<html><body><div style="color:#000; background-color:#fff; font-family:verdana, helvetica, sans-serif;font-size:10pt"><div><div>Hi folks,</div><div><br></div><div>I'm currently involved with a prospective project to retrofit an existing urban office building in a robust four-season climate. The building is roughly 60 floors, circa early 1960's, with an original single pane, non-thermally-broken aluminum curtain wall, and anodized aluminum spandrel panels. We don't have exact glazing specs yet, but COG is likely in the range of: SHGC=0.43, Tvis=0.53, Uval=1.00<br></div><div><br></div><div>Here's the question: If you wanted to retrofit the facade to improve overall building energy / occupant comfort (heating, cooling, solar control, daylighting, MRT adjacent to glazing, etc.), <u>but were required to retain the original glazing (for architectural considerations, or due to impracticality of complete facade removal with existing tenants)</u>, what
options might you pursue? Additional potential constraints of note (still to be determined) may include: mullion depth limitations, structural facade load limits. Also worth noting that the building's rectangular plan features a SW-facing long-axis orientation, so spring-through-fall cooling loads are likely to be enormous. Finally, if a second skin solution is to be pursued, we're also keen to keep an eye on condensation issues.</div><div><br></div><div>What's the latest, greatest thinking in this arena? Suggestions / comments much appreciated....</div><div><br></div><div>cheers,</div><div><br></div><div>Adam</div></div></div></body></html>