When I was in need of troubleshooting a problem with my AC system, I called to request a service call. The technician came out and worked to deduce the problem was a faulty accumulator. He described the process of troubleshooting thoroughly without me prompting. After the work was done, I asked a question about possible modifications to direct more are to other parts of the house. The technician could have told me what he thought knowing he looked at the system already. He decided to get a ladder out and check on the duct work to see what could be done to meet what I was looking for. I was impressed by that. Not only did he explain how the retrofit would work he also advised that there is a cheaper option of using dampeners or a more expensive multi-zone modification to the system.