5 Things You Should Know About Your HVAC Air Filter

Filterbuy: filterbuy.com/qYEa1J0knccjlwe...
All my favorite HVAC tools: www.amazon.com/shop/thediyhva...
IF YOU ARE IN NEED OF GUIDANCE WITH YOUR HVAC SYSTEM, whether it is diagnosing a bad part, replacing your system, or help with sizing, check out our membership program here: / diyhvacguy
For a small monthly fee of $200, you will get assistance from myself when it comes to your hvac needs, whether it's sizing, diagnosing, or locating the correct equipment.
Follow us for more diy hvac tips & to enter for our giveaways!
Instagram: @diy_hvac_guy
Tiktok: @diy.hvac.guy
⚠️ Disclaimer:
This video is for educational purposes. Any and all HVAC repair work is done at your own risk. Any person attempting to deal with any type of refrigerant MUST have their EPA 608 certificate. The DIY HVAC Guy channel is not responsible for any possible damages or injuries caused by the use or misuse of the provided information.
Jobber: The #1 operations management software for home service businesses - Free 14-day trial + Exclusive discount: go.getjobber.com/diyhvacguy
The DIY HVAC GUY is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

[@LeeLeeLew]

Finally! A thorough explanation of what I’ve been trying to find out for a few years now. I’ve worked for an HVAC company for two years and this was more informative than any explanation given to me in the past. THANKS!

[@RobertViani]

You took the words right out of my mouth! Finally a good explanation.

[@paulnevins]

I run a MERV 13 to 16 depending on the season. I also buy 1/8 foam weather stripping that I put on 3 sides to make sure air can't bypass the filter. Since I also use masking tape to seal the forth side it has kept my unit dust free for 9 years when I checked it last with a 360 flexible inspection camera. My unit shook like crazy when it first ran and the tech blamed it on the MERV rating of the filter. It ended up being that the installer didn't remove the shipping bracket on the blower motor just like you have pointed out in other videos. Since the gaslighting was so bad and the install was so dangerous that my unit was red tagged and the unit was condemned, I just took the time to learn everything I could about HVAC systems to protect myself. I love that your are sharing knowledge freely to help others out that have felt helpless to the role authority abuse from nefarious certified experts.

[@RandomAxeOfKindness]

A lot of filters work about equally well no matter which direction the air is going through them. For most typical filters, the main reason to make sure the air flow direction is correct is that the filter is more heavily reinforced on one side. The stress on the filter goes up as the filter gets clogged, which makes the furnace tend to suck the filter into the duct. You want it in correctly partly because that extra reinforcement on the 'lee' side (the low-pressure side) is designed by the manufacturer to keep the filter from bowing or collapsing entirely. You really really don't want the filter getting sucked into the distribution fan!

[@rocbike4]

Thank you for your valuable information. I know most of your non-technical maintenance you share with us but it is peace of mind when it is confirmed by your videos.

[@Bowhunters6go8xz6x]

Great Info, I bought my present home a couple years ago and I didn't even think about the filter when I first bought it but I out afterwards that it had no filter and the previous owner had been running the system without a filter most of the time.

[@RapidRepair]

Great information for homeowners 😊

[@bluessrv1]

Love this channel...and I knew ZERO about A/C units until I stumbled across this! Another great video for the layman. 👍

[@BrittanyMartin917]

I wouldn’t take all his advice some is good but some is misinformation.

[@bluessrv1]

Give me an example. @@BrittanyMartin917

[@canyondan]

Thanks; for the video. Great information for everyone. Also during the cooling season especially we need to put some bleach down the drain line to keep the slime from building up and plugging the condensate drain then flooding and possibly ruining a floor.

[@JohnSmith-gq9gn]

How do I do that?

[@Diarrheabetes]

Big thumbs up for my boy, David. Really enjoying your videos and learning stuff.

[@diyhvacguy]

John weaver, as in from Holloway? No way. Hit me up sometime! I’d love to catch up

[@lizzieb6311]

Great information! Thank you. I replace mine every 30 days. I simply change it when I receive my electric bill…makes it easy. May seem like overkill…but it’s an easy way to remember and I do have several cats and a dog.

