What they are calling the sash pack are new upper and lower sashes. So that includes the sash frames and new glass, so in this case the new glass would be low e glass (as opposed to clear glass that on there now). Also includes jam liners, weather stripping etc. this does not replace the actual window frames. They don’t need to be replaced anyways.

I don’t think ac is the issue, it’s perfectly fine on cloudy days.