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Looking at installing a window AC unit for the upcoming summer, I am currently renting and am wondering what the best way to install this unit would be. I’ve looked at using L brackets or laying the unit on a piece of wood and holding it up with a stake. The unit is roughly 35kg just unsure what the best way to install it would be considering the window sill and the brick exterior.
Hi @nathan640,
It sounds like a practical project, although a tricky one as a renter, since you have very limited ability to fix anything permanently to the building. A self-supporting platform is probably your safest and most reliable option. A simple frame made from 70 by 35 millimetre H3 treated pine with a plywood top will comfortably carry a 35kg unit. If you paint the plywood top and the bottoms of the feet that touch the ground, you will slow any moisture-related deterioration and keep everything stable through summer. This approach avoids drilling into the brickwork and still gives you a solid, level base.
I have had a similar situation in my rental where I installed a window box. In my case, the house was old, so with the landlord’s permission, I could fix timber brackets into the weatherboards and studs from outside. That gave me a wall-supported platform. Without that option, a freestanding stand is likely the best option. Once you have the platform in place, check whether the air conditioner fills the entire width of the window opening. If it is narrower, you can use simple timber trim pieces to pack out the gaps so the sash can close down onto the top of the unit neatly. After that, think carefully about waterproofing. Any rain that hits the top of the unit can track under the window plane and into the room, so sealing the joint is important. Bitumen-backed flashing tape works well, although be aware that certain tapes can leave residue on some window frames when removed.
Finally, before you go too far, it is always worth contacting your landlord to explain your plan. They may be comfortable with you drilling into the brickwork if you agree to patch the holes later.
Please let me know if you have any questions.
Mitchell
Hi @nathan640,
I agree with @MitchellMc and have some additional suggestions regarding gaps and weatherproofing.
On the inside I propose a timber frame that slides into the window frame and sits flush with the front of the aircon.
Cheers