[@Brian13card]

Thanks for the filter I just saved a lot of money

[@danstojic5643]

Thanks David, I'm going to change it today!❤😂

[@mdavid2100]

Thank you for the valuable information.

[@bonitabeach3127]

Thanks appreciate your site.

[@juntang72]

Another professional tutorial

[@timcat1004]

I upgraded to a Merv 11 in Sept 2018. Big difference.

[@Honestandtruth]

I Totally 👍 💯 it depends on the Condition of Air inside a home. My House I change 3-time a Year is good Enough. Same as my Card Engine Oil. Twice a year ,..not every 3-months

[@n1iex]

Great video very informative thanks!😊

[@danwake4431]

i can still see light thru my filters at 6 months but i change them anyway. the filter says change every year but installer told me to do them every 6 months. I dont care the cost. i dont want to have to clean the A-coil and i want the furnace to run as long as it can. changing those filters even though they aren't cheap is peace of mind.

[@jaimechacon3361]

Great information.

[@charleseggers6176]

Great information 👍

[@emaxm]

Thank you.

[@munozinni]

Thank you so much for your videos I need to check your playlists for a video about how to check and clean the evaporator in our ac unit???👀😳You show some of that but even we don’t have air filter problems I would like to check and clean up the evaporator just to make sure is working properly and thank you for reccomending where you buy your 4” thick air filter…those “filtrete “ brand are very expensive 😢is like I should start a business making air filters Lmao 😂😂😂😂I’ll become filthy rich 😝 lol😂😂Gracias once again for sharing your videos and your knowledge with us all your followers… You have a great day now!!! Saludos!!!👋😊👋

[@nareshaeleti915]

Thank you very useful please make more videos

[@kevinmartin2096]

Awesome thanks

[@kauaireed9006]

Wow, thanks

[@kensejkora4424]

Great video. I'm learning a lot from all of your DIY videos. What are your thoughts about installing an inexpensive U-tube manometer such as those used for radon mitigation systems across the filter? One could drill a small hole on the air return side of the filter, and another on the circulation fan side, and have an easily visible means to measure the differential pressure across the filter. The more dust loading there is on the filter, the higher the differential pressure. One could get a baseline reading on a clean filter, and monitor the differential pressure periodically to determine if replacment is necessary. Granted, a clean MERV-13 filter will show a higher differential pressure than a clean MERV-8 filter, but getting a baseline on the clean filter would give you an idea when filter replacement is warranted. Keep up the great work on these fantasitc DIY videos. -- Ken

[@Xdonald331]

Here in Texas, we have a time called "pollen season". Stuff plugs up filters quickly

[@keith2498]

North Texas is the absolute worst. Dr. Said move to Hawaii. I didn't but a year later he shut down and moved to Hawaii do to allergies.

[@daveinthe6262]

Thanks!

[@diyhvacguy]

Thanks so much!! Very generous of you 🙏🏻

[@publicmail2]

Been using a Honeywell F50 for 30 years and is works great. SP is .1 and filters down to 1 micron, when dirty cells go into dishwasher. Evap, ductwork is never dirty.

[@keith2498]

How much are they? Found it. 828 on Amazon. Was probably cheaper 30 years ago. Thanks for the tip. Will look at installing one. I like reusable.

[@publicmail2]

Or the Ff300 is similar, I paid $400 wholesale, was $600 in 2000. Read the entire manual first, it does give off trace amount of O3 well below EPA standards, but is not an O3 generator. The best part is the Static Pressure on the system, which is the number 1 killer of efficiency on HVAC. It uses 7000volts positive and negative charge on plates to capture and hold particulates. They have a pressure switch with a delay, and uses about 30 watts on a 20x20 unit.

[@keith2498]

@@publicmail2 Looks like on Amazon it's about 850. Replacement filter OEM 90 bucks. Lasts forever though.

[@michaelmccarthy4158]

Hello AC Guy, What are your thoughts on washable air filters vs. throw away filters? Thank you :)

[@larrybud]

What do you think of filters that you can clean and replace, and any advice for a furnace which is in a workshop (wood working)?

