Before Purchase/Installation
• Calculate the size of room to be cooled, so that you buy an a/c with the proper capacity (BTU).
• Obtain authorization for installation from building management, if it is needed.
• Make sure that electrical service is adequate.
• Make sure that the window and window frame are in good condition.

INSTALLATION GUIDELINES
• Follow the manufacturer’s instructions included with the unit.
• Make sure the unit is installed securely. Support the A/C unit from underneath or firmly fasten it from inside with angles. Metal brackets, mounting rails, etc. may be used for a safe installation.
• Supporting metal brackets, interior angles, etc. should be structurally fastened to the building envelope and are to be strong enough for the size and weight of the A/C unit.
• Objects utilized to adjust the position (for example, shims) of the A/C unit must have an independent source of fastening or attachment.
• Secure leveling objects in order to prevent movement and shifting due to vibration from the A/C unit and wind and weather conditions.
• Install the A/C so that it remains in place when the window is opened and or affix it so that the window cannot be opened accidentally.
• Tilt the unit slightly to provide water drainage; however, do not over tilt.

WHAT TO AVOID
• DO NOT USE loose objects, such as wood blocking, to support the leveling of an A/C unit.
• DO NOT USE bricks, telephone books, gypsum board or cans for leveling under the A/C unit.
• DO NOT BLOCK fire escape windows or any other exit with an A/C unit.
• DO NOT PLACE anything (TV antennae, satellite dishes, plants, etc.) on top of an A/C unit.

Maintenance
It’s important to periodically check on the position of the A/C and the condition of the window
frame to make sure that the A/C remains supported and secure.

Information here was provided directly from NYC Government website