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Last winter I ordered window inserts

user-753427 | Posted in Energy Efficiency and Durability on

Last winter I ordered window inserts to beef up my double-pane, double-hung windows and I think the results were good. In the late spring I also installed double honeycomb cellular shades to abate summer heat (inserts in storage at this point).

The window inserts I use are from [insert name of company here]. They come with a heavy gauge film mounted on a frame and a foam gasket around the frame for fitting and airsealing. Essentially, they are seamless interior storm windows. The insulating shades are a close fit within the window frame.

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  1. GBA Editor
    Martin Holladay | | #1

    Do you have a question, or are you just promoting the name of a website [the one that was replaced by the comment in brackets]?

  2. user-753427 | | #2

    I have no interest in promoting the website. I fit my question in the question box and the site requires something in the more info box, so for reference sake I just added the website. My question is simple, with the insert in place, is there an added benefit to having cellular shades dawn closed as well (to the inside of the inserts)?

  3. GBA Editor
    Martin Holladay | | #3

    OK - got it.

    So, you have interior storm windows. Do the "cellular shades" provide an airtight seal at the sides and the top? Or do they allow air to flow between the shades and the interior storm window?

  4. user-753427 | | #4

    No air seal. Even the systems that provide an air seal I have found to be suspect. There's really no seal with most of those that I have seen, just a tighter fit around a track. The inserts are quite a fit though. So, I realize that the air flow around the shades continue to exist, but continue to wonder if there is a game from radiant heat loss/retention.

  5. GBA Editor
    Martin Holladay | | #5

    If air can flow between the shades and the interior storm window, there will be little (if any) benefit from drawing the shades closed during the winter.

    If you want to improve the thermal performance of your window during the winter with an interior shade, then you should install a window quilt equipped with side tracks, an airtight valance at the top, and a Velcro seal at the bottom.

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