You can easily upgrade your HVAC system by adding a variable speed air handler. A furnace that has a standard fan operates at all or nothing. With the variable speed air handler the air can circulate at a reduced speed, and runs much more quietly. The advantages of this are:
Cleaner air due to better circulation of pollutants through the filter.
Less fuel used because the air mixes better.
More evenly distributed heat, which will eliminate hot and cold spots.
Overall comfort equality throughout the home.
Furnace add-ons and upgrades should be treated as an investment. After all, they lower your energy costs as well as increase the comfort of your home. The returns you gain by using an air handler will pay off for your entire family.