If you have a residential and commercial HVAC system that is 10-15 years old

If you have a residential and commercial HVAC system that is 10-15 years old then you might have to buy a brand new energy-efficient HVAC unit if you want to cut down on your power cost. But, if your furnace and air conditioning unit is not more than 5 years old then there are some steps that you can follow to get the most out of your residential and commercial HVAC system and cut down on your utility bills