I actually wasn't aware LTT did a video on Peltier coolers.

Just to clarify: Peltier coolers are heat pumps, they move heat from one side of the plate to the other. This means that like any other cooling system they don't generate cold, they remove heat. That must then be dissipated into the air by a more traditional cooler.

They're more interesting I think for power generation. The same principle is used to power the Mars rovers using a brick of plutonium (called a "radio-thermal generator"). It's really cool.

LTT more recently did a video on a piezoelectric fan. If you haven't seen it you should check it out, it's also cool.