3 ms·Insulation doesn't substitute for AC if the lows aren't low enough to cool thing down at night.by moultano 5y agoInsulation doesn't substitute for AC if the lows aren't low enough to cool thing down at night.Jcowell 5y agoNot to mention that an AC installation is much cheaper than tearing a building down and building to back up.bjourne 5y agoNo, not entirely, but it complements AC. Proper insulation means that much less energy is needed both to cool and heat a building.