Air filters are an important, but often overlooked, part of the HVAC system. The primary purpose of a furnace or a/c filter is to trap and remove dust, dirt, hair, fur, fibers, bacteria, pollen, mold, etc. from the air in your house, and to protect the HVAC system. Without a filter, these impurities will compromise the efficiency and longevity of your heating and air conditioning equipment.

Furnace and A/C filters vary considerably in quality. The MERV rating is used to measure the ability of the filter to remove pollutants from the air. The higher the MERV rating, the better job the filter does in cleaning the air. Furnace and air conditioning filters are available at various price levels. It is usually true that the higher the cost of a filter, the better for your indoor air quality and your HVAC system.

Let’s now look at the different levels of filters in terms of price and their effectiveness.

$1.50 filter (MERV 1-4)

This essentially protects your small child or animal from being sucked into the furnace! Jokes aside, there isn’t much else that this furnace and air conditioning filter does.

These are usually flat filters with less surface area with which to clean the air. They also need to be changed more frequently than higher-quality filters.

$3 filter (MERV 5-8)

HVAC filters at this level provide basic filtration for your heating or air conditioning system. They can trap dander, pet hair, and mold to help keep the air free of these highly allergenic particles.

$15 – $20 filter (MERV 9-12)

At this MERV rating, filters are able to trap dust particles and are perfect for homes where there are people with allergies, asthma, and other respiratory conditions.

Such filters are generally pleated. Pleats give more surface area for the air to move through and get cleaned.

These are the best filters for your money. They keep the air clean, protect the HVAC system, and don’t need system modifications for their installation.

$45 filter

At this price range, you can get electrostatic filters. These furnace and air conditioner filters use static electricity to clean the air.

An electrostatic filter is made of multiple layers of mesh or vented metal. These are washable filters. In essence, you don’t have to replace them at all. Simply wash them clean and reuse. The downside to such a filter is that it restricts the flow of air.

These aren’t the best filters for homes because they can damage your equipment. The price of this filter is high because you don’t have to replace filters.

Such a filter is best for a home where the only concern is to protect the HVAC equipment and nothing else.

IQ Air filter (MERV 16)

This is the Rolls Royce of filters!

These are outstanding filters. If you want the air inside your home to be as clean as possible, this is the filter you want for your furnace and air conditioner.

Before we install the filter, we use a particle scanner to measure the quality of the air. After installation, we test the air again. The change is generally dramatic!

When we installed the IQ filter in the home of one of our Redwood City clients, they said that they could actually “taste the clean air”!

For these filters to be efficient, the furnace or air conditioning fan has to run continuously. The IQ filter will last 3 years or 18 months with a fan running continuously.

They cost between $350 and $400 for a set of 4 filters and cost between $2600-$3200 to install. We said it was the Rolls Royce of filters, didn’t we?

Have questions about filters, furnaces, ducts or air conditioners? Call Redwood City’s best HVAC contractor. RC Mechanical is an owner-operated Redwood City business and has provided expert furnace and air conditioning repair and installation to the Bay Area with integrity for over 20 years. Call us today at (650) 575-3915. Homeowners in Redwood City and throughout the Bay Area count on us for all their heating and air conditioning needs.