I live on the second floor in a tall building. My previous air conditioner (AC) was getting hit several times with pigeon poop. Not only the poop was going inside the unit, or getting stuck on top, but also making a loud noise. Hoping one day manufacturers will have some kind of built-in protection on top the unit instead of leaving it open (I know it's to help ventilate the unit). Until then...

Ideally I'd like something that would be tilted so poop (and other stuff) can slide down away from the AC. And also would allow rain to clean it. Something that is removable for easy replacement when it gets too dirty would be nice too.

I know AC units are designed to stand this. However I remove my AC from the window every winter (so it frees up the window, etc.) so of course I'd like to protect it from getting more than dust/leafs.

I don't want to simply fully cover the top of the AC with foam. I think this might not even be safe. Something that would protect the cover while still leaving space for ventilation, and that I could remove and replace with a new cover every summer (that is, not something permanently attached to the window). I was thinking about using brackets attached to the AC, with some kind of material on top (acrylic might be too fragile in a stronger wind/storm, for example?).

I'd like to hear some ideas!


  • Since you live in an apartment, I assume you have limited access to tools? There are so many ways to create a cover for the A/C, so you might want to focus on some of the details using a material you are comfortable with.
    – JPhi1618
    Feb 4, 2020 at 21:28
  • 2
    i would stick some contact paper on in the spring, and remove it in the fall. you could also likely use sheet plastic and magnets. Or put the AC in a tight-fitting plastic bag first, then cut ports for air exchange. You can strip off the "condom" before storing.
    – dandavis
    Feb 4, 2020 at 21:32
  • fun fact: the white stuff is pee, the little dots in the middle are the only poop.
    – dandavis
    Feb 4, 2020 at 21:33
  • 1
    Attaching things to the top surface of the A/C unit is not the way to solve this. It needs an air gap. Feb 4, 2020 at 21:38
  • Actually there are fans to move the air through the sides and back the top won’t be a problem. With most units this is solid and MFG’s recommend spike strips to deter birds and 4 legged animals like squirrels.
    – Ed Beal
    Feb 4, 2020 at 23:16

1 Answer 1


For a long time I had several window ac units and had a similar issue with pigeons, a guy down the street raised them and they loved my house for some reason, I found a piece of sheet metal at an angle kept them from landing on them and when they perched on the gutter as they start to fly they would poop, the angled metal worked I used self adhesive Velcro to hold it in place, when it came time to pull them in the winter I popped them off and cleaned them in the bathtub, I did have to paint 2 of the 3 on the 3rd or 4 th year and after that I found motion activated sprinklers (I still use those today to keep birds out of my pool).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.