[@Bothomas-vm5hz]

i use a merv 14 filter and only in mar thru may I have very bad allergy issues. By the way I change my filter every month, im located in florida.

[@bignicnrg3856]

Love the content!!! Do you have any video on whole house dehumidifier? Thanks

[@diyhvacguy]

I don’t but I plan on doing that very soon! Cheers

[@bignicnrg3856]

@@diyhvacguy awesome!!!

[@billy2bob63]

​@diyhvacguy What about surge protectors for the inside unit and one for the condensor? My HVAC guy is recommending this on my two year old system! What would be a good price on something like this installed by a HVAC technician?

[@hvac_double_agent]

What are your thoughts on the Filtrete 3M filters? 🤔

[@nathanchaney3290]

Something to chew on. This past month my furnace (which is electric with a heat pump) would not keep up when outside temp was in the single digits and was constantly running when temps was just below freezing with or with out the emergency heat on. I figured with the age of the furnace (17 years old) it was time to be replaced but i wanted a second opinion I called the local HVAC company to come inspect it. temp at the registers was appropriate and he did not see anything wrong he said. He was getting ready to leave when he heard a clicking noise start coming from the furnace. Turns out the relay or something to that nature was overheating causing the heating coils to kick on and off. with Having the door off the furnace during his inspection the relay had enough airflow to keep cool and not click on and off. He replaced my large Aprilaire filter with a standard 1in filter and the problem has not come back. so the large filter was restricting enough air flow as if it had a plugged filter. The filter was replaced 15days prior to this service call so i know it was not plugged. This company recommended this filter system couple years ago when i had problems my first year here. The a coil was very dirty so they recommended this option and it sounded good. we have fought with lack of cooling and heating since and just figured the furnace was in need of replacement. is there some sort of cfm requirements on these large filters? or is it lack of air flow due to shotty duct work in a double wide trailer that the large filters are just not a viable options in these cases. It is a coleman furnace.

[@garymarker3334]

hi David, I just replaced my old comfort maker 80K BTU/ 80% with a new Goodman, same specs. Your videos were a big help! I noticed right away some whistling from the filter area. I am using a brand new filter 1 x 16 x 25. Is the new blower that much improved because the filter is being sucked on much more than what I am used too? I read that if I design in a 4in or 5 in thicker filter it would greatly improve the airflow and lower the pressure drop? What do you think??

[@abc123fhdi]

you can also get a home warranty to cover repairs through your gas company.

[@michaelsmith5463]

QUESTION: If you do have whistling or a leak by the filter; what is the best method/product to "seal" the filter so the air is pulled through?

[@watuzi]

This video is so important , thank you for all the info. I think I have been replacing our air filter incorrectly. Our furnace is up in the attic on the second floor. We have two grates for the filters on the ceiling (20 x 30 and 14 x 14). When it was time to replace both filters, both arrows were pointed towards the floor, so I assumed this was the proper way. Three years I've been doing this wrong 😊

[@robtorres5518]

Tried filter buy, ordered differing filter ratings. Both were idientical and not labeled to tell them apart. Back to Costco

[@jack91522]

Is there a way to test your blower to see if it needs replacing?

[@daveyt4802]

Like to know how to clean the bottom of the A coil. And inspect it. Junk that got passed the AF.

[@a94cobra]

My 1" filters are full about 3 weeks in.

[@diyhvacguy]

Your airflow could be too strong on your furnace. That will cause buildup too fast as well as other problems.

[@6319ghostrider]

I added a hard start kit on my ac/heat pump and now want to install a soft start kit. Do I remove the hard start before I put the soft start kit and will it replace the boost it needs to start?

[@kjisnot]

I have an Aprilaire 2400 filter box in my downdraft air return. It had a 13 MERV filter (16x25x4) for about 3 months (previous owner left it). It's advertised to last 12 months. This summer I noticed condensation on the outside of the return duct above the filter box. I had water dripping. I ordered a 11 MERV and it's been fine. Aprilaire does not make a lower MERV filter for this so I guess that will have to do. There are no third party suppliers of this filter. Even if you raise the filtration level it may still cause you headaches like a dirty filter.

