Asked on Jul 24, 2016

Should holes be drilled into my vinyl window frame for air unit?

by Michelle
I have no air in my house. I was given two brand new air conditioning units for my windows. I have vinyl windows. When the units were installed two holes were drilled in the bottom of the frame of the window. This was done to secure the unit. I am wondering was it a bad idea to drill holes in the frame? Could I have water seep into the wholes eventually? I am worried about damage to my walls.
Air conditioning unit in window in master bedroom.
  16 answers
  • William William on Jul 24, 2016
    I don't know why the holes were drilled. Window units just sit within the frame. Any gaps are sealed with foam rubber insulation material to prevent outside air penetration and water seepage from rain.
    • See 1 previous
    • William William on Jul 31, 2016
      The top lip on the unit usually has two holes for screws so the window can't be raised and the flexible side panels have a hole to screw them to the sides so they don't move. If the window can't be raised the unit can't fall out or be removed.
  • Shelley Shelley on Jul 24, 2016
    Also, it negates the warranty on the vinyl windows (if they still have one).
  • Jean Myles Jean Myles on Jul 24, 2016
    My window air conditioner ( ground floor ) has aa place on the front at the top to secure it. Then there is a L shape bracket that stop the window from being opened I remove the unit every fall and after 5years no leaking water or any problems at all
  • Michelle Michelle on Jul 24, 2016
    The windows have been in the house for years. The warranty is probably gone. The holes were drilled so a bracket could placed to stabilize the AC unit from falling out of the window.
    • William William on Jul 24, 2016
      The AC unit should have a lip at the to that leans against the window sash to prevent the unit from leaning and falling out the window, Some people place a 2x4 under the unit on the outside window sill to support it.
  • Sako Marlin Sako Marlin on Jul 25, 2016
    Also if there were no screws securing the unit anyone could open the window, drop the unit out and enter you home. I also screwed L brackets on the top of the window and the frame for extra security.
  • Rosezzzzz Rosezzzzz on Jul 25, 2016
    Window units that are not secured with metal brackets and often iron bars are regularly burglarized from homes and businesses in our town.
  • Annie Annie on Jul 25, 2016
    William is correct. There should be a lip at the top of the unit to secure it to the window. The side panels only help to create a seal and don't hold the unit in place. Also, be sure there is a very slight tilt (upper part of the a/c) tipped back so the condensation runs outside. Stay cool!
  • Barbara Barbara on Jul 25, 2016
    I would use a piece of wood to anchor the a/c unit and have it tip slightly otherwise it won't drain properly.
  • Johnchip Johnchip on Jul 25, 2016
    If worried, put some calking around the holes.
  • Gregory Bertolini Gregory Bertolini on Jul 25, 2016
    I have vinyl windows also, rather than drill holes, I have cut two pieces of wood to wedge between the top casing and the top of the lower pane. This keeps the windows from being opened and prevents the AC from falling out.
  • Leslie Leslie on Jul 25, 2016
    I have similar AC units and have had no problems with them. I put them in when it starts to get hot here and take them out in the fall. If the pulled down window is holding the AC in I would not drill holes in the frame. What I do is cut two 1 inch dowels or whatever small wood you have and fit it to the top of the window between the frame and the top of the window that is holding the AC. Cut them a tad longer than that measurement and place them into both corners of that space. You may have to use a hammer to put them in place but it should not be drastic hammering to do so. Just make sure if your top window has a lip at the top that the wood is placed under that lip. They will hold the window down and secure your AC and home. It will be very hard for someone to pull the unit out that way :) If you drill into the vinyl frames water will seep in and eventually rot out your wood window frames. If you are bothered by the black tape around the accordion louvres there is clear duct tape you can purchase. Hope my explanation was ok and good luck.
  • Sophia,M.,McConnery Sophia,M.,McConnery on Jul 25, 2016
    The solution is to seal the screw holes so no moisture gets in.Use a silicone!
  • 861650 861650 on Jul 25, 2016
    My neighbor has a air conditioning unit. She purchased a metal frame that it sits in. In addition, she cleans it once a year and you can watch a "how to" video on "youtube." If, you cannot, or do not want to remove it, there are covers you can purchase as well.
  • Rosemary Kelly Rosemary Kelly on Jul 26, 2016
    You can buy plastic "buttons" or plugs. They snap right in to fiberglass when you decide to take out, say a glass shower door so you don't have screw holes. They come in different sizes. Godwin Plumbing and Heating might have them or any big box store in the plumbing repair dept.
  • Carol Cole Carol Cole on Dec 18, 2017

    I hate the new windows , I have an awful time putting my air conditioner in,

    I wish I had my old wooden windows back.

  • Gina Mia Passarella Gina Mia Passarella on Jun 09, 2018


    I live in a condo- and my central air unit just died.

    My solution for now is an ac unit for my bedroom window, which I am wondering if I HAVE to secure in any way, or could I just let the wi dow be enough?

    I am choosing the bedroom window for safety reasons, because I live on the first floor, but it is raised in the back, so I do not need to worry about someone popping out the unit from that window, as opposed to the living room.

    Thanks for all help!