Bug Screens keep critters out of the openings of the Casita’s appliances. Mud Dauber Wasps are a particularly nasty bug that love to camp in Casitas too. One time I opened the refrigerator access panel and there was a big mud nest on the cooling fins. Luckily the wasps were gone, so it was easy to clear out.
I use screens on the furnace intake/exhaust, hot water heater cover, and the top panel for the fridge. I left the bottom fridge panel screen-less to help with airflow. Critters like warmth, so they’re more likely to go in the upper vents where the cooling fins are.
They install with springs and a little tool that reaches in and hooks them to the grill. It’s a little tedious, but once attached, they’re on pretty well. The fridge covers are held on by small zip ties.
You can buy all the screens you need by clicking on the photos below. Here are furnace screens if you have a gas furnace:
Water heater screen:
Fridge vent screens, you need both sets and they may require trimming: