We like to camp alot creekside way back off the trail around here in VA.
I have a washing machine 120VAC water pump that is connected to an old heater unit from a car and have a 12VDC Fan behind it. I can run cold water being sucked in from the creek through the water heater cores and then back to the creek. I have two 50-foot water hoses that I throw one end into the water and connect the toher ends to the heater core/water pump connections. I have all of this mounted inside a old cooler box I don't use anymore. We can blow low 7Os water temps into the trailer all night long with hardly any draw from the battery bank. Surprising how cool that works out for us.
We also love to use our roof mounted fantastic fan pulling in cool night air through small opening in the window flaps. Once the sun goes down it gets pretty cool back in the woods creekside somewhere...
Like I indicated above my duty Power inverter is a 600WATT Pure Sine Wave unit directed connected within 5-6 feet away just inside the trailer to my 255AH battery bank and I run two multi-head 120VAC receptacle plugs extension cords from the two 120VAC connections with one going to the Home Entertainment area and the other cord going to the back of a table top near where we sleep. The extension cords all run behind things and are completely out of site... This saved me from having to tap into any of the trailer wiring... This is where we plug in our chargers for cell phones and computer etc and run several small wattage 120VAC items we have. Since our Inverter is pure sine wave type we don't have to worry about what gets plugged into them - nothing burns up... I just leave everything plugged into the 600WAT Power Inverter even when we are on shore power.
Our lightning is all LEDs so we don't have much of a 12VDC power drain for all of the necessary things.
We do very well with our 600WATT Pure Sine Wave Power Inverter (AMAZON)... Been doing this since 2009 in our Off-Road POPUP camper...
Roy Ken