Browse Forums Windows & Doors Re: U-value vs SHGC & double glazing 21Nov 23, 2008 5:14 pm "Now, supposing a house to have a southern aspect, sunshine during winter will steal in under the verandah, but in summer, when the sun traverses a path right over our heads, the roof will afford an agreeable shade, will it not?" -- Socrates, ca. 400 BC Re: U-value vs SHGC & double glazing 25Nov 24, 2008 8:54 am "Now, supposing a house to have a southern aspect, sunshine during winter will steal in under the verandah, but in summer, when the sun traverses a path right over our heads, the roof will afford an agreeable shade, will it not?" -- Socrates, ca. 400 BC Re: U-value vs SHGC & double glazing 27Nov 24, 2008 10:08 am "Now, supposing a house to have a southern aspect, sunshine during winter will steal in under the verandah, but in summer, when the sun traverses a path right over our heads, the roof will afford an agreeable shade, will it not?" -- Socrates, ca. 400 BC Re: U-value vs SHGC & double glazing 38Nov 24, 2008 5:59 pm windowexpert Regardless of all theories. A poor frame and single glazing is a cold surface which causes discomfort. It feels like sitting beside an open frigde and even with heavy drapes the cold sneaks up on you Everyone around here who has changed to double glazed PVCu or timber windows from single glazed wood or aluminium (without having changed anything else in the house!!) is going on about how much warmer the house is Theory is one thing, the real physical experience is the other True if you were to snuggle up close to an uncovered window on a winter night or actually leant against the pane Most people don't this. If you stay within reasonable limits of the external envelope the ambient air temperature is nowhere like that experienced near the window itself. The effect is lessened even more with a reasonably fitted window covering. Moreover, there is enough radiant heat from the interior structure to provide adequate comfort. Part of the discomfort near a sunless window is that there is no significant radiant heat approaching from that angle. That is negated the further away you move from it. Re: U-value vs SHGC & double glazing 39Nov 24, 2008 6:32 pm dymonite69 , it is impossible to achieve a zero energy dwelling by passive means alone. You will always need some kind of additional heating input. Your body, with its metabolism, provides a heat input, as does any electrical or gas appliance you use. I seem to remember reading about houses that can stay warm enough merely with those heat sources. I used to argue with my wife about that when we were stuck in a rental with only electric heating. She would go round turning off unused lights and so-on to "save energy" and would not listen when I told her it would merely cause her to need to turn the heater up to use an extra amount of power exactly equal the amount no longer being burned by the lights . Still, those amounts are miniscule compared to the total amount used on heating. "Now, supposing a house to have a southern aspect, sunshine during winter will steal in under the verandah, but in summer, when the sun traverses a path right over our heads, the roof will afford an agreeable shade, will it not?" -- Socrates, ca. 400 BC Re: U-value vs SHGC & double glazing 40Nov 24, 2008 6:45 pm russell dymonite69 , it is impossible to achieve a zero energy dwelling by passive means alone. You will always need some kind of additional heating input. Your body, with its metabolism, provides a heat input, as does any electrical or gas appliance you use. I seem to remember reading about houses that can stay warm enough merely with those heat sources. Incidental heat from other domestic appliances can be significant but I am not aware that this can provide the only source of heating energy in extreme climates. Again it is a matter of proportions. Just turning on a stove top or oven might be quite adequate for a mild climate. The opposite would be true in densely populated structures such as office buildings. Human activity, lighting and computer stations will require systems to actively prevent the building from overheating. This is one of the reasons I decided to go overseas for my double glazed windows. As the builder indicated, he's worked on many upmarket builds, these were the most well… 13 19841 As a tradesmen get a private inspector although I don't think there worth it in their profession themselves the reminder they serve to the tradesmen doing the work is… 3 27756 |