New York's Cooperative and Condominium Community

Habitat Magazine Insider Guide



Rules for Keeping Cool

Summer is coming – and with it, A/C concerns.

A poorly installed air-conditioner can pose as much danger to pedestrians as loose bricks on a building’s facade, so property managers and boards must be certain that all units at their buildings are adequately secured.

The window and frame in which the unit will be mounted should be secure and in good condition. The unit should be braced from underneath with metal brackets, mounting rails, or similar supports, or firmly fastened from inside with supporting angles. The metal brackets and angles should be attached to the exterior of the building and be strong enough to support the size and weight of the unit.

Anything used to adjust the position of the air-conditioner, such as shims, should be independently secured to prevent shifting caused by vibration, wind, or ice. The air-conditioner should remain in place when the window is opened, or secured so that the window cannot be opened accidentally. Bricks, wooden blocks, or phone books should never be wedged between an air-conditioner and the windowsill. Items such as flowerpots, satellite dishes, and bird feeders should not be placed on top of the unit.

The manager should create installation guidelines and procedures and make sure all residents comply. For example, you can have a rule that the units must be installed only by someone deemed “qualified,” such as the superintendent, a maintenance person, a technician from the store that provided the unit, or a contractor.  Boards and property managers must work together to prepare building residents for a change in the rules. Now is the time to start sending out notices explaining why installation procedures have to change.

If a poorly installed unit falls and injures or kills someone, the corporation will certainly be held liable. Having rules and guidelines in place will go a long way towards preventing a tragedy.


Air-Conditioner Installation at a Glance
Always follow the manufacturer’s instructions

Secure Installation

Make sure the unit is installed securely. It can be supported from inside the unit or from below outside, but any supporting brackets or rails should be independently fastened to the building envelope and strong enough to support the unit and prevent shifting due to vibration or weather.

Window Treatment

Install the A/C so that it won’t move when the window is opened, or secure it so that the window won’t be opened accidentally.


Tilt the A/C so that it can drain properly, but be careful not to tilt it too much!

For more information, check out the DOB’s A/C Installation Tips:

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