Hi, I have 7 north facing 40 year old Anderson double hung windows. One lower sash constantly has condensation on it, winter or summer, on the inside. None of the other windows have ever had any condensation on the inside. The blinds are open and there are no curtains to block air flow. It is only the lower sash not the upper. It is the second story window with windows above and below it. Any ideas why? Thanks, Mike

Windows typically have a thermal break in the frame so that cold cannot transfer easily to the inner frame and glass surface. It sounds to me that that thermal break in the lower sash is compromised and causing he inner glass surface to get cold enough to reach dew point.

Are there any water pipes in the walls near it or in the room? What's the room used for?

No water pipes, a bedroom

Moisture likes to condense on the coldest spot that it can find. For some reason that one sash seems to be a cold spot.

By "On the Inside" I assume you mean between the two pains of glass.

If this is indeed the case, the the vacuum between the two pains has failed. Nothing to do but replace the glass, the sash, or the entire window.

No, on the inside of the window, can be wiped dry.

If it's only one, I would still go with a broken seal.

You can Check the humidity in the house, etc. But one out of seven indicates that "One" is defective.

Do you have AC,

Heat source, Boiler-Base Board, Forced air, eclectic base board, slab heat?

HVAC ducts?

(going w/ defective window)

Check to see if the weather strip is still good on the blind stop or at the meeting rail, see if it's ripped, torn, or missing.

Nitrogen leak

Shower timer.

Or argon

Whatever the chit is they put in those

That was a thread almost as long as stupid as the ammon bundy thread. And the jade helmers that made it

All windows except the bedroom windows were replaced with the same brand at the same time back in the late '90s

The side by side double north facing windows in our kitchen get condensation buildup in the summer sometimes depending on outside humidity. The also north facing single dining room window and side by side double windows in the living room never have yet. My guess is the kitchen window seals no longer seal well and since there is a AC/ heat vent directly above and center of the kitchen windows, the cold AC air blowing directly on the window causes any humidity vapor to condensate on the colder glass.

Buncha cashed up high rollers.


We had an estimate done on windows 15 years ago.



Would have been cheaper to get a double wide rolled in.


Would have increased our square footage too.

Hell with that.

Thanks for the replies, I'm going with the defective window analysis.

Mrs slumlord installed all of our new double tilt in insulated, etc windows

The little man from the bldg supply came out and measured everything. Took about a month for them to be made.

Cost about $220 each.

We’d do a couple every afternoon getting home from our worky jobs. I’d tear out the single pane sashes and tracks, she’d install the new windows. Level and screw them in. She ran all the trim thru the table saw and sealed them up and painted the new outside brick moulding.


Saved us about $8,000

Window companies, (the installers) are pure ripoff scum.

$220 each, would put junk like that in a Schit house at the hunting shack