Why You Need To Stop Using These Filters To Purify Your Air! What To Use Instead

I'm curious, have you been using these filters or used them in the past?

I would argue that HVAC designers need to stop designing return air ducts and grilles to the minimum size for a given airflow. A modest increase in duct and grille size would allow enough airflow with a premium filter to avoid this issue. When I did my own system many years ago, the pro I brought in to charge the A/C was impressed and pointed out the oversized return. I told him I did it on purpose to allow for better filters. The total extra cost of the oversized grille and short duct run? Around $50.

Moved here 2 years ago, air system filter is MERV 11 , 15" X 25" X 5" . It worked well cleaning smoke when forest fires were in full fury.

When our HVAC guy did our house he sized the system for 20”x25”x5” MERV 11. Our house doesn’t get dusty and it has helped with mild seasonal allergies. We also installed an air sanitizing UV system. No regrets.

I've had many a AC tech call the low MERV rating "rock stoppers", because that's all they will stop!

23 years doing HVAC installer, tin knocker, service tech, service manager, and instructor working in residential, light commercial, and commercial work. I pretty much agree with this whole video. The only thing that makes it hard to say this is the filter that you should go with or not because everybody’s duct system is different, and also depending on equipment, registers, and zoning it makes it really difficult just to say this is what you need to go with and you’ll be good. So my recommendation is if someone only had a 1” filter slot they could get a couple different filters and have a reputable company come out and check total static pressure while changing of each and then make your determination after you actually measure instead of guess. It is always better to have a media cabinet 4”+ filter you will be able to have much more surface area and be able to have a higher efficiency filter at a lower total static pressure. FYI MERV 16 is equivalent HEPA efficiency. Hope this helps!

When we had our new furnace installed, the HVAC contractor put in a 2 inch filter holder, and increased the furnace intake area. Made a big difference in home comfort and the furnace handles a MERV 8 no problem.

Have you or any of your readers noticed that lately (some) filter manufacturers are making their filters ¼ inch smaller than the posted size on the wrapper? This is causing extra air noise inside the house coming from the filter cage in the ceiling. What is causing this because I do not agree with selling us consumers short. The the way - great video and I absolutely love your channel as you have helped me maintain my home much better and have saved me considerable money.

My local HVAC company educates customers just as you have in this video. I've been using the 3M Dust Reduction Level 300. MERV rating not on package as you stated. It is located on the filter itself. Back side on the bottom reads MERV level 5. Thanks for all you do for us!

I watched another video "Furnace filter-which furnace filter is best". The tested a wide range of filters using a manometer. He found that the 3M filters were quite impressive for the low pressure drop across the filter. We have been getting a lot of fire smoke here in Alberta. I installed a thicker filter box to use 25X20X5 filters. I installed a Merv 11 and use it with 2 Honeywell extra large room Hepa Air Purifiers with good results. Keep in mind that a lot of house hold dust will settle out before it makes it into your return air to be filtered so don't think you can throw away your Swiffer any time soon!

Working HVAC I replaced a filter that was so plugged it almost was sucked into the return air vent. I could hear it whistling upon entering the front door. I pulled it then checked the system to verify it was the only filter. Told the homeowner that it was the filter and I could find nothing else wrong. It was less than a month and I had the same call, same problem. Had to explain that when a filter was plugged no matter the time in place it needed to be replaced. They had just moved in. I think it was the sprinkle carpet deodorant that was popular at the time that put a lot of powder in the air when vacuumed. I think it was a heat pump unit.

a very timely video! I live in New Mexico. In the desert! it doesn't matter what filter i buy i can't seem to knock the dust down that gets in the house. This has pointed me in a better direction!

I custom built a pre-filter box for my whole house air filtration system. The box has a series of six slots with six inches between each slot and twelve inches between the opening and first slot as well as the sixth slot and the exhaust which goes into the actual system for a total of ~65". I also use a UVC lights at the beginning and end. I use 24x24" filters in the following order: Electrostatic metal washable MPR (MERV) 300 (5) MPR (MERV) 600 (7) MPR (MERV) 800 (10) MPR (MERV) 1200 (11) carbon MPR (MERV) 1500 (12) System filter: MPR (MERV) 1900 (13) I clean the metal electrostatic weekly or better. The rest get replaced 1-12 months. My system has an airflow monitor and has only gone off twice after wildfires. Note that it cost me about $75 to make the pre-filter box and has saved me dozens of times more in expensive filter costs and maintenance as the system and downflow ducts remain very clean. Yes, I did go overboard but enjoyed the process and final results.

I too once installed a higher rating filter which was restricting air flow, and when the unit shut-off, I was able to hear the metal pop as it deflated. I now use an FPR #5 rating, works well and there is no decompression sound after it shuts-off.

never had a problem with my systems and as an asthmatic wholeheartedly will say there is nothing better than a high end 3M to ease your breathing and deal with allergens. Happy user since the mid 80’s. 1500 minimum, which captures cooking odors and smoke as well. if you want to keep the large particles from clogging the better filters, sandwich one of their basic (blue mesh washable) filters ahead of it to catch those and change that one out or wash it when you see it load up, the carpet of dust that forms is what helps reduce service life of the better filter.

I use Merv 4.But I have two house filters the same you use,that run on low but have sencers to up the fan speed.Great video.Never a problem with the furnace.Plus the house cools and warms up quicker.

I had the furnace and the AC serviced last year and I asked about the filters I should use. The answer was to avoid both the cheapest filters and anything higher than MERV 8. So, pretty much in line with what you're recommending.

this is good information cause I have used these in the past. I will be switching next season thanks so much 😊

Didn't scroll through all the comments but every quality filter should have its airflow ratings printed on it or the packaging somewhere. Your HVAC system has ratings that it was designed for. You should be able to match them up. Issues arise when the entire system (furnace, AC, ducts & filter) is not in harmony. Our old house was an example of this. Not enough intake air in original ducts and the AC was running too a high a fan speed that made for short runs and the humidity remained high. This also stressed the filter. Corrected these issues and was able to maintain correct air flow with MERV 11 filter. It is always a sum of all the parts in play.

I'm an Engineer with extensive filtering experience in industry. I totally disagree with you. I have bern running the 3M Filtrete filters for several years, with zero problems. I live in Phoenix, and the air here is totally polluted. These filters work great for removing all types of contaminates. I also add a carbon filter on top of the filtrete filter. The AC moves air with a fan, so these filters aren't going to affect the compressor, which is the main power consumer. The fan can handle a bit of airflow restriction. Like I said I have not had any problems witj my AC, and its hotter than hell here in Phoenix. You should see all the crap these filters pull out of the air. I also run HEPA air filters in our bedrooms, but they can't process the amount of air, that an AC can process.