We recently replaced the downstairs windows with triple pane glass (trying to cut down on noise and drafts), but the upstairs windows are still double pane and in decent shape. Honestly, I wasn't expecting much difference, but downstairs feels noticeably quieter and warmer now. Um, got me thinking maybe mixing window types isn't such a bad idea after all. Anyone else have experience with this or maybe other window hacks that worked out surprisingly well?
Mixing window types can work, but I'd be cautious about assuming it's always beneficial. Triple pane downstairs makes sense because that's usually where noise and drafts are most noticeable—street noise, foot traffic, etc. Upstairs, though, you might not see the same benefit since noise and drafts tend to be less of an issue higher up.
One thing to consider is condensation. Triple pane windows downstairs will have a different thermal performance than double pane upstairs. In some cases, this difference can lead to moisture issues upstairs if the humidity isn't managed properly. I've seen situations where homeowners upgraded only part of their windows and ended up with unexpected condensation upstairs because the warmer air from downstairs rose and hit the cooler double-pane glass.
If you're going to stick with mixed windows, just keep an eye on humidity levels and airflow. Maybe invest in a decent hygrometer for upstairs rooms and make sure your ventilation is adequate—bathroom fans, kitchen exhaust, etc. It's not necessarily a deal-breaker, but something worth monitoring closely...