Our house is Listed, so we can't change five of the windows. They mist up in winter - have to be wiped every day - and obviously also allow the heat to escape. The opening lights are not very draught-proof, either.
Upstairs
are three three-light casements, the centre light is hinged. Each of the three windows is about 1350 x 1000 high between reveals. One room has another (double glazed!) window on the opposite wall, so may be completely sealed; the other two need to have the opening light usable as a fire escape.
Downstairs
are two sash windows, each about 1380 x 1550 high between timber reveals. Both may be sealed.
What I am thinking of, for the three windows I can seal, is to just fix a sheet of clear acrylic, with draught-proofing strip round the edge of the face, and held in place by a small bead panel-pinned to the timber reveal, then painted.
Or maybe even, instead of that bead, a 10 x 20 strip all round, then another sheet of acrylic, THEN the bead, so it's triple glazed with a 20mm gap.
For the other two, that have to have the opening light usable, I would do the same, but add a vertical mullion on each side of the opening light, and then make a hinged frame for the acrylic sheet for the opening light.
Anyway... my question is - whaddya think ? Has anyone tried this ?
*I* am not too bothered about the look of the thing - the edges will be behind the curtains anyway - but Senior Management is not very happy with the idea.
AND.. crucially - what thickness of acrylic should I use ? The price varies with thickness, so 4mm would be twice the price of 2mm.
Or should I use glass ? It would have to be toughened, as the sills are quite low. Or should I use sealed double-glazed units - MUCH more expensive ? Should I really install frames ?
And finally
what's the best way to set about fixing the sheet so that the trapped air is as dry as possible, to prevent misting on the now unreachable glass ?
Upstairs
are three three-light casements, the centre light is hinged. Each of the three windows is about 1350 x 1000 high between reveals. One room has another (double glazed!) window on the opposite wall, so may be completely sealed; the other two need to have the opening light usable as a fire escape.
Downstairs
are two sash windows, each about 1380 x 1550 high between timber reveals. Both may be sealed.
What I am thinking of, for the three windows I can seal, is to just fix a sheet of clear acrylic, with draught-proofing strip round the edge of the face, and held in place by a small bead panel-pinned to the timber reveal, then painted.
Or maybe even, instead of that bead, a 10 x 20 strip all round, then another sheet of acrylic, THEN the bead, so it's triple glazed with a 20mm gap.
For the other two, that have to have the opening light usable, I would do the same, but add a vertical mullion on each side of the opening light, and then make a hinged frame for the acrylic sheet for the opening light.
Anyway... my question is - whaddya think ? Has anyone tried this ?
*I* am not too bothered about the look of the thing - the edges will be behind the curtains anyway - but Senior Management is not very happy with the idea.
AND.. crucially - what thickness of acrylic should I use ? The price varies with thickness, so 4mm would be twice the price of 2mm.
Or should I use glass ? It would have to be toughened, as the sills are quite low. Or should I use sealed double-glazed units - MUCH more expensive ? Should I really install frames ?
And finally
what's the best way to set about fixing the sheet so that the trapped air is as dry as possible, to prevent misting on the now unreachable glass ?