Camfil Dual 9 Long-Life Furnace and A/C Filter (MERV 9)

Two filter changes a year.
Not six.

The filter in your furnace right now is probably worn out after eight weeks. This one keeps working for months, winter and summer.

Furnace and air conditioner

Your furnace and your central air conditioner use the same filter slot. One filter does both jobs.

So it is working every month of the year, not just in winter. Most people forget that, and it is why cheap filters run out so fast.

What it catches

MERV is just a score for how much a filter holds back. Higher score, more caught.

A MERV 9 pulls out:

• House dust and lint
• Pet hair and the skin flakes pets leave behind
• Pollen
• Mould spores
• Dust mite droppings
• Dust from sanding and home projects

Most homes run a MERV 8. A MERV 9 catches all of that, plus the smaller bits a MERV 8 lets slip by.

Straight answer: it will not stop smoke or the very smallest bits. Those need a much tighter filter, and tighter filters make your system work harder.

Why it lasts

Two layers, not one. The white side catches the big stuff. The green side behind it catches the fine stuff.

The material is pleated, folded back and forth like an accordion, so a lot more filter fits into the same slot. Together the two layers hold four times more dust than a regular pleated filter before they fill up.

Look at the wire. Behind the pleats sits a criss-cross wire mesh, welded every inch, that holds them open and evenly spaced for the whole life of the filter. It is treated so it will not rust.

It is also gold, not the plain silver you see on every other pleated filter. That gold mesh is the easiest way to recognize a real Dual 9 at a glance.

Because the pleats never sag, air keeps flowing through instead of pushing against a collapsed filter.

The part nobody tells you

Most cheap filters work with static, the same way a balloon sticks to your hair. It grabs dust for a few weeks, then it wears off.

After that the filter looks fine but is barely catching anything. You keep it in for another month, thinking it is doing its job.

The Dual 9 uses no static at all. The dust gets caught in the threads and stays there. At month six it works the same as on day one.

That is what the A in MERV 9A means. Camfil tested it again later, after a normal filter would have lost its static, and it still scored the same.

It should get dirty

Camfil promises 9 months in a home with a lot of dust in the air, and 12 months where the air is cleaner. If it falls short, they replace it free.

Expect it to look filthy when you pull it out. That is the whole point. A filter that still looks clean after a year is not catching much of anything.

What matters is what happens next. A cheap filter blocks the air as soon as it fills with dust, and your system has to push harder. The Dual 9 holds four times more dust before that becomes a problem.

What fills it up faster

Two homes can use the same filter and get very different results. It comes down to how much dust is in your air, and how much air you push through it.

Yours will fill up faster if you have:

• Dogs or cats
• A busy street, a gravel road, or building work nearby
• City living, where there is simply more in the air
• Sanding, woodworking or home renovations
• Anything else around the house that kicks up dust

A home with little dust in the air, no pets and a calm street can go the full 12 months.

If your thermostat fan is set to ON instead of AUTO, air moves through the filter all day and night, so it will fill up sooner. That is not a problem, that is the filter doing exactly what you paid it to do.

Easier on your furnace and A/C

Because the pleats stay open, air keeps moving through easily. Camfil measured up to 25% less energy used.

In winter, a blocked filter means less warm air reaching your rooms. On the coldest nights you feel it, because the house takes longer to warm up.

In summer it matters even more. During a heat wave, a blocked filter means your air conditioner cannot pull in enough air. The cold metal part inside can ice up, and once that happens you get almost no cold air until the ice melts.

Cleaner air also means your ducts and your A/C need a cleaning far less often, 25% to 50% less than with a cheaper filter.

Why Camfil

Camfil has been making air filters since 1963. Hospitals and labs around the world use them, in rooms where a single speck of dust is a real problem.

They were the first filter maker to put their promise in writing, after three years of testing in real buildings.

Which size?

Slide out the filter you have now. Read the numbers printed on the cardboard edge. Order the same ones.

Filter sizes are rounded off, and every brand does it. A filter sold as 16x25x1 really measures 15 1/2 x 24 1/2 x 7/8 in (39.4 x 62.2 x 2.2 cm). The full list is at the bottom of this page.

Not sure? Call (888) 315-0105. We do this every day, and we would rather you order once than twice.

Details

• Model: Camfil 30/30 Dual 9
• Score: MERV 9 and MERV 9A
• Fits: furnaces and central air conditioners that blow air through ducts
• Material: two layers of pleated polyester
• Backing: gold wire mesh, the easiest way to recognize a real Dual 9
• Frame: cardboard treated so it will not go soft in damp air
• Colour: white front, green back
• Thickness: 1, 2 and 4 inch
• Sold by the case, 6 or 12 filters depending on size

Warranty and returns

Covered by Camfil against defects for 1 year.

You can return your order within 35 days if the filters come back in perfect condition. Return shipping is paid by the buyer.

Exact sizes

The size on the label, then what it really measures.

Product photos are for illustration and may differ slightly from what you receive.