I am trying to install a 5000 BTU window A/C in two room windows as shown here.
Is the A/C rests on stool or the still?
Also can the stool/Sill support 45 Lbs weight of the unit? or do i i need a L clamp on the siding outside? I don't want to use the deck for support, as it is junk and will be disassembled soon. Thanks

 

I've installed a number of window units of that size in wood windows without any external bracket and not had any problems. I have had to build up the sill in some cases so the unit would clear the frame for the screen/storm.

What do the install instructions for the unit recommend?

 

Thanks. I am getting the unit delivered tomorrow. Will research the instructions

 

Window air conditioners generally have a flange on the top edge of the box that catches the bottom corner of the opened window sash. The box also usually has an indentation that sits over the lip of the stool, and screws can be fastened to secure it... then you slide the AC in. As mentioned, you sometimes need a wood filler to sit on the sloped sill to create a flat spot in the event that it wont sit on the stool and wants to slide down the sill.

Generally the AC gets pushed all the way out, not barely out... like in your photo. Your instructions should make this clear. Generally the box is installed first, then the AC unit is slid into it.


The AC brackets / L brackets are great because they help take the weight off of the window sash. For instance, you would never want to put a huge AC like that on a vinyl window without the brackets and without a filler underneath it. Your wood window is probably ok, but I would use brackets. They are adjustable and also help hold the AC unit at the right angle so the condensation can drain.

 

I was in the same situation like you. I got brand new vinyl windows for my house and did not want the AC Window Units to rest on top of my windows. I agree with XSleeper that it is probably NOT a good idea to rest these units on vinyl windows.

I have installed 3 AC Window Units (8K BTU). Two of them are for horizontal sliding windows and one of them is for a vertical sliding window, similar to yours. The unit for the vertical sliding window is for my sister's house. It is much easier to install since I did not have to cut an extra board to cover the opening, like for a horizontal window.

I read that you don't want to mount to the sidings but regardless, I will share with you what I did for my setup (by building an exterior shelf):

Cut this in half (25 in. Twin Track Upright): Rubbermaid 25 in. Twin Track Upright-FG4B8700WHT - The Home Depot

Find the studs with a stud finder and mount from the exterior of the house. Use 1.5-2 inches screws. Mount not to the center of the window but more to either the right or left side of the window. They should be about 15-20 inches apart and it will depends on the width of your AC Window Unit.

I bought two of these: Rubbermaid 11-1/2 in. White Twin Track Shelf Bracket-FG4C0502WHT - The Home Depot

Brackets can hold up to 200 lbs.

Put these brackets on and a thick board across them. Use 2x4 to elevate accordingly, both on the board and the stool. The back of the AC Window Unit needs to be a bit lower so that the condensation can drain properly. The 2x4 stacks on the board should be perpendicular to the board, in case you bump the AC Window Unit, the stacks does not tip over and slide your AC Window Unit right how of the window.

If you elevate correctly, the AC Window Unit will not sit on your window but instead, on the 2x4 stacks. I only use one 2x4 for the stool and three 2x4 for the stacks. I have two stacks for left and right side of the AC Window Unit.

When fall or winter comes around, you can take the entire thing down, including the brackets, and store them. I have done this setup for the last 3 years. I setup last week and ready for summer. It took only 10 minutes for each unit to pull out from storage and setup.

 

Buy one of these to do it right and not cause any damage to the home.
Parts & Accessories - Air Conditioners - Air Conditioners & Coolers - The Home Depot

 

WRDIY - I was thinking the same- using angle brackets. Do you have a picture? Thanks

 

I bought one of those from HD. I am not a big fan of them. It is not as sturdy as it looks. It may look wide (and platform like) in the picture but it is less than 5 inches wide. Either way, the AC Window Unit would still rest on the vinyl window. Final straw, I returned it because it requires drilling and screwing into the stool.

This was the one that I bought:
http://www.homedepot.com/p/AC-Safe-U...-160/100123126

However, in your same link, this may work:
http://www.homedepot.com/p/AC-Safe-N...TN-2/206510455

But not for my case because I don't want the AC Window Unit to sit on my window frame.

SethRamesh, notice, I screwed "L" brackets into the 2x4, not the stool, for stability for the interior. I could have used another 2x4 instead. Anyway, it is not resting on the window.

https://www.dropbox.com/sh/whgmntl4a...VyzelK-ta?dl=0

Also, if you will be using angle brackets that I am thinking you are referring to, you will have to unscrew them if you want to take them down each season. Those brackets that I provided above, you just need to unlatch them and store them. The only thing remains intact would be the rails. If you paint them the same color with your sidings, they would be camouflage into the background.

 

I have tools so I build up the stool to at least the height of the track and then lay plywood through the window opening. Then make a wedge to support the plywood from the outer edge of the stool. Add some cleats to the plywood to hold the lower channel steel of the A/C case, both inside and out.

Then, in the case of a sliding window I add 1x4 or 1x6 common with blocking to close the side opening and add plywood to the inside. Add foamboard insulation and then another piece of plywood outside. This securely locks the unit in place and places no undue weight on the window tracks.

For a vertical window I would bring the sash down tight on a piece of foam weatherstripping and then cut blocks to fit between the top of the sash and the top of the window to lock it into place.

May not be the neatest install but it is secure.

 

Would you have a picture Furd? I am interested to see it visually. Thanks

 

Sorry, but no. Too much clutter inside and too many blackberries outside to even attempt a picture. If this unit didn't have a remote control I couldn't use it.

 

Ok, thanks. I had to clean up my room too before I took the picture of my AC Unit (posted above).

 

Here is a solution I posted in another thread but it does require basic carpentry tools and skill. Other solutions are ready made and probably easier.

 

WRDIY - Thanks for the drop box picture. Looks very solid. BTW, is DANBY good? I received a Frigidaire, but was not working, so returned it back

is the inside 2X4 nailed to the studs?

 

First, I love Danby because you won't be able to get the bang for the buck with any other brand. I bought the 8K BTU from Costco for $189. I returned 1 out of 4 because it was making noises. It has been 3 years and still running quietly. We turn it on at night because there is no point of turning on the central AC and waste all of that electricity. The AC Window Unit uses so much less electricity. We turn on the central AC only when we have guests or when there is a need to cool more than 2 rooms. My central AC pulls between 30 to 40 amps while each of these AC Window Units is pulling only 5 amps. My central AC still can cool the entire house quicker and faster but the AC Window Unit is so cost effective.

Second, I did not nail or screw any 2x4 to anything. They are only for elevation purposes. The only thing that I screwed are those small "L" brackets to the 2x4 that you see in the picture for stabilization, as mentioned in the previous post. I also screwed the twin rails to the stud of the wall. That is it for screwing. Again, when winter comes around, I take everything down and store them for next year, including the 2x4.

Ray, thanks for sharing.

 

WRDIY. Goit it. Thanks for sharing. Using Twin Track Rubbermaid bracket is a very smart idea.
How did you find the studs beneath siding. Does the stud finder works on the sidings?

 

Good question and forgot to share with you how I found the stud through my stucco wall. No, the normal stud finder will not be able to find your stud from the exterior (stucco). I also have a very power Franklin Stud Finder that I bought from Costco. Even with that, I wasn't able to find the stud. http://precisionstudsensors.com/products/profinder_5000.php

I used this to find the drywall screw from the inside (5 stars):
C.H. Hanson Magnetic Stud Finder-03040 - The Home Depot

Since you know the drywall screw has to go into a stud, this magnet stud finder will find a drywall screw. Once you find it, you put a small nail above it into the drywall and tie a kite line to this nail. Hang the kite line out of the window with a pendulum (tie something like several washers) on the other end. With that line going down, I drill based off of that kite line.

I predrill with a masonry bit and then put in exterior screws (1.5-2 inches).

 

WRDIY Fantastic. I have the same stud finder. Will try.