Browse Forums Heating, Cooling & Insulation 1 Jan 30, 2010 4:31 pm Is it better to have bare north facing windows in winter and let in the light and heat or to have low-E film installed and try to keep the heat from escaping even though Low-e will block some light and heat from coming in. The specific coating I'm thinking about is AG-25 low-e from solar gard. Claimed to have 77% heat rejection and keeps heat in during winter months. If it helps, I have a north facing living area with external awnings for summer and cellular blinds inside. Gravity. Its the law. At lock-up stage(lock-up stage) https://forum.homeone.com.au/viewtopic.php?f=31&t=25438 Re: Low E or passive solar 2Jan 30, 2010 4:45 pm Low-e doesn't address the significant convective losses through the window and it will compromise warming winter sun. If you get the north shading right with normal glass then you shouldn't have to worry too much about overheating during summer. If you are also using window coverings you will already do something to reducing radiant loss anyway. From a cost effectiveness point of view, you can probably achieve comfort conditions with a standard passive solar design with normal windows, a properly designed eave and insulating curtains or blinds. Low-e and double glazing has more value if you are going to leave the windows uncovered. Off course if you want to achieve maximal thermal performance than DG +/- low-E + window coverings give the best outcome; but it will take quite a while to recoup the additional investment for special glazing. Re: Low E or passive solar 3Feb 01, 2010 6:59 pm Good point Dymonite. If the windows are in shade it only stops 77% of what's left, likewise for internal heat losses and cellular blinds. Thanks. Gravity. Its the law. At lock-up stage(lock-up stage) https://forum.homeone.com.au/viewtopic.php?f=31&t=25438 0 4982 4 6201 If you can calculate the reasonable charged head from let's say 100mm below the gutter to the top of where the vertical riser's horizontal discharge pipe will be, that… 11 17530 |