MervFilters MERV 8 AC Furnace Filters (6-Pack)

MervFilters MERV 8 AC Furnace Filters (6-Pack)

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Two 6 packs of 20x20x1 is the perfect amount for three ghetto air 3000s!



Still no 20x30 filters


Need 20x30 too.


Will these fit in a ceiling mounted furnace?

According to the Amazon reviews, other customers have been able to fit this in a ceiling mounted furnace - you can read the reviews here: It sounds like what’s most important is that the filters match the dimensions of your furnace.


I got a few messages asking for the specs on how to build this and why I did; here is my information:

This is just four 20x20x1 merv 13 filters (3m 1900 model) and a $18 Lasko 20" box fan.

How to Make a DIY Air Filter | Ask This Old House - YouTube ← Video on the subject. ← Filters I used, they offer 20% off when you order 4+ which is the best price I’ve seen on the 1900s. I use the 1900s due to their static pressure to capacity ratio being one of the best on the market and their ability to cut out allergens from the air. I have asthma and a newborn at home and feel the safest with it compared to the competition. Citation for filters: Which Furnace Filter Brand is Best? Let's find out! - YouTube ← Fan I used. Be warned they can be broken if dropped (learned the hard way). They are the cheapest fans I could find that would work with 20" sizing while still having enough passive cooling to not overheat. ← The duct tape I use. Per Project Farm it performs the best out of any duct tape for bang for your buck when it comes to strength:price ratio. Citation: Which Duct Tape Brand is the Best? Let's find out! - YouTube

It takes up a lot of room but works great especially when doing something like sanding walls or things that put fine debris into the air. Gets amazing CFM compared to retail air purifiers that cost hundreds. Using four filters in a box config rather than just one on the back of the fan increases the surface area which reduces the static pressure and prevents the motor from overheating on the fan. I am paranoid thus why I choose to use that method. I just used the box the fan that came in as the stand to seal it all up.

I have made some changes since that picture was taken due to air flow testing I did (cling guard plastic on the fan face to find what parts of the air path were bypassing the filters and going around the fan face instead.

This is the Ghetto Air 4000 with the mod:

This is the original Ghetto Air 3000 from the top:

Sorry for the poor picture quality; I am redoing huge parts of the house and have limited time to take the pics.

If I ever purchase a CFM gauge I’ll provide more specs of the differences in CFM and static pressure.

Is an $800 purifier best to clean your home's air? We lab tested 5 top brands - YouTube ← Comparing Lasko Fan + Filter VS $800+ air purifiers like the top end Dysons.


I buy these by the brick and take them apart for the filter material - I then use the filter material for my windows on high pollen count days or during fire season and I put them between my air return vents and the floor so that dust and debris doesn’t get sucked down into my hvac unit. I also use a merv 13 on the hvac unit itself and haven’t had any issues with pressure or short cycling.

Pictures of vents below:


So once upon a time an HVAC tech I know and trust told me “you know… people buy these high efficiency super awesome furnaces that move so much air and then spend tons of money to block the air flow on purpose, making the furnaces crank harder and burn out faster.”

He advised using the most basic, cheap filter we could get, saving the money AND the unit. I’ve done that for years.

I have bad allergies. And they definitely are no worse with the basic filter than with all those fancy filters. I’ve since added a dog to the mix, too. My analysis is that these allergen filtering filters are a modern snake oil. Save the money and buy some stuff in the WTF pricing later or something!


That’s anecdotal at best and plenty of studies have shown the complete opposite of that. Basically everyone I hang out with on a daily basis is in HVAC, plumbing and IT. Yes, I absolutely agree every HVAC guy will tell you to go with the cheapest merv 8 filter as they’re all relatively the same at that point. With that being said there is a huge difference between different grades of merv filters. There are plenty of particle count studies done to show not all filters are equal and the majority of the cheapest ones barely do anything at all besides to the largest particles.

Using high static pressure filters will absolutely burn out your HVAC unit faster if it’s incapable of handling it, which is common sense. I highly suggest checking this video Which Furnace Filter Brand is Best? Let's find out! - YouTube ; typically speaking the larger surface area and more pleats, the less likely static pressure will play a roll in your HVAC’s longevity (with regular filter changes).

It really depends on how sensitive you are to outside environments where you live in the end. If you’re someone who has to carry an EpiPen everywhere you go, spending $19 on a merv 13 filter is well worth it over a merv 8 filter if your unit is built to handle it. We only use merv 8 filters in our DataCenters simply because allergens don’t matter to computers, but dust does. If you’re using filters in a hospital, you are not using merv 8 filters for obvious reasons.

There are also a ton of house plants that do amazing jobs at cleaning the air quality and can remove toxins from the air created by things such as air pollution or cooking pans. Granted you need like 3+ healthy sized plants per human per room to create enough clean oxygen to be effective and there are specific plants that do their work during the day time and others for bedrooms at night.


I agree. My doggo developed such bad allergies that his doctor thought he was in heart failure (he was previously diagnosed with a level 1 heart murmur). After I added my merv 8 to my air returns, popped in a merv 13, and made some other changes his allergies went away and he’s doing ok.


Looking at the photo from the perspective of directly at the fan (looks horizontal), I’m thinking that is would also work that way - by putting carboard on the bottom side (side where fan feet are) and move the fourth filter onto the back, and then your GF would be dual purpose, as a filtered fan as well as a house filter.

And thanks for the effort of detailing a build-kit for your unique share!


I’m unfamiliar with using pets in one’s air cleansing strategy. How does that work exactly? (I have a Golden Retriever and I’d love to put him to work removing the thick layer dander and dirt he drags into the house, so’s I don’t have to…)


Need 24x30

I did not see where they said that their dog helped with cleaning the air. He/she said that they had bad allergies and in spite of adding a dog to the mix the cheap air filters did the job.

Yes! They are exact. 14x25 was 14x25 and fit snuggly for me.

Wrong. I’m a HVAC tech retired after 30 yrs. The cheaper filter will not filter air as well, the ‘spun glass’ filters will let dirt into your system causing damage. An air handler doesn’t work harder with better filtration, in fact the amp load on the fan motor goes up with more air going through the system & goes down with the slight amount of proper filtration.
Be sure to change filters on a schedule! For most homes, a merv 8 to 11 is just fine. The merv rating actually goes up slightly as dust builds up on the filter. I run two 20x20x4 merv 11 filters in my system and can go about 5-6 months between changes. Running one 1" filter, I’d check it every 2 months or so.


You have a Golden … no way your gonna keep your house dust and dog hair free. My golden passed away in 2018 and I’m STILL finding gold strands of his butt fluff and tail hair in things.




@woot why are you charging $6 shipping/handling if I’m a prime member?