I don't know all the answers, but I can tell you that if you look at storm windows, they have tiny weep holes so that they're not 100% airtight. I believe that's how you prevent condensation between the panes.
So, a partial answer is that your space between panes shouldn't be totally airtight.

Hi wible1,

I know this to be a common problem w/sidelights. However, more contemporary sidelights are much thicker or are built double-paned. Unless your sidelights are made of glass that's NOT meant for that purpose, it's a little 'difficult' for me to understand why you're feeling so much cold air.

Are you SURE the air is radiating through the stained glass and not around the door, itself? I mean, there isn't much glass to sidelights. The effect you are experiencing isn't out of the ordinary, but you're making sound like the air is almost 'blowing in'. This type of thermal transfer is normal where there is a 'surface' (which is your glass) between a cold surface (outside) and a warm surface (inside). The 2 'elements' will try to equalize each other with the cold air moving towards the warm air (since cold air sinks), and the warm air moving towards the cold air (since warm air rises.)

As far as installing a storm door, sure, you could do that but I'm not aware of a single-swing storm door for an entry door w/sidelights where the storm door will 'enclose' the entire entryway. Yes, you can get a storm door for just the entry door but your problem INCLUDES the sidelights.

As an aside, we bought our home w/an entry door and sidelights. We demolished that in place of double-entry doors. We then installed double storm doors too. Aestetically, it looks nice. (We have full-oval, solid oak entry doors.) This does pose its own set of 'issues'. (I'll leave that alone unless you're contemplating this approach. I will assume not.) I'm only mentioning this because the only way we could get a storm door was to go w/double-entry doors. The storm doors are full-view doors so you can 'enjoy' the doors from the outside too.

As far as insulating your sidelights, assuming the entry door and sidelights aren't leaking, I wouldn't do it. You could start a condensation/mold/mildew situation. And besides, they'd look kinda funny. If these sidelights and the entry door are part of the home's character, beings that you own an 'old house', you may end up just consider it something you need to live with.

If you have more info to offer, perhaps I can say more to your questions. My best to ya and hope this helps.

Jay J -Moderator

PS: God Bless America!

Thanks for the reply, Jay. A little clarification - I may have exaggerated on my explanation of the air infiltration; the stained glass sidelights and transom appear to be very old (the house is 80 years old). My concern is not that I can feel a "breeze", but that the type of glass used is single pane and seems like a poor insulator, based on the coldness I can feel radiating through (for the reasons you described in your second paragraph). Since I am in the process of replacing my old aluminum windows with vinyl insulated windows, I wanted to do something in these areas since I feel I'm losing a lot of heat there, but still keep the same look. I wasn't considering a storm door, only a fixed frame of glass over each sidelight/transom, essentially making them double paned. My question was whether to consider installing a piece of glass within moulding and seal the edges in caulk, or to consider a fixed "storm window" over each section, assuming they make those sizes. I understand your concern about moisture, but wouldn't meticulous construction of the frame and silicon caulk prevent that?

Thanks again.

Hi wible1,

I'm sure I overstated the 'situation'. SOmetimes, I exadurate to make my 'point'.

Anyways, I think that if you were to build your own double-pane, you'll end up w/mold/mildew because the 'gap' isn't under vacume. Sure, 'trapped air' is a great insulator but you'll have moisture issues. As the air heats and cools, moisture and air will be 'moving' in and out of that space. Unless you can create a vacume and have a perfect seal, I think your efforts will prove unuseful.

At the same time, you could still have a 'what the heck attitude'. You have nothing to loose except a few $$$ and a little time. WHat I'm saying is that in spite of my $.02, try it anyways. You never know - It may just work (and I'll be wrong for the 2nd time today!)

My best to ya and hope this helps.

Jay J -Moderator

PS: God Bless America!