I have a brand modern central heating as well as air conditioning idea plus it is running so well. I just need to keep the HEPA filter scrub plus it will do the rest. I did have the drain tube under the air handler back up a couple of times plus leak onto our lavatory floor however the HVAC techs came out plus fixed it immediately. They told myself and others if it happens again to poor bleach down the inlet opening that they installed plus it should repair the problem in a few hours. It’s just that drain pan that fills up under the a/c when the tube is obstructed so it is an easy repair if I just keep the tube scrub plus free of mildew plus mold buildup. I am going to pour bleach in the tube every month or so to keep the tube scrub plus that should solve the leaking problem for good. I’m going to let the HVAC techs do the ductwork cleaning when the time comes because that is just too much for me, given that I am highly allergic to dust plus pollen. I have enough on our hands with the songwriting plus music editing I am doing for our band. I am pretty glad with the air quality in our flat plus have the HVAC crew to thank for teaching myself and others how to keep it running smoothly by keeping everything tuned up plus scrub in the unit. I have a service idea with the HVAC company so I am covered for years.