SHOCKINGLY Common AC Filter Mistakes Costing You Hundreds Or More!

In this video, I'll show you the biggest mistakes homeowners make when changing their AC filters. These mistakes can end up costing you a lot of money in the short and long term. They can also impact your health. Learn how to avoid costly repairs, improve air quality, and save money on your energy bills!
🧰 Products In The Video 🧰
Air Handler Filters: amzn.to/3PNyB4b
Levoit Small Air Purifier (1,095 Square Feet: amzn.to/4aJt3PY
Levoit Medium Air Purifier 400S (1,980 Square Feet: amzn.to/3Jsu3g9
Levoit Large Air Purifier 600S (3,175 Square Feet): amzn.to/43KZfR1
🎥 Related Videos 🎥
Top 5 Things AC Companies Don't Want You To Know How To Do!: • Top 5 Things AC Compan...
How To Clean Your AC and Coils Like the Pros Do | WILL Make Air Blow Colder: • How To Clean Your AC a...
How To Quiet Your AC to Normal Conversation Volume: • How To Quiet Your AC t...
Check out and join our channel memberships for some cool perks and to help support the channel! / @howtohomediy
ALSO, here is our How To Home Amazon Store, where you can find many of the tools, items, and shirts I use and wear in my videos! amzn.to/3mcqu1E
My KZbin Filming and Editing Gear: amzn.to/3kqqkGl
Thank you for watching and for subscribing. You can support the channel at no cost to you by using one of the above affiliate links. This helps support the channel for new content!
Blessings,
Adam
How To Home assumes no liability for damage or injury. How To Home highly recommends using proper safety procedures and professionals when needed. Our content is for entertainment purposes only. No information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not How To Home. How To Home will not be held liable for any negligent or accidental damage or injury resulting from equipment, tools, electrical, fire, electronics or any items contained in this video. Attempt projects and repairs at your own risk.

[@rickspies252]

Funny, I’ve lived in three regions of the US and the furnace is always vertical and located in the basement or the garage. Putting it in the attic is plain weird and perhaps the least convenient location. I pity the service tech who has to service the AC in summer in an attic. Also, my air filters have always been in pairs at roughly 45° angles, after the furnace, not before. I think they would last longer in this configuration, distributing the particle load across two filters. I’ve always bought MERV 9 or 11 filters, by the case. Personally, I’ve found the best prices on either eBay or Groupon, but not lately on Groupon. Retail prices are crazy high.

[@HowToHomeDIY]

Be honest, have you ever made any of the mistakes shown in the video? Unfortunately, these mistakes can end up costing you a lot of money in the short and long term. I hope this was helpful! ❄

[@sunshine3914]

I’ve done a lot of housesitting in my time, & a couple weeks ago the unit for lower story started blowing hot… wasn’t able to locate the filter. I come from an area where two story homes are… were a rarity.

[@sunshine3914]

SE TX. My unit is 33 years old, only two service calls; one to replace freon & the other, a tripped breaker 😅. I had just purchased a pack of HE filters & my AC guy (2nd generation) told me they would put as much strain on an AC as a dirty filter would, & that I was better off using the cheap green ones.

[@TriggB44]

What brand is that???!!! 33 years is a good long time, I'm impressed!

[@krisone63]

same here, I use the cheap green ones...

[@JD-mm4ub]

Mine just turned thirty and I use a merv 6. Anything higher and my ductwork starts banging!

[@johnlandacre767]

Our unit is high efficiency Carrier gas furnace, electric AC. Was installed when house was built. Date code 1987. Almost 38 years old. I use merv 8s. When we bought the house, it had a fancy Filtrete, maybe 12 in it. Don’t know what previous owner used through the years, but the system works perfectly, both heat and AC. I’m not letting go of it till it stops dead! I doubt they build them like this any longer. Btw, the ac unit is dated 2016. But made in Mexico.☹️

[@cejkwo100]

I never use pleated filters, I always go with the fiber filters so I get the best airflow

[@teddyknight4762]

You do a very good job explaining these thanks

[@j.m.7056]

All 7 of the houses I've lived in have had filters installed at the air return. Usually in a hallway.

[@Mojo32]

It is that way in my current home. Is that the only filter? Or would I find another one on the furnace itself?

[@brianpowers1116]

@@Mojo32 When I had my AC replaced about 15-20 years ago, they told me to stop using the filter in the air return in the hallway and only use the filter at the unit. My guess is that it is unlikely that there would be two filters, as this would restrict air flow too much and cause either damages or inefficiencies to the AC unit. Only way to find out for sure is to have your AC guy come in for a checkup and ask the question then.

[@Rhaspun]

Yes that's where my filter is at. I use a 3 inch deep filter. It causes much less back pressure than a 1 inch deep filter.

[@Mojo32]

@@brianpowers1116 Oh okay, makes sense. Thank you for replying to me

[@cain1s]

Your other video discussing the thicker filters helped me a lot.. My unit was just starting to have problems, I found your video on how to change a capacitor(excellent instructions, thank you.) After watching that video i found the one on thick filters. That's what killed my capacitor, I had switched over to thicker filters a couple of months ago. It iced up in 90 degree heat and stopped working. I went back to thin filters after changing the capacitor and problem solved. Thanks so much for these videos!

[@pit4955]

Great video thx for the info, we had a home built 3 yrs ago so I just went up to the attic to check the filter for the first time never knew there was a filter at the air handler I do change the filters at the air returns. I removed the small door at air handler as you pointed out and was surprised to see there was no filter in the compartment after researching I found the correct size and ordered a few. My question could there be any damage to the unit or do you have any suggestions that I should be looking for? Again thx for all the great info👍👍

[@hamop78]

Most a/c units specify the highest or recommended MERV rating for the unit. It’s a mistake to go to a higher than recommended as it will make the unit work harder than it was designed. Just because the filter takes out more or smaller particles of dirt, it’s a mistake to exceed the MERV rating for the unit.

[@mlinton3007]

Great info. Thank you so much. Great voice and articulation. Super

[@HowToHomeDIY]

You are very welcome! Really glad to hear you liked it. Thank you very much for the kind words and taking the time to leave that feedback! Very much appreciated.

[@robertjordan2041]

Wow great video,packed full of great information,Thank you.

[@nancysanchez3722]

I can’t thank you enough for your informative videos and always to the point. Learning and applying your tips. Keep it up 👍🏼

[@JeffpRRR666]

Thanks for this, I use Merv 9 pleated filters and change them out every 5 to 6 weeks. And they are packed full of debris so I never let them go longer then 6 weeks.

[@svenska572]

Always great videos! I enjoy your delivery of the information. I recently had a debate with a neighbor about MERV ratings and what is reasonable for our systems. Our houses are newer - built within the last 12 years - and the air systems can handle MERV 13 filters just fine (according to the HVAC company who installed these for the builder). I can see where an older system might not be able to handle a higher MERV rating, taxing it too much, but a different HVAC guy told my neighbor that it's bad for our furnaces. He sold them on a UV system with a different filter system. I'll stick with my 13 and change it appropriately.

[@HowToHomeDIY]

Yeah it is really going to depend on the system installed and the thickness of filter. Most are not equipped to be able to hand a high MERV 1" filter. Appreciate the input!

[@danielcline650]

I've had several HVAC service techs mention that the air filter on the return isn't so much for air quality as it is to protect the air handler from getting dirty/dusty and failing prematurely. I prefer the method of a lower-MERV return air filter, enough to keep the air handler happy, then use separate room filters.

[@emilg]

I've always gotten the higher merv Nordic Pure pleated filters. They are amazing. Pricey but worth it.

[@berthongo8531]

Secure the power before changing the filter? BS. But then I started thinking about some of the people I know. Yeah. Secure the power. How to tell if your filter needs to be changