A whole house air purifier could be a good deal

If you have a central heating and/or cooling unit that circulates air throughout the house then installing a whole house air cleaner is worth considering.
No lugging around of a portable air purifier from room to room, or purchasing of multiple air cleaners, and silent operation of the whole house air purifier are some of the benefits that come to mind.

And as long as you are aware of some limitations to whole house air cleaners, then the purchase of a whole house air purifier is definitely a better deal than buying separate air purifiers for each room in the house.

Whole house air purifiers clean the air as it is returned to the central air conditioning and/or heating unit. Most whole house air cleaner rely on the central unit to move the air, and therefore:

• as a HEPA type filter restricts the airflow too much, only particles larger than 1 to 1.5 microns can be removed, so the whole house air purifier will fail to catch many allergen, most bacteria, and no viruses
• the whole house cleaner only works when the central unit is turned on, resulting in a higher electricity bill.

The good news is that there are some whole house HEPA air purifiers that create their own airflow, and that can be retrofitted to the existing central air or heating system. You will need space in your furnace room though, as these units can be over 4 feet high.  A good example of these whole house HEPA air cleaners is the Amaircare 5000V.

Alternatives to using a filter

One option is to use ultra violet light (UV), which has been around for almost a 100 years now. The UV rays break through the outer membrane of microbes, destroying viruses, bacteria, and allergen such as molds, mildew, and fungi.

Another type of whole house cleaner releases photolic ozone and hydroxyl radicals, and has the same effect as a UV system.

As neither system filters out the larger particles, such as pollen and pet dander, adding an electrostatic furnace filter is a good idea.

As the air flows though the electrostatic filter, it gets charged and attracts the particles . Unlike an ionizer the particles themselves are not charged.
Some of the filters on the market are not replaceable and have to be cleaned every other month or so.
Benefits of an electrostatic filter:

• An efficient filter can reduce your particulate levels and therefore air pollution by up to 50%.
• You will be protecting your furnace and air conditioner, and the incoming pollution will be reduced.