Where should windows be placed for passive solar heating?
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如何计算被动式太阳能采暖的窗户高度和位置?
Daniel Gardener
Sept. 12, 2019Last updated: Aug. 4, 2020
我在搜索中看不到答案——如果这已经被覆盖了，我道歉。
If I know that at the winter solstice the sun will be at an elevation of 20 degrees, my south facing (northern hemisphere) glazing is 4 metres high (bottom to top of windows) - then what is furthest point the sun will reach to into the home ? What is the calculation here? Memories of high school maths isn't helping me here.
This is to help with the placement of thermal mass walls. I.e if the sun only reaches 2 metres into the living space, then is there a point in placing thermal mass 5 metres into the living space ?
Thank you
What you need to find is thehypothenuse, so if you can’t find your high school trigonometry text book you can use anonline calculator, but this does require inputting the correct angles and distances. 'Garbage in, garbage out' as they, the answer is only as accurate as the figures you punch in. That would require determining theangle of the sunbased on yourlatitude, and knowing the exactoverhangyou want on your roof, and theheight of the windows. Before your head explodes though, check out this page. I promise it will be more fun to read than a page on trigonometry -
The basic Concept Passive Solar Home Design
If it's mid-September and you are calculating this now, does that mean you are still in the design phase or have you started building? If so, and if you’re not a mathemagenius, AND you can wait until December 21st, then you could just do it on site by hand and not risk having made any mistakes in calculation.
First, to orient you home properly, go to your site any day at noon and pin the exact location by driving a stake in the ground (straight would be good), and the shadow will tell you the exact orientation you’d want for your south facing wall to maximise your solar gain. That way you won’t get confused by ‘true north’ and ‘magnetic north’.
然后，在12月21日中午，你可以把3个2x4钉在一起，形成一个水平的板，你可以把它举到悬着的高度，看看影子落在哪里，你就会得到答案。
It’s a great question and I really wish we could help more, but in order to solve it not just for winter heat gain but for summer shading, you do need to have a whole bunch of variables on hand like window size, where it will be in the wall and the height and length of your overhang, and the exact angle of the sun.
And while you may pick up a few more BTUs here and there due to the exact location of thermal mass in relation to the windows, keep in mind that once the energy is in, it’s in. If you have a bright and reflective floor, it will reflect the light (and heat) towards other surfaces than may then absorb additional heat.
我们能提供给你的最好的建议是，不要在你的脑袋上挖一个洞，试图把它弄到厘米，因为有太多的变量，让你有价值地利用你的时间，除非你真的喜欢这样做。This page onhow to design for passive solar heat gainmay help, best of luck!