Foggy windows driving me nuts - what’s actually normal?

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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“nothing beats swapping out the whole window... which my wallet is still recovering from.”

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.

Yep, I’m right there with you. First winter in my new place and I learned real quick that north-facing bathroom windows are just… a whole thing. Mine isn’t even that old (built in the 90s), but the aluminum frame gets so cold, it’s like it’s daring the hot shower steam to come at it. I started wiping down the sill every morning just to keep the little puddles from growing into something out of a nature doc. No mushrooms yet, but I did find a patch of what I think was mildew trying to take over behind the shampoo bottles.

I looked into new frames too, but wow, those quotes were not friendly. Decided to try a stronger extractor fan first - one with a humidity sensor. It helps, but like you said, it’s never perfect. Sometimes I’ll crack the window just a bit, even in January, and it still fogs up. I guess the only “normal” is that there’s always going to be some condensation unless you want to shower in the dark and cold.

Funny thing, I thought moving into a newer house would mean less of this kind of hassle, but old or new, moisture finds a way. My neighbor swears by keeping a little portable dehumidifier running, but the noise drives me nuts. I’m starting to think the real trick is just not letting it sit - wipe it down, keep the airflow moving, and hope for the best.

Maybe someday I’ll pony up for the fancy frames, but for now, I’m just happy when the window’s dry enough that I can actually see out in the morning.

That’s pretty much my life every winter - north-facing window, aluminum frame, and enough condensation to water a small garden. I tried the dehumidifier thing for about a week, but it sounded like a jet engine and honestly, I’d rather risk a little mildew than lose sleep. I’ve just accepted that wiping down the sill is part of my morning routine now, right up there with brushing my teeth.

I did wonder, though - has anyone actually found a permanent fix for this without dropping serious cash? I’ve heard about those window insulation kits (the cling film you stick on with a hairdryer), but I’m not sure if they do much besides fog up even faster. And those fancy triple-glazed units are way out of my league for a bathroom window.

Curious if anyone’s tried the old-school trick of putting a bowl of salt or rice on the windowsill to soak up moisture. Seems a bit like wishful thinking, but desperate times...

I’ve actually tried the rice trick - ended up with a crusty mess and still had puddles on the sill. My neighbor swears by those window film kits, though. Says it helped a bit but didn’t totally solve it. Ever notice if certain days are worse than others? For me, it’s always after a hot shower, even with the fan running.

For me, it’s always after a hot shower, even with the fan running.

That’s basically my life every winter. The fan in my bathroom might as well be decorative at this point. I used to think I was doing something wrong, but turns out, you can run the fan for an hour and still end up with foggy windows if it’s cold outside and the humidity spikes inside.

The rice trick made me laugh - tried that once with a leaky windowsill and all I got was a weird science project. Window film kits are decent for drafts, but they don’t really deal with the moisture inside. They just make the glass a little warmer, so less condensation forms, but it’s not a silver bullet. If you’ve got single-pane windows (like me, in my 1950s ranch), it helps a bit, but you’ll still see fog when you’re cooking pasta or taking long showers.

Day-to-day, I notice it’s worst when the temps drop suddenly or after I’ve been drying laundry inside (bad habit, I know). Hot showers definitely make it worse, especially if you close the door and trap all the steam. Even with a “good” fan, it sometimes can’t keep up if your house is sealed up tight for winter.

If you want to get nerdy about it, it’s all about dew point - the temp where the air can’t hold any more moisture, so it dumps it on your coldest surfaces (hello, windows). Newer double-pane windows help a lot, but they’re not cheap. I finally caved and bought a small dehumidifier last winter. Not glamorous, but it actually made a difference. Still get a little fog, but nowhere near as bad.

Honestly, I think a little fog is just part of life unless you want to spend big bucks on upgrades. Anyone else have luck with those moisture absorber tubs? I’m skeptical but tempted to try one just to see.

I’ve wondered about those moisture absorber tubs too. I see them at the hardware store and always think, “Do these actually do anything in a regular-sized room, or are they just for closets?” Part of me suspects they’d fill up in a few days and you’d be back where you started, especially when the humidity really kicks up.

On the topic of dehumidifiers, did you notice your heating bills go up when you started using one? I keep hearing mixed things - some folks say it takes the edge off the dampness so you can actually run the heat a little less, but others say it’s just another appliance sucking up power. I’m tempted, but my house is drafty enough that I’m not sure it’s worth it unless I seal things up better first.

I’ve got single-pane windows too (1958 split-level here) and honestly, window film helps with drafts, but like you said, not much with condensation from inside. I even tried cracking a window after showers, but then the bathroom turns into a fridge and nobody’s happy.

Curious if anyone’s had luck with swapping out just one or two windows to double-pane instead of doing the whole house. Does it make enough difference in those rooms, or does all the humidity just find its way to the next coldest spot? My neighbor did that in his kitchen and said it helped some, but he still gets fog on his old windows down the hall.

Are we all just fighting a losing battle unless we go full renovation mode? Or is there some magic combo of habits and gadgets that actually works for old houses?

- Agree on the tubs - fine for closets or under sinks, but they’re useless in a big room. You’d need a ton, and you’d be dumping them constantly.
- I use a dehumidifier in the basement. Didn’t notice much change in heating bills, but it does make the air feel less clammy. Still, it adds a bit to the electric bill.
- Swapping one or two windows to double-pane helped a lot in those rooms, but yeah, the moisture just moved to the next coldest window. Not a total fix, just less annoying in bedrooms.
- Old houses are always a juggling act. I do window film, keep a fan running after showers, and try not to hang laundry inside. Not perfect, but better than nothing. Full reno is $$$, so I’m just patching things for now.

Totally relate to the “moisture migration” after upgrading a couple windows - felt like a game of whack-a-mole at my place too. I’ve found that air sealing around the frames (not just the glass itself) made a bigger dent than I expected. Still, old plaster walls seem to find sneaky ways to let humidity through. The tubs are a joke in my drafty dining room, but I keep one under the kitchen sink just out of habit. Sometimes I wonder if I’m just rearranging the condensation instead of solving it... but hey, at least the windows aren’t dripping onto my bookshelves anymore.

Man, you nailed it with the “whack-a-mole” comparison. I’ve seen folks seal the glass and totally forget about those sneaky frame gaps - like patching a leaky boat but leaving the plug out. Honestly, old plaster’s like a secret agent for moisture. I once spent a weekend chasing condensation only to realize my kitchen vent was blowing right at a cold spot… felt like I was just moving puddles around. At least if the books are safe, you’re ahead of where I started.

That’s pretty much my experience too - chasing moisture around like it’s got a mind of its own. I’ve tried every trick, from caulking the obvious spots to running dehumidifiers, but it always finds another way in. Sometimes I think these old houses just breathe weirdly, no matter what you do. I’m not convinced there’s ever a perfect fix, especially with original windows and plaster. At this point, if the sills aren’t rotting and the paint isn’t peeling off, I call it a win... even if the glass fogs up now and then.

I get what you’re saying about old houses just doing their thing, but I can’t help thinking foggy windows are more than just “normal.” I mean, sure, some moisture is expected, but if you’re seeing it a lot, doesn’t that mean there’s still something off? I started out just accepting it too, but after digging into some building science stuff (and obsessing over YouTube repair videos), I realized a lot of the moisture in my place was from things like cooking or showering without enough ventilation. Once I put in a better bathroom fan and actually used the kitchen vent, the fog cut way down. Maybe it’s not about fighting the house, but changing a few habits? Just my two cents - old windows or not, I think we can do better than foggy glass all winter.