Just about anything can be used for cold air return as long as it won't get sucked into the blower like thin plastic like plastic bags and such.

Ha.Nathan- I am in ND, I do not work the rotating schedule, Im 5am to 5-7pm. mon-fri.

Thank you @Larry Fried

Quote from @Ashton Fry: Hello BP,I close on a property that will be a STR at the beginning of April in Jacksonville Beach, FL.

If the federal gov't defaults on it's bond payments, we've got bigger fish to fry, so the "risk" simply isn't a factor.I sent "happy birthday" cards in the mail every single week to all my past mortgage clients, and for the last several weeks I've included a gov't flier about I Bonds in it.

That's also very useful info about the rodents--one more reason to take preventative measures.I was thinking of it from the perspective of how materials break down (especially with heat/cold cycles)--typically, rubber and plastic type materials break down faster in a car's engine bay than the metal materials, for instance...which makes me think pex would break down (become brittle) faster than copper....but, I'm no engineer, so who knows...

They can keep doors closed, or crack windows, or intentionally take plastic off windows, or intentionally cause the heat to turn off before the authorities show up to take measurements.

ALL plastic with proper slope will give you more trouble free use. 

The neighbor has pictures of the damaged wall before and after the owner personally removed about twenty asbestos shingles where the building had been hit and he has collected some pieces he picked up off the gourd and has put them in a plastic container.

Simply give them a written notice that says, the fire pit thing must be removed and it's not permitted for use or storage on the property,  And if they grill the grill use is to be 10 feet from building and set a storage spot for that when not in use.. also make sure they store the charcoal, and lighter fluid in a plastic bucket with lid, outside.