TH Oliver recommends the following media filters by

 
The Aprilaire® Media Air Cleaner is a silent, low-maintenance, inexpensive air filtration system. It utilizes a simple, remarkably effective HEPA-type filtering media that actually improves its particulate-capturing capability the longer it is used.For particles larger than five microns, efficiency reaches 99%. Even the smallest particles, as small as one micron, can be filtered out at 95% effectiveness. The high-density filter unit is attached to your existing heating or cooling system, where it captures pollutants from conditioned air before it is distributed to the rooms of your home.
Two models of Aprilaire Media Air Cleaners are available, depending on your furnace type. Both models provide the same superior performance. Since these models have no moving parts, they’re virtually maintenance free and come with a lifetime limited warranty












.Model 2200 is easily adaptable to upflow or horizontal duct configurations






Model 2400 is compact, great for use with today's shorter furnaces in platform or closet installations.

  • Never less than 99% efficient on pollen and spores.
  • 60% average efficiency on all particles.
  • Provides allergy relief. Ask your doctor.
  • Air Cleaner media lasts one to two years.
  • Protects heating and cooling equipment.
  • Absolutely silent operation.
  • Uses no electricity.
  • Lifetime limited warranty.