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.
Funny, I had almost the exact same experience with those phone thermal cameras—neat gadget, but it felt more like a party trick than a real diagnostic tool. My old aluminum frames are always cold too, and I swear they attract condensation like a magnet. Tried the foam strips last winter and they helped a bit, but honestly, nothing beats swapping out the whole window... which my wallet is still recovering from. Sometimes I wonder if these little fixes just buy us time with old houses.
- Totally get the “party trick” vibe from those cameras—fun, but not exactly life-changing for old windows.
- Same here with aluminum frames. Even with foam strips, it’s like fighting a losing battle some days.
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Couldn’t agree more, but wow, it hurts financially.“nothing beats swapping out the whole window... which my wallet is still recovering from.”
- Do you find the condensation is worse on certain windows or rooms? For us, the north-facing ones are always the worst, no matter what I try.
North-facing windows are a pain, right? In my place, the bathroom window gets it the worst—sometimes it’s like a mini rainforest. I’ve tried cracking the window, running fans, you name it. Honestly, those aluminum frames just seem to sweat more than anything else in winter. Swapping them out made a difference, but yeah… my savings took a hit.
North-facing windows have a special talent for collecting condensation, especially in bathrooms. I’ve seen more than a few “indoor rainforests” in my time—one job, the client’s window sill was practically sprouting mushrooms. Aluminum frames don’t help; they’re like little highways for cold air, and when warm, steamy air hits that metal, you get instant sweat. I swapped mine out at home for composite frames last winter and noticed a big drop in moisture, but yeah… the bill nearly made me need to install a fainting couch.
Even with new frames, though, if your bathroom’s getting hit with long hot showers and not enough airflow, you’ll still see some fog. A decent extractor fan on a timer helps, but it’s never perfect. Sometimes I think old houses just want to remind us who’s boss. At least you’re not alone—seems like every time I work on a north wall in winter, I know what’s coming.