Register Booster Fan for 4" x 10" Register Holes, Quiet 10-Speed AC Vent Fan with Remote & Thermostat Control, Improves Heating&Cooling, Manual Adjustable Louver, USB Powered for Floor Wall Ceiling

It depends on what kind of heat you’re battling and how much you’re willing to put up with. In California, we have already hit a 100° F day. Since it gets cold at night, I open my windows at night and try to create a cross breeze. If the apartment is not cool enough in the morning, I will blast the AC after I close the windows. It depends on how many windows you have. I live in a corner top unit and have eight windows. It’s also more expensive for me to run the AC between 5 and 8 p.m. because those are “peak hours”. The measures you take to keep out the heat are greatly determined by how much sunlight you are willing to sacrifice. The window tinting clean film is helpful, but not a game changer. I would rather have them than nothing though. I have found that the blackout material that goes up with Velcro really blocks out the light and heat. The most important part is to make sure it is flush against the wall. Actual blackout curtains are helpful, but again you do not want light/heat seeping in. On the windows where I have only used thermal insulated blackout curtains, I could literally feel the heat come in at the bottom of the curtains. I ended up using thumbtacks to keep them flush against the wall. If you have central air, there are vent/register boosters that run a ran and hopefully propel the AC better. They do have to be plugged in though. Lots of fans. To sum up: — window tint cling film 4/10 https://a.co/d/06Y6F0cZ— thermal insulated blackout curtains 8/10 https://a.co/d/091KgBCK— blackout “curtains” with Velcro 9/10 https://a.co/d/068BX9Cq— register booster fan 3/10 if used with nothing else https://a.co/d/07ePfL80— Oscillating shark fan can be turned into a table top https://a.co/d/0dD2rDk8 7/10— Oscillating Woozoo table top fan. Was $26 in Costco though 7/10 https://a.co/d/0gyrGgLl