Towards the bottom of this thread: http://forums.moneysavingexpert.com/showthread.php?t=923211
is a discussion about how failure of the seal around the edge of a DG pane affects its ability to perform thermally. I've currently got tenants who are complaining that windows are leaking water in and it's because the DG seal has failed, yet I know this isn't technically sensible as a DG unit misting up says nothing about the watertightness of the frame. I'm more convinced that the water they find on the windows at the moment, is condensation because they don't run the heating often. They say they've made all the necessary lifestyle adjustments, and the water is always there whether they open the windows or not, so it got me wondering by how much a DG unit underperforms if it's no longer gas tight. My personal feeling is "not much" because the insulation comes from trapping a layer of air between two panes so that it cannot convect or conduct. Sure, wetter air in there might have a slight performance impact but I think the main reason we go to efforts to keep the air in a DG unit dry is so we can still see out the window, rather than for thermal performance
I need to go and have a look at the frames to check that they aren't actually leaking/drains are clear, and if the panes are misted up really badly then I'll consider replacing them on aesthetics. I just get the feeling that the tenants are expecting it to be a magic bullet that will solve the problem when I'm more inclined to think that it's a lifestyle+current climate combination
is a discussion about how failure of the seal around the edge of a DG pane affects its ability to perform thermally. I've currently got tenants who are complaining that windows are leaking water in and it's because the DG seal has failed, yet I know this isn't technically sensible as a DG unit misting up says nothing about the watertightness of the frame. I'm more convinced that the water they find on the windows at the moment, is condensation because they don't run the heating often. They say they've made all the necessary lifestyle adjustments, and the water is always there whether they open the windows or not, so it got me wondering by how much a DG unit underperforms if it's no longer gas tight. My personal feeling is "not much" because the insulation comes from trapping a layer of air between two panes so that it cannot convect or conduct. Sure, wetter air in there might have a slight performance impact but I think the main reason we go to efforts to keep the air in a DG unit dry is so we can still see out the window, rather than for thermal performance
I need to go and have a look at the frames to check that they aren't actually leaking/drains are clear, and if the panes are misted up really badly then I'll consider replacing them on aesthetics. I just get the feeling that the tenants are expecting it to be a magic bullet that will solve the problem when I'm more inclined to think that it's a lifestyle+current climate combination