Re: Figuring the right frame angle on the roof
- View SourceHey Zawy,
You were right on that roof angle, it was to flat and I was
Now that the weather's cleared and I can get out there.
I measured/counted the siding rows to the peak and house
width and came up with 80" by 216" (from center of house)
that makes it 20.32 degrees.
So if that's the case I would only have to raise up the
top end of the 4' panel about 6 degrees or about 4.5" to
Did I get that right?
--- In SimplySolar@yahoogroups.com, "zawy" <zawy@...> wrote:
> At your 44 degree latitude (the only number that matters), you can set it anywhere from 10 to 40 degrees (where zero degrees is mounted on a wall) and the total sunlight collected between 9 am and 3 pm from November 1 to March 1 will be 510 kWh per m^2, if every day were sunny. 26 degrees is the ideal angle, giving about 5% more than 10 and 40 degrees. Taking sky reflection into account, and if you also need heat in April, 30 degrees might be the ideal angle. This assumes you want it for winter heat, it's facing directly south, and there no trees are in the way from 9 am to 3 pm.
> 2" rise for 12" run in the roof is 9.5 degrees from horizontal, 80.5 degrees from wall mount (that seems too flat for 44 latitude). Going up from 80.5 degrees to 30 degrees means 50.5 tilt up from the roof. A support that is perpendicular to the roof that meets the top of the collector will be 0.77 times the height of the collector. That is, a 4 foot wide collector will be 3.1 foot from the top of the collector to the closest point on the roof (perpendicular).
> A wall mount on the south wall will be 15% less efficient than this ideal roof mount, provided it does not block any windows and is not under shadows.
> --- In SimplySolar@yahoogroups.com, "Inventor" <welfab@> wrote:
> > Hey Guys,
> > I've done a dozen searches and I can't find anything
> > that clearly tells me how to figure out the right
> > frame angle for my location.
> > One website form shows:
> > Declination: 23.0045
> > Solar zenith angle: 66.9973
> > Lat: 43.99° Long: -89.81°
> > Now my roof is the standard 2" in 12" pitch.
> > So how do I figure the angle of the support
> > frame for the panel.
> > Thanks,
> > Grandpa Bill