low-e glass replacement
https://03aab3sckx.birchreport.com/posts/why-a-free-window-estimate-is-the-first-step-to-a-smarter-replacement
We had to replace a few panes of low-e glass after a hailstorm, and it made a huge difference in how the house feels. The new panes keep the heat out much better, and I've noticed the cooling bill is lower. It's a specific job though, needing the right coating to reflect UV rays, not just any double-pane.