Replacing 1/16 glass in double hung wood windows

[cjra]

We have an 1890s Victorian, fabulous HUGE windows, which work great for natural cooling, but we're installing central a/c and heat. Some panes are broken and have to be replaced anyway, but what can we replace them with, without replacing the entire window (for $860/window!)?

What would be the most energy efficient, given the size - can't do double pane because there's not enough space. We can re-work the windows ourselves a bit to add an extra 1-2/16s of space to fit glass, but would such glass be any more energy efficient than what's there?

We have 14 windows - most 8ft x 3 ft (one is 8 ft x 6ft, and 2 are smaller). Eventually we'd like to make all more energy efficient, but for now, will just replace the broken ones.

Thoughts?

[Paul Franklin]

If I understand your question, you are asking if replacing 1/16 thick single pane glass with 2/16 single pane glass will save any energy.

For all practical purposes, no. Double pane glass saves energy because of the insulating air (or inert gas) space between panes, not because of the double glass.

Using low-e glass might help, but I don't think there is such a thing as single pane low-e because the coating is fragile.

There are companies around that will take your window sash, remove the glass, rout a deeper rabbet in the frames, and install double pane glass. IIRC it is a little cheaper than replacing the entire window with top quality windows, but more expensive than, say, replacing with a good grade of vinyl window. But if you want to retain the original look, this might be the way to go.

You could consider installing exterior triple track storms, but it would ugly up that lady. Best to fix the broken panes, and save your pennies for good replacement windows as you can affort them.

HTH,

Paul

[Duane Bozarth]

As Paul notes, replacing w/ thicker single-pane glass will make no discernible difference in thermal efficiency as glass is a pretty good heat conductor.

If these are the original windows and they're in good shape yet, I'd try real hard to preserve them for the originality of the house. If you're in a large metro area, it might even be possible to find a source for a glass that will more nearly approximate the original than modern glass. Depending on your intent on keeping the original character, of course.

It might be possible to have a non obtrusive set of storm windows designed that would help w/ the heat loss depending on the style of the windows themselves.

Other than that, I'd try to hold on until I could get a period-authentic looking replacement if I could possibly manage it.

(Struggling w/ similar problem w/ old farmhouse w/ 6' x 6' 1-over-1 double-hungs w/ leaded glazing in upper throughout the sitting room/parlor and 3x6 everywhere else downstairs...Temporarily I built storm windows for the big ones as they are no longer opened...what to do w/ smaller is still a quandary.)

[Roger Shoaf]

I worked over a couple of these once. I removed the frames from the window, scraped out al the old putty and replaced it. The old cotton sash ropes were shot so I replaced those with some new nylon rope.

I carefully stripped all the paint off the redwood frame and installed noce plastic weatherstrips. I even had to mill some new redwood bead strips as th eoldones did not survive the disassembly.

The upper sash had a radius on th etop as did the glass. While I was re-puttying the second window, I had leaned the first 2 sashes gainst the sill. a gust of wind came up and the glass broke in the upper sash with the radiused glass.

As the price of double strength glass was only a few bucks more than the single strength, I opted for the double strength and what I didn't figure was that the stuff weighs more too. I reinstalled the window and since the upper sash weighed more than it used to and I had slicked up the frame the uppes sash dropped. I had to take the sash weights out and added a few large fishing sinkers to balance.

The weather stripping cut down the drafts. You might want to add thermal drapes to cut down on heat loss also.

If anyone is interested, I will explain how I cut the radius on the glass.

[cjra]

Vinyl windows are not an option. This is in an historic district and even if we wanted to (which we don't), we couldn't use them.

What you describe is exactly what I was thinking of doing - 'rout a deeper rabbet', tho I think would still be hard to get double pane in there.

Storm windows are also out for the same reason, but also, the concern here is more cooling than heating (So Texas).

Thanks for the help.

[cjra]

A lot of the windows are in good shape, so we'll keep them as they are for now. Just working on the broken ones.

I'll see what kind of estimates I can get to replace just the glass. I really don't want to replace the windows. Good luck with your own quandry.

[Marilyn & Bob]

You'd be surprised what can be done with storms. They can be made almost invisible. Check with your local landmarks agency or not-for-profit. I'm sure that they have a list of firms in your area that can make something that looks acceptable to both you and the authorities.

[Duane Bozarth]

...

Depends almost entirely on how anal the local controlling body is...some are virtually impossible to get past...

[default]

If you can document the type of storm windows (if any) that were used when the building was new, you might be ok. Failing that, glass or plastic inserts that fit on the INSIDE accomplish much the same thing.

[cjra]

not-for-profit. I'm

thing.

I'm quite certain the only 'storm' windows were the exterior shutters (which we found underneath the house). This is Texas.... I'd like to put the shutters up and make use of them, but they don't let in light.

I think we're going to insulate the area around the window, and just fix the glass and rely on that.

Thanks all for the advice!