Quote Originally Posted by monte55 View Post
I am in the HVAC business............I have a customer that owns three houses within one block (not a great neighborhood). In one house......thieves stole the central air conditioner while the house was unrented, and on another of their properties, thieves went in last fall and stripped the central air conditioner of copper/aluminum..........and even destroyed/stripped the furnace of the A coil, ripped out copper water lines etc. I have installed new heat/cool systems in each of these properties. To deter thieves, I have built a cage/fence with a lockable gate around each A/C unit. Here are some pics of the cage/fence with lockable gate that some of you may be interested in promoting and selling in your area. Just remember to take measurements of where the A/C unit will be and keep in mind to leave space so the gate can be opened for servicing. The posts on this are 1" square tube (14 gauge) and capped with 1 " square plastic plugs, the pickets are 3/8 " solid round, horizontal are 1" x 1/2" C channel. The extra length of the posts allow for 12 to 15 " to be set in concrete (if the customer wishes). I charged $285 for this one.....................they picked up, will install and paint it themselves.
Also you may interest them in security bars for windows but be sure to check with local codes as to whether it has to be able to be opened in case of fire. The security bars can be built the same as the A/C cage (or fancier, of course).
Twenty plus years ago I made some cages out of 7/8" succor rod for a/c units in Dallas. The response was so positive I thought about producing them until I looked in the local yellow pages. There were guys out that already that was their specialty.

Besides that, most of the time those things are for landlords and they have no morals when it comes to contractors. They are notorious for taking your idea and shopping it around for the lowest price. I've been on both sides of that conversation btw.