At the beginning of the month I go insane and clean my whole apartment. I clean all the bed sheets and curtains. I wash the whole apartment flooring. I then scrub the kitchen, dust the furniture and wash the windows both inside and out. The last job I tackle on my monthly cleaning is my furnace. Every month the furnace filter has to be taken out anyway. This is a great reminder for me to do it. Every new month I get a new furnace filter for my heater. I then take the furnace completely apart and clean it. You would be surprised how much dust gets in a heating system. The blower gets coated in dirt and the furnace works quite sluggishly. I have gotten quite efficient with cleaning the heater too. My vacuum has both blowing in and blowing out capability. For my heating system, blowing the dust out works the best. The vacuum can only reach so far, so pushing the air out of the system is better. The dust flies everywhere and the carpet is a mess, but the heater looks really great. I am able to get all the inner workings super clean. My long hair frequently gets in the heater too. It only lives in there a month before it is gone. You would be surprised by the change in my heater when it is clean too. It runs quieter, faster and I never need to get a heating repair. I think this is all because I am on it with cleaning it monthly.