My central heating in addition to air conditioning method unit had broke down recently, and the reason it broke down was all our fault for being careless and lazy, I found out from the heat and air conditioning system specialist the reason our central heat and air conditioning system unit broke down was because I did not change the air filter as often as I should. It caused the heating in addition to A/C unit to overwork itself and I did not recognize this was happening, and but now I do; however, the certified heat and air conditioning system specialist from the local heating in addition to air conditioning supplier told me that I should in future change the air filter of the central heating in addition to A/C unit once a month no matter what! Even if the air filter appears to not need increasing, still change it. It is simply better to be safe than sorry. The heating and cooling specialist also told me that I may want to look into getting HEPA air filters for our central heat and air conditioning system unit. Because HEPA air filters not only last longer, but they can also help have better air quality in the home! However, they are not as strong as a whole home air purification method but maybe the equal of having a few portable air cleaners instead. That is the benefit of HEPA air filters I was told. Nonetheless, I will definitely end up now increasing our air filters of the central heating in addition to the air conditioning method once a month and I will look into buying HEPA air filters. They may cost a little more I was told, but in the long run it kind of saves money as well.