Browse Forums Windows & Doors 1 May 20, 2012 1:37 am I have a solar passive house design and I'm a few weeks away from starting the build. I have a question about some window choices I've made. The window brand is Vantage Magnum. The windows in question face north-northeast and the prevailing winds are north-west. The build is in Canberra. The architect has recommended awning windows throughout. However around the deck I've asked for double-hung windows because I don't want the rugrats bumping their heads into opened sashes. Even with the corner protectors they might do themselves a nasty injury on the aluminium frames. The architect has explained some of the tradeoffs. The awning windows have a much lower air-infiltration (0.12 vs 4.75) so the double-hung windows will admit cold winter drafts. The architect also explained that summer ventilation isn't a problem with awnings because the airflow is due to pressure differences, not the shape of the windows. I can also see that stylistically the awning windows look pretty slick. I pushed (very lightly) for double-hung windows in a few locations on the basis of not bumping into the sashes and the architect complied without argument, but he rarely argues. I'm wondering how much this will affect the solar passiveness. The house has no active cooling and only slab heating. I will ask the architect but I'd like advice from these forums as well. It's always good to hear more than one opinion. There are 6 windows I've asked to change from awning into double-hung. The remaining 30+ windows will stay as awnings. The 6 windows in question are in high traffic areas where the awnings would open across walkways or directly onto the deck. Will awning windows really be that much of a hazard? Will the change in air infiltration matter all that much? I have no qualitative understanding of what "4.75" means in terms of drafts. Is that going to be cold and uncomfortable? Or is that only a few extra dollars per year on heating? Re: double-hung vs awning; solar-passive vs practicality 2May 20, 2012 8:17 am Hi Nhand42, Do you have any information about which direction the summer breezes come from in Canberra? This might help you decide whether the windows you are talking about are that crucial to summer cooling. I don't know how much difference the drafts would make to your winter heating bills. Are these Shugg windows we are talking about or the traditional double hung? You have 30plus windows? That in itself seems an awful lot of windows to me and a lot of heat loss but then we have a pretty small house compared to most people here. Hope somebody else here can help with the technicalities. Re: double-hung vs awning; solar-passive vs practicality 3Jul 01, 2012 11:00 pm Hi Nhand42 A passive house has basically no opening windows, and to follow the european concept should be at least double glazed, and fixed. your architect should have advised you of this. If the house is passively heated and cooled, by heat and cooling air exchange, you should be able to utilise the north facing aspects. Artificial air conditioning can be minimised or abandoned - especially if you build using something like sips panels, which are the most energy efficient building system available - proven thoughout europe and the us. cheers Jeff Re: double-hung vs awning; solar-passive vs practicality 4Jul 02, 2012 1:42 am winentucker A passive house has basically no opening windows Say what? nhand42, how many degrees off north do the windows face? I think if you're talking literally NNE or 22 degrees then you're outside the ideal orientation anyhow. I reckon your safety concerns are a valid reason to compromise, if infact it is a compromise. I've heard different things about the pros and cons of different style windows but awning windows have usually been described as worst for cooling. Another thing that's started to be talked about is modern houses being so well sealed they're unhealthy especially if steps haven't been taken to reduce VOC's, etc. So the advantages and disadvantages get quite complicated. Double glazed anything is going to be better than single glazed so I wouldn't lose sleep over a draft that probably only a scientist could measure, go with what's safest around the deck. You've got plenty of other opportunities to make efficient choices all round the house, summer shading, eaves and pergolas, deciduous trees, insulation around external doors or better yet airlocks, all types of things to consider. Around the deck where there's lots of activity best to go with safety/practicality IMO. Btw what windows do you have on the opposite side, did you factor in late afternoon sun in summer on that side (that came as a surprise to us and we're quite close to north)? Re: double-hung vs awning; solar-passive vs practicality 5Jul 02, 2012 6:33 am JazzyJess nhand42, how many degrees off north do the windows face? I think if you're talking literally NNE or 22 degrees then you're outside the ideal orientation anyhow. I reckon your safety concerns are a valid reason to compromise, if infact it is a compromise. I've heard different things about the pros and cons of different style windows but awning windows have usually been described as worst for cooling. Another thing that's started to be talked about is modern houses being so well sealed they're unhealthy especially if steps haven't been taken to reduce VOC's, etc. So the advantages and disadvantages get quite complicated. Double glazed anything is going to be better than single glazed so I wouldn't lose sleep over a draft that probably only a scientist could measure, go with what's safest around the deck. You've got plenty of other opportunities to make efficient choices all round the house, summer shading, eaves and pergolas, deciduous trees, insulation around external doors or better yet airlocks, all types of things to consider. Around the deck where there's lots of activity best to go with safety/practicality IMO. Btw what windows do you have on the opposite side, did you factor in late afternoon sun in summer on that side (that came as a surprise to us and we're quite close to north)? Thanks for the thoughtful reply. Yes, the windows are precisely NNE and your point about it being a compromise to improve safety is a good one to me. I'm willing to make that compromise. As you say, it's a minor variation that won't matter too much. There are other things to worry about. Thanks again. Re: double-hung vs awning; solar-passive vs practicality 6Jul 02, 2012 9:11 pm There need be no compromise with tight-sealed homes - you need to ventilate with a heat-recovery system! We're aiming for exactly that with our new home. We plan to use a system likes those made by Venmar, Zehnder, Air-Change or Lossnay (Mitsubishi) that are roughly 80-90% efficient when forcing out stale air and bringing in fresh from outside! The air conditioning contractor I met with advised me to get a regular ducted heating quote for heat pump and then they can take the design, add their ERV in-line with the outdoor unit. Win/Win! 0 4934 4 14128 I looked into it a few years ago and my conclusion was to just build a carport that will support panels and get a system installed separately. The company I looked at had… 1 6457 |