There are many air cleaners available in the market. Specific to efficiently removing indoor airborne allergens are HEPA air purifiers which incorporate ionizers.

HEPA (high efficiency particulate arrestance) filters are capable of removing 99.97% of particulates as small as 0.3 microns.  The specifications have become an industry standard in most critical medical and hi-tech applications. Trapped particles in the filter are never flushed out of the filter, the efficiency of the 99.97% never decreases, and the HEPA filtration process is purely mechanical and produces no by-products. Once the air is drawn into the device with a fan, the particles are filtered, and the cleansed air is then release back into the room. The filters are replaceable and can last for years. They are most effective in capturing airborne allergens, but are rather noisy and do not eliminate chemical fumes, gases, smoke, or odors.

Ionic air purifiers, also called air ionizers, work by ionizing or neutralizing air particulates. When switched on, voltage runs through a series of built-in needles, creating electrons, that when discharged into the air, they attach to air molecules and form ions. These negative ions are released into the room and attach to dust, pollen, cigarette smoke and pet dander to form larger particles, which are easier to capture into the air cleaner’s filters. The process will require regular vacuuming and dusting to finish the job. They are very quiet compared to other air purifier. However, they do not get rid of odors, and cannot kill germs.

Products

You can easily purchase an air cleaner that incorporates the technologies of the HEPA filtration system and ionic air purifiers. But remember, to optimize the efficiency of these air purifiers, make sure that you replace the filters regularly.

Here are the more popular products:

Surround Air Intelli-Pro HEPA UV Ionic Air Purifier
Other than having a highly efficient HEPA filter and ionizer, the Intelli-Pro also has built-in germicidal ultraviolet (UV) lamps and an activated carbon filter. The device is practically complete and can capture virtually any pollutant in the house. The unique feature of the Intelli-Pro is a sensor that monitors the air quality inside the room as well as the performance of its internal components. The sensor also tells you when to replace the filters. Each unit covers up to 650 square feet and would cost around $300 each.

Surround Air XJ-3000C Ionic HEPA UV Home Air Purifier
The combined technology found in this model from Surround Air is similar to the Intelli-Pro, but it also has a programmable ozone air purifier for odors. Each unit covers up to 500 square feet and would cost less than $200 each.

Blueair 501 / 402 / 201 / 205e Air Purifiers
Blueair features electrostatic technologies combined with a HEPASilent™ filter technology for the cleanest air and quiet operation. To minimize drafts, Blueair disperses clean air on three sides through the SurroundAir.™ system. This is the best choice for those who want a quiet machine for use in the bedroom or office. The units look good with a steel surface and the compact design blends in discreetly with practically any decor. The Blueair 501 is enough to clean a large-sized room, up to 550 square feet and would cost around $500. The Blueair 402 model is smaller and can clean up to 365 square feet. It would cost less at around $400. The 201 and 205e models have similar air purifying features, although they are for smaller rooms, up to 200 square feet in size. You could get them for around $300 each.