The A/C unit in storage I'm not crazy about. If you have two units go down. Now one has temp units and the other you have to end up doing what I said and that's communicating. People want to know you care. Let your tenants you are doing the best you can and that you care about their situation. Give them an estimated time for the repairs and honor it. Paying a couple of hundred dollars to move units and then a couple of hundred to retrieve them later is a big headache and costly. Plus, that could take a day or so to coordinate and what if they break a window or something? I would use this time to get with one of my A/C guys and fix their problem. The neat thing is in my city HVAC supply houses are everywhere I can't recall a time I had to wait for part. Typical things that go wrong are the relay, fan motor, capacitors, and thermostat. All are in stock. I like to be proactive and service units once a year in the spring right before heavy use. Filter change, condenser cleaning, and a good look-over of the inside unit. Just this alone can catch or prevent most problems. I'm not saying what the others are saying is wrong I'm sharing how I handle things with my properties.