Product Overview
One or two filter changes a year.
Not six.
Many basic furnace filters are replaced every few months. The Camfil Dual 9 is built to stay in service much longer while maintaining its MERV 9 efficiency.
It sits in the same slot your furnace and central air conditioner share, so it works all year, not just in winter.
Will this replace the filter you have?
You don't need to buy the same brand again. The brand printed on your old filter does not matter. The size does.
Read the edge of the filter you are holding. If it says 16x25x4, you are in the right place. Many filters also print their exact size, and that is the number that really counts.
Better still, measure it. Compare your three measurements to ours. If they match, this filter goes in, whatever brand you have now.
Our exact size
15 3/8 x 24 3/8 x 3 3/4 in
(39.1 x 61.9 x 9.5 cm)
Measure your filter and compare. If the three numbers match, it fits.
One thing to watch: some filters sold as a 16x25x4 are deeper than this. If yours measures more than 3 3/4 in deep, it is a different filter. Call (888) 315-0105 and we will sort it out in two minutes.
It also drops straight into the same slot as any Camfil 16x25x4 you may be running today, in MERV 8, MERV 11 or MERV 13.
Who this filter is for
A standard MERV 8 is usually replaced about six times a year. The Dual 9 is built for one or two. Fewer boxes to buy, fewer trips to the basement.
Yes, a Dual 9 costs more than a basic filter. But you use two a year, not six. Check the prices on this site and add up a full year of each.
Sometimes the ventilation unit is simply hard to get to. A rooftop air handler, a unit in a ceiling, a commercial building or an apartment block. Every filter change is a climb, so two a year instead of six is four climbs you skip.
What it catches
MERV is a rating that tells you how well a filter captures airborne particles. A higher number means finer filtration.
A MERV 9 helps capture:
- House dust and lint
- Pet hair and dander
- Pollen
- Mould spores
- Dust mite debris
- Dust from sanding and home projects
Most homes use a MERV 8 filter. A MERV 9 provides a little more filtration while still being suitable for many residential HVAC systems.
Straight answer: it is not designed for smoke or the very smallest airborne particles. Those require higher efficiency filtration that should be properly matched to your HVAC system.
If you want finer filtration in the same slot, the Camfil 16x25x4 MERV 13 is the step up. It captures more, and it fills up sooner, so you replace it more often.
Why it lasts
Two layers, not one. The white upstream layer is designed to capture larger particles. The green downstream layer captures finer particles.
The media is pleated back and forth to create more surface area inside the same filter frame. Camfil says the Dual 9 can hold four times more dust than general commercial grade pleated filters before reaching capacity.
Look at the support grid. A welded wire grid behind the pleats helps keep them open and evenly spaced throughout the life of the filter. The grid is also treated to resist corrosion.
The Dual 9 uses a distinctive gold coloured support grid behind the filter media.
Keeping the pleats properly spaced helps air continue moving through the filter as dust builds up.
The part nobody tells you
Many low cost synthetic filters rely partly on an electrostatic charge to capture particles. That charge can weaken over time and filtration efficiency can drop.
The Dual 9 uses mechanical particle capture instead of relying on an electrostatic charge.
That is where the MERV 9A rating matters. The filter is tested after the media has been conditioned to see how well it continues to perform after any temporary electrostatic effect has been removed.
The Dual 9 is rated MERV 9 and MERV 9A, which means it is designed to maintain its rated filtration efficiency throughout its service life.
Tested, and the numbers are published. Camfil tests to ASHRAE Standard 52.2 and publishes both a MERV and a MERV-A rating. If another filter gives you a number, ask which standard it comes from.
It should get dirty
Camfil guarantees the Dual 9 for 9 months in heavy load industrial applications and 12 months in commercial duty applications. Homes are different, so actual residential life depends on your HVAC use and how much dust is in your air.
Expect it to look dirty when you remove it. That means the filter has been collecting particles instead of letting them continue through your HVAC system.
An arrow marked AIR FLOW is printed on the filter frame. Slide the new one in with that arrow pointing toward the furnace, in the direction the air travels.
What fills it up faster
Two homes can use the same filter and get very different results. It depends on how much dust is in the air and how much air moves through the filter.
Your filter may fill up faster if you have:
- Dogs or cats
- A busy street, gravel road or construction nearby
- More dust and particles in the surrounding air
- Sanding, woodworking or home renovations
- Other activities around the house that create dust
A cleaner home with fewer sources of dust may get considerably more life from the same filter.
If your thermostat fan is set to ON instead of AUTO, air moves through the filter much more often, so it can fill up sooner. That simply means more air is being filtered.
Easier on your furnace and A/C
The Dual 9 is designed to maintain good airflow as it loads with dust. Camfil reports energy savings of up to 25% per filter opening compared with lower cost pleated filters.
In winter, a heavily loaded filter can reduce the amount of warm air moving through your system and into your rooms.
In summer, restricted airflow can also make your air conditioner work harder. In some systems, very low airflow can even contribute to the indoor coil icing up.
Camfil also reports that improved filtration can reduce the need for coil and HVAC system cleaning by 25% to 50% compared with lower efficiency MERV 7 and MERV 8 filters.
Why Camfil
Camfil is a Swedish company, founded in 1963, with 30 manufacturing sites around the world. It supplies filters for homes, commercial buildings, hospitals, laboratories and many other demanding environments.
The Dual 9 was tested for several years under real operating conditions before Camfil introduced its long life performance guarantee.
Details
- Sold as: 16x25x4
- Exact size: 15 3/8 x 24 3/8 x 3 3/4 in (39.1 x 61.9 x 9.5 cm)
- Part number: 406332004
- Model: Camfil 30/30 Dual 9
- Rating: MERV 9 and MERV 9A
- Use: furnaces and central air conditioning systems with ducted airflow
- Media: dual layered blended polyester
- Support: welded wire grid
- Frame: moisture resistant beverage board
- Colour: white upstream layer, green downstream layer
- In the box: six filters
Warranty and returns
Covered by Camfil against manufacturing defects for 1 year.
You can return your order within 35 days if the filters come back unused and in their original packaging. Return shipping is paid by the buyer. One used or damaged filter voids the return of the whole box, so open only what you need.
A Canadian company 
We are Canadian, and we answer our own phone.
Free shipping in most of Canada. Not available to Yukon, Northwest Territories, Nunavut, or Newfoundland and Labrador.
Camfil orders placed before 11 a.m. Eastern on a business day usually ship the same day.
Still not sure? Not convinced? Call us or send us a note. We would rather answer a question now than process a return later.
Need another size in this series? See every format on the Camfil Dual 9 page. Product photos are for illustration and may differ slightly from what you receive.