[@scoobtoober2975]

My evaporator iced up when i used a higher merv filter. Switched from a 13 to an 8 this summer, ac has never iced up.

[@davidsimon6011]

Question: Do you have any recommendations for wildfire smoke whether it be for the outside unit or the Filter?:) Thanks for another great video 👍

[@chezchezchezchez]

If you live in Maui, change it

[@IdahoFluke]

What are your thoughts on a electric filter system? My house has one (installed with the original furnace in 96) But I’ve never ran it until today.. I’ve just had 4 inch filters on there the electric filters go. (How it was when I bought the house in 2017) I did notice there is air leakage around the filter, so I’ve started looking at how yo get to the coil and check it.

[@pumpupjam9648]

When COVID hit, I got a Merv 11. But it didn't filter out the cigarette smoker below stench. So I moved up to a Merv 13. That helped. Now that smoker has quit, I went back to Merv 8. My furnace clean as a whistle. The heat pump is dirty. I need someone honest, but unfortunately, there is none in my community. Cannot do the job myself, it's surrounded by other heat pumps. And no electric to plug in wet canister.

[@mikeb4629]

I had an older furnace along with an old electrostatic air cleaner from the previous owners that has never worked. But because it sits between the return duct and down by the blower like the one in your video I left it. A company came to clean our HVAC systems and recommended replacing the filter with an aluminum electrostatic filter. We ran into issues a few weeks later where the furnace would not stay lit. I ran through a lot of your troubleshooting along with turning the unit on and off until it stayed lit. I finally had an HVAC contractor come out and they said that new filter had burned up our furnace and ended up replacing the entire unit. However the cleaning company is saying that isn't possible. Any ideas? Currently there isn't even a filter in there. Thanks!

[@rickdewoody-fe7fj]

Where can i take type 2 test skillcat only. Does universal test help

[@LennyTim]

Cheers :)

[@sczygiel]

I have a different bucket question. My A coil looks clean but the air does not get through much. If I run the fan it blows a ton of air but somehow the air flow through A coil is minimal. It also gets frosty/ice builds up on the lower part of it (where the supply line is attached. I wonder if it is just dirty inside or its refrigerant lines are clogged. I will try to wash it but im not sure if it will help much it really looks pretty clean. Can you suggest anything here? Should the airflow be intensive through it?

[@varanidguy]

I'd like to upgrade the thickness of my filters, but the system takes two 20x25x1 filters - side by side - inside a register in the hallway, the rest of the equipment is in the attic. Is there a replacement register (I know it's not a register technically but I can't think of what else to call it) that I can install in the hallway to accommodate thicker filters rather than going into the attic and attaching it up there?

[@edbouhl3100]

I added a 4” filter rack after my existing 1” rack. Dropped the 1” filter down to a MERV 8 to catch the dog hair and to help the 4” MERV 11 filter last longer. I change the 1” filter every 1-2 months and the 4” filter every 6-9 months depending on the ‘light bulb’ test. So far no air flow issues 2 years in.

[@user-pi2gd8ps3p]

what if the opening to put in my ceiling air filter isn't cut smoothly so i have to force my air filter in? would it still work that way ?

[@ihatesocialnetworkin]

I cannot find your eval coil cleaning video.

[@richc9890]

Where can I get a 4" filter rack?

[@TheViking34482]

Where can I get a simple glove to protect from Freon

[@BillyBobDingledorf]

Sigh. I can't get to my evap coil. I really need to have a panel put in.

[@eurolife8015]

Do you have your video out now for how to get the EPA License for the Freon purchase? Thanks. Cheyenne

[@diyhvacguy]

Yesir, you can find that in my library 👍🏼

[@LHW2208]

Please help, idk if I'm being scammed. My HVAC was turning on and running fine just blowing hot air. Had someone out to look at it they said the capacitor was bad they replaced it and then said the compressor is seized. It was working before he touched it. They want to give a quote for replacement of everything. What should I do?

[@scoobtoober2975]

My evaporator iced up when i used a higher merv filter. Switched from a 13 to an 8 this summer, ac has never iced up.

[@diyhvacguy]

Yea the bigger merv you go, the better filters ruin, and the more restriction. Systems can’t handle higher merv rates filters if they aren’t sized properly or don’t have the ductwork to support it.

[@scoobtoober2975]

Yep, I need to check static pressure and sizing. It's an old house that was re-worked for this a while ago.@@diyhvacguy

[@ByGraceThroughFaith777]

So are you using a 5 in thick on a 4 in slot? I stopped my filterbuy subscription cuz the filters were too small.. any tips would be much appreciated! Thanks

[@diyhvacguy]

If you have the Honeywell filter rack, it’s actually a 5” filter that you need to order from filterbuy

[@socrates2706]

Is it correct that filters above a 5 restrict too much airflow and also stress the blower motor?

[@diyhvacguy]

Not at all correct. The thicker the more surface area

[@socrates2706]

@@diyhvacguy Referring to MERV rating above 5.

[@edorofish]

The link didn't take me to the 1" to 4" upgrade video.

[@diyhvacguy]

Sorry about that. Got that fixed 👍🏼

[@rtoguidver3651]

I use to blow the dirt out of the filter every few months, now I replace them twice a year....

[@chezchezchezchez]

This is the first I heard “ look at it, if it looks fine keep it in for another month” Is that the standard rule that everybody accepts? I’ve been wasting a lot of money if that’s the way to do it. Thanks.

[@diyhvacguy]

That’s right. Checking it every few months gives you your baseline. So if they’re not getting dirty until 6 months and you are replacing them every 3, you are throwing money right out the window 👍🏼

[@markme4]

My AC guy said I need a tune up and since its a 5 ton system it would require 8 new spark plugs 🤷🏻‍♂️

[@diyhvacguy]

🤣

[@TheViking34482]

No answer

[@geezberry8889]

change filter every month?!!!

[@maryg.7790]

I bought the Filter buy filters at a great price and they are working great! $44 for 6 merv 11 .. basically 1 year's worth. (Not sponsored)

[@patrickvillegas3885]

That is a 5 inch filter

[@keith2498]

Some systems can't handle thicker filters. They cause less airflow and freezes system up.

[@timcat1004]

The thicker pleated filters have less restriction because of the larger surface area.

[@keith2498]

@@timcat1004 I mean it makes sense to me when he rolled it out. I would be curious on studies. I live in Texas. I have used probably 5 or 6 technicians. All have said airflow is reduced and it's harder on the fan motor. Had one house where family used thicker filters. AC tech said do you hear that squeaking. Watch this. He put in 1 inch and it went away. He said the thicker filter is causing more wear and tear on motor. Not that old of a house. Not saying you are wrong. I would like to hear what others have to say about it. AC guys. Non AC people also. I always appreciate these videos. Just makes it look simple Like I want to learn to do it so I can help people out at church or neighbors. They always go out when someone is in a jam or on a weekend at midnight.

[@realSamAndrew]

It's not the thickness, it's the density. Higher merv rating means higher filtration and higher density material. Meaning more restrictive, less airflow. Think about how hard it is to breathe through a super high index mask. The thicker width filters only pass the air one time, there's not 5 layers, only one layer spread over a larger area.

[@keith2498]

@@realSamAndrew I can grasp that analogy. I would just ask why a system freezes up on both ends and freon is perfect. Then we switch to a thinner filter and it unfreezes? Maybe you are right. The material on the one inch was more porous?

[@realSamAndrew]

@@keith2498 exactly right. The classic "cheap" filters with that scratchy fiberglass thread are very porous, and to my knowledge, you cannot buy the 4 or 5 inch filters with the cheap material. They are always the high density HEPA grade material. The old school filters were always 1 inch, but they had low end filtration as well. It was explained to me that the purpose of a filter in your air handler is NOT to filter the air of contaminants to people, but to protect the coil and the system from dirt. Later on, the consumer society sold everyone on the idea you are getting sick from the indoor air. Maybe true, but the machine is not designed to run while starved.

[@chezchezchezchez]

This Filterbuy sponsor the damn video?

[@armando2928G]

Filter buy sucks don’t buy

[@dmbdmb3828]

☕️