Completely new to this forum but looking for some advice. My wife and I are hoping to start construction on house in about 1 month. We have a passive solar design and are going with Andersen 400 series casement windows throughout. We wanted to potentially get passive sun style windows from Andersen 400 series on the south side. The specs on those windows are (U factor)-.29, SHGC-.52. The rest of our house will have standard Andersen casements with (U factor) and SHGC both below .3. We live in southeastern PA(Landenberg) and according to the chart on Andersens website we are just out of range for what they would recommend for passive sun windows. I have two questions. Do you all think it's worth it to get passive sun windows on south side to allow for more warmth in winter time, and also based on drawings, does our roof go out far enough to block sunlight in summer time or should we see if it can be extended slightly? Thanks for all of your help!
Are you out of range to the south or to the north, according to the chart? I can say that in south central New York, the heat mirror windows on the south face make a tremendous difference. (Heat mirror is "triple-glazed" with the middle pane being mylar coated with a heat-reflecting material.) On a cold sunny winter day, the house gets to a comfortable temperature without the heat coming on at all. I think the SHGC is between .7 and .8+.
For overhangs, I don't see a drawing, but the 20" or so overhangs above my windows work excellently for excluding sun in the summer and allowing it in winter. I'm a little bit farther north than you.
I don't know anything about modern fancy solar windows, but I have lived in passively solar heated houses in a cold climate for over 20 years, and I can say that using thick curtains for winter nights makes a huge difference. We have just single or home-made crappy double glass, not special coatings, nothing. Even if the windows don't have adequate insulating value on their own, you can put up thick curtains made of blanket cloth for the winter, and diligently open and close them every morning and evening during the coldest season. Then in late winter when they seem less necessary, take them down, wash them and store them. I believe this will make your solar windows much more effective.
PS You can add your location in your profile so that it shows on every one of your posts, and it will make it easier for people to respond to your future posts or questions.
Works at a residential alternative high school in the Himalayas SECMOL.org . "Back home" is Cape Cod, E Coast USA.
An 18" overhang might be enough for windows on the second floor but wouldn't help on the first floor. You could consider add a overhang above them too. It would make it easier to to open what looks like a sliding door in snow or freezing rain anyway. Passive solar great. Something for nothing since you need windows anyway. Fred
Yeah Fred the plan is to put a wrap around porch in between first and second floor which will create that overhang. It just isn't in the budget yet. Our main living space is on what looks like second floor on that picture.
Just saw the newer posts to this thread... I would note that any porch on the second floor level unless it is less than four feet wide would block all solar gain on the first floor windows. You might get useful exposure around the solstice, but that would be about it, depending on the details of your layout.