The size of your room is the very first thing that you want to consider. You can use an Energy Star chart or a climate control unit calculator in order to select a cooling appliance in the appropriate size.
For a room that is approximately 150 to 250 square feet in size, you will have to have an AC unit that is about 6000 BTUs. If your space has adjoining rooms with open doorways or archways, it will be necessary to factor in the area of the connecting room when determining the cooling capacity that is necessary for your space.
If there is shading for the room you will be able to decrease the calculated BTU amount by approximately 10%, but if you want to keep a kitchen space cool you will need to tack on another 400 BTUs.
If two or more people will be occupying the space, it will be necessary to add 600 BTUs for each person to the rating that is required for keeping the room cool.
Before investing in an AC design that has the proper BTU rating for cooling your space, be sure that there is a suitable window for the unit. Take stock of the nearby windows and measure them (making sure to never block a fire escape) and then look for an option that will fit the selecting window opening.
You should recruit some assistance before removing your new air conditioning system from the box. AC units are hard to get a good grip on given their uneven weight and it could be very unfortunate if you dropped your unit.
After you have found someone who can help you out, you can start the installation process by putting up mounting brackets that the manufacturer has supplied. Older units that are very heavy will usually have mounting brackets to support the unit in the window sill and for the outer wall for greater balance.
You should then connect the window unit air conditioner extensions that have been supplied with your purchase. These components will fill the gaps between the unit and the edge of the window sill, so that the air does not leak out. You will be ready to open your window from the bottom and can raise the AC into its position by getting a little assistance from your friend.
Place the air conditioning unit on the sill and the use the extenders to block any gaps. Refer to the AC instructions to ensure that the appliance is properly in place. Many of these units are designed to tilt outwards in order to drain off accumulated condensation.
Last, you should fasten all brackets and lower the window pane down onto the top of your unit. It is often a good idea to lock the upper pane in place so that the air conditioner does not move. For optimal efficiency, use some weatherstripping or caulking to seal all gapes between the window frame and the unit.