Energy efficiency can be improved even more in central heating systems by introducing zoned heating. This allows a more granular application of heat, similar to non-central heating systems. Zones are controlled by multiple thermostats. In water heating systems the thermostats control zone valves, and in forced air systems they control zone dampers inside the vents which selectively block the flow of air. In this case, the control system is very critical to maintaining a proper temperature.
Two weeks go by and no phone call from HVAC Service regarding install date, or any update at all. I call them to check in to see if they have put me on the schedule and when I can expect to have the AC installed. You can tell by the discussion I had with the lady on the phone that they completely forgot about me and have not scheduled anything. She says she needs to get in contact with the owner because she has no idea on the availability of the crane. I was told that she would call me back by the end of the day with an update. Surprise, surprise, no phone call.
Since most states and municipalities don’t license air duct cleaners, you need to check their professional credentials instead, such as NADCA membership. EPA recommends all duct cleaners follow NADCA standards. Member companies must keep at least one technician on staff who has passed a NADCA test. “They have to pass rigorous testing to earn the certificate, and our code of ethics is very important,” Vinick says.