"How to Seal an Unused Window AC Slot and Prevent Birds: Practical Home Tips"

With many households switching from traditional window air conditioners to split units for energy efficiency and aesthetic reasons, the old wall slots often become forgotten dead zones. However, as one homeowner recently shared in a Facebook renovation group, these vacant spaces can quickly turn into an unexpected problem — bird droppings.

The user sealed the indoor portion of the AC cavity, but the outdoor extended ledge became a resting spot for birds. Over time, the accumulation of droppings created a mess that's hard to clean and unpleasant to see.

So, what solutions did the online community offer? Here are the most practical and proven ideas:

✅ Top Bird Deterrent Suggestions from Homeowners

1. Custom Stainless Steel Mesh Covers
   A tailored square frame with steel mesh can be installed over the exterior slot. It's effective, clean-looking, and a one-time investment (~NT$3,000).

2. Install Sloped Covers (Wood or Acrylic)
   Creating a steep angle makes it difficult for birds to land. These can be mounted directly to the wall or inside the cavity.

3. DIY Wood Box Enclosures
   Enclose the cavity with treated wood, nailed and sealed for durability.

4. Re-Seal the Exterior and Remove the Inner Panel
   Reclaim a bit of indoor space while ensuring birds can’t access the ledge anymore.

5. Demolish the Unused Slot Altogether
   The most permanent solution — remove the unused structure completely.

Bonus Tip from the Pros: Camphor Balls

According to one experienced user, placing mothballs (camphor) near the opening effectively keeps birds away. Replace every 6 weeks for consistent results.

“I tried CDs, red paint, windmills, and spikes — none worked. Only camphor balls made a difference.”

Editor’s Pro Add-ons:

• Install Ultrasonic Bird Repellers: Emits frequencies birds dislike.

• Use Reflective Stickers or Foil Tape: Light reflection can scare off birds.

• Hire a professional to rework the ledge: Consider converting it into storage or garden decor.

Final Thought

Leaving bird-prone spaces unattended not only affects home cleanliness but could lead to potential health hazards. Acting early saves time and keeps your exterior pleasant and functional.