Does setting the central ac fan to on to clean the air?

Answer 1

Yes it does, providing there is an air filter in place. You will also even out the temperatures in different parts of the home. This is where you can do a better job of cleaning the air and removing dust and particulate by choosing a higher efficiency filter. A "pleated" filter will increase the removal of particulate without adding increased restriction to the furnace/ ac system. Many people make the mistake however, of installing an electrostatic/ washable filter of the same physical size as the original filter they removed. The problem they create is that while the electrostatic filter is more efficient in that some will filter out mold spores and cigarette smoke, etc, they increase the temperature rise in the case of a furnace, or the temp. drop in the case of an a/c system. In the case of a furnace this will increase the risk of errant safety limit trips and furnace operation above the temperature rise specified by the manufacturer. In the case of a/c systems, the increased restriction may cause icing of the a/c coil. The furnace nameplate should be checked for the listed temperature rise. Measure the temperature of the air entering the unit and leaving the unit. After 10-15 minutes of operation the calculated "temperature rise" should fall within the range listed on the rating plate. If going to an electrostatic filter, have a good HVAC contractor install a filter rack diagonally in the return air. This allows you to install a larger surface area filter that will reduce the static pressure drop of the filter in the system. One option I have installed for many customers is called a "filter enhancer". It acts as the electrostatic filter does, by charging the air passing over the installed probe with electricity. The charged particles are then caught by the pleated filter. This type of setup costs lots less than electronic air filters and has far less in the way of maintenance issues. It works on the principle of electropheresis.(I may have not spelled it right) The enhancer I install is the airscreen 6000 manufatured by Cimatec. Good luck! lc