Chasing that “perfect” window is like trying to find a quiet spot at Thanksgiving dinner… probably not happening.
That’s a solid analogy, but I’ll say—sometimes folks overlook humidity control inside the house. Even with new windows, if you’ve got a lot of moisture in the air (cooking, showers, plants), you’ll see fog on the glass when it gets cold outside. I’ve seen people chase seals and caulk for years, when a simple dehumidifier or cracking a window during steamy activities helps just as much. If you’re only seeing condensation on the inside, it’s usually not a window failure—just normal physics at work in older homes. Water *between* panes, though? That’s when you’ve got a real seal issue and need to look at replacement glass or sashes.
If you’re only seeing condensation on the inside, it’s usually not a window failure—just normal physics at work in older homes.
Is it always just “normal physics” though? I get the humidity thing, but I’ve got a 90s house and some rooms fog up way more than others, even with similar use. Could it be poor insulation around the window frame itself? Or maybe old weatherstripping? I’m just never sure when it’s worth actually worrying versus just running a fan.
Not sure I totally buy the “just physics” thing either. I’ve got a place from ‘97 and the bedrooms on the north side fog up way more, even if I barely use them. For me, it turned out to be old, shriveled weatherstripping—felt around the frames and could literally feel a draft. Swapping that out helped a ton. If you’re noticing it’s always the same windows, I’d check for tiny leaks or gaps. Fans help, but they’re just treating the symptom, not the cause...
Had a similar thing in my 80s split-level—north-facing rooms were always the worst offenders, even when barely used. I kept thinking it was just “cold air meets warm air” but it never made sense why only certain windows got bad. Like you said:
If you’re noticing it’s always the same windows, I’d check for tiny leaks or gaps.
Totally agree. In my case, I found one window where the old caulk had basically crumbled away on the exterior. Couldn’t see it from inside, but outside there was a gap big enough for a pencil. Resealed that and the fogging dropped off almost overnight.
Fans help a bit, but if you’ve got cold air sneaking in, you’re just moving the problem around. Ever try one of those thermal cameras? Borrowed a cheap one from a friend and it was eye-opening—could literally see the cold spots around the frame.
Curious if anyone’s noticed if double-pane vs single-pane matters much? Mine are all double, but I still get fogging until I deal with the drafts.
Funny, I always thought upgrading to double-pane would be the magic fix, but I’ve still had condensation on a couple of them—especially on the north side like you mentioned. It’s wild how just a tiny crack or missing bit of caulk can make such a huge difference. Did you notice any change in your energy bills after sealing up that gap? I patched up a few spots last winter and swear my furnace didn’t kick on as often, but maybe that’s just wishful thinking.
About those thermal cameras—are the cheap phone add-ons actually worth it, or is it better to rent a “real” one? I’ve been tempted to try one out, but not sure if the $200 gadgets are more than just a fun toy.
One thing I can’t figure out: does it matter what kind of window frame you have? I’ve got some old aluminum sliders and some newer vinyl, and the aluminum ones always seem worse for fogging, even after sealing. Maybe it’s just the way they conduct cold?
I’ve actually had kind of the opposite experience with the energy bills after sealing gaps. Maybe my house is just draftier than most, but I didn’t notice a huge drop—maybe a few bucks less per month, nothing dramatic. Could just be my old furnace working against me, though.
About the thermal cameras, I tried one of those phone add-ons from a friend, and honestly, it was cool to see where the leaks were, but I’m not sure it was super precise. The image was kind of fuzzy and didn’t really help pinpoint tiny drafts. Renting a higher-end one might be worth it if you want to get serious about sealing things up.
For window frames, yeah, aluminum is definitely colder to the touch. I think it’s just a bad insulator compared to vinyl or wood. Even with double-pane glass, the frame itself can get chilly and cause condensation. I’ve heard some people add foam strips inside the frame to help, but I haven’t tried that myself.