Multi-panel doors in the PHPP?

[Markus Barrera-Kolb]

So far no responses to my question about how to deal with trapezoidal windows in the PHPP, and here's yet another PHPP window / door question:

For multi-panel doors, where there's just one frame but multiple door panels – sashes, if you will – how should we be handling the PHPP entries (a two-panel lift & glide door would be one example)? One frame (jamb), but two doors,and two insulated glass units with the accompanying spacers & resulting thermal bridges. Doesn't seem like this could be modeled accurately with a single entry in the PHPP – do we break such a unit down into one entry for each door panel? If so, I assume that the U-frame given by the manufacturer is accurate for the jamb+sash together, but would it apply to just to door edge without the jamb? Has anyone dealt with this? Thanks...

Cheers,

Markus

[Graham S. Wright]

Yes generally each sash or panel would be entered as a separate window. That will properly account for the fact that the glass is R-7 but the frame is R-4, or whatever.  After that you can look at what if the door edge is actually R-5 and see if its making enough of a difference to be worth pinning down.

-gw

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[Markus Barrera-Kolb]

Thanks Graham – so you'd take the same approach for a sliding door and make a separate entry for each of the two door panels, even though there's no frame in the center? I guess then you'd make multiple entries on the WinType sheet to represent frame widths for left & right panels that include and exclude the jamb, correct? And it might be good to know whether the door frames overlap when in the closed position... I think I might be entering quite a few more frame types than the 11 rows that are currently available on that sheet!

[Rob Harrison AIA]

I did just as you describe for the big lift-and-glide on Park Passive. Each panel was a separate entry, with different jamb widths depending on position. There's a "frame" around each panel, with corresponding heat loss, even if there's not a jamb. 

Rob Harrison AIA, CPHC

http://harrisonarchitects.com

[Graham S. Wright]

Right. 

Usually it turns out there is also something about the shading that is different between the panels as well.

 

If you have a lot of frame types and want to simplify you might start by using the worst performing one for everything and see if you can get away with it. 

BTW divided lites and SDLs are different. There it usually makes more sense to derate the center of glass properties. 

Sent from my iPhone

[Rob Harrison AIA]

Good point Graham. The panels at the edges of the opening will be shaded by the wall reveal. I averaged the reveal on both sides for those panels. As Graham suggests its a question of finding something you can do (average, adjust the quantity multiplier, create a new window type, etc) to approximate the effect of this and that. 

Rob Harrison AIA, CPHC

http://harrisonarchitects.com