I can't believe how much cooler the rooms are now with our window inserts, especially the ones that face west. One of them was set up as an office and I dreaded working in there during the day due to the heat. You either had to turn your air conditioning thermostat down (for the whole house) or turn the ceiling fan on high, which blew your papers all around. Now it's totally comfortable! An added plus is the sound from the street and a nearby freeway is gone.