The local contractor I work with does a lot of home services work, especially in the summer and winter months when everyone seems to be having a problem with their HVAC system. I guess a lot of people find out when they try to run their systems that there is a problem with them, and so they call us frantically looking for help so they can be comfortable again. I think many people are not good at keeping their HVAC system clean and they end up causing harm to the system by running it when it is dirty. I’ve seen some HEPA filters with an inch of dust buildup on it and it is truly amazing that the HVAC system is able to pull any air in at all. I’ve known of several people, mostly younger folks, who didn’t even know that there was a filter to clean. I guess they thought that the dust just kept blowing around the flat or something like that, and didn’t even know or think about the system having filtration on it. The new smart thermostats remind you when it is time to clean the filter and this helps a lot for people like me who tend to forget about doing it. Sometimes I didn’t even realize that three months had already gone by since the last time it was cleaned. So this is why we have to do a lot of service calls at the beginning of the hot and cold months. At least it keeps us busy for a while during those intense weather months.