Solar Heat Gain: Marvin vs. Andersen Windows
I’m in Climate Zone 6A (Maine), building 734 sq ft with south-facing clerestory windows.
I’m down to Andersen A-Series or Marvin Elevate for the building, neither of which has high SHGC, and wondering about special glazing on just the south-facing clerestory windows for passive heating (I want it toasty!).
Any thoughts on what glazing to request for Andersen A-Series or Marvin Elevate for south-facing clerestory windows? Or what SHGC to shoot for?
The “standard” options so far are:
Marvin Elevate double-pane: SHGC 0.30; U-factor 0.27
Andersen A-Series double-pane: SHGC 0.26; U-factor 0.27
It looks like “standard” Andersen A-Series are Low E-4, whereas Marvin is Low E-2, and both have alternative glazing (for $). Is Low E-1 enough?
I understand that Low E-4 can create the coolest interior surface which could increase air circulation (don’t want). Moreover I want to take advantage of winter sun to heat the space. I’m okay with double-pane for the clerestory windows because people won’t be physically close to them…I prioritized triple-pane in window seats and a kitchen window where human bodies will be physically close.
A couple of other notes:
– The clerestory windows are 3×3 feet each and 3 of 5 clerestory will be awnings to let out summer heat.
– Heating is heat pump in each space + backup wood stove for outages + “booster” heat because this is a yoga space that I want to keep toasty.
Thank you! All advice welcome!
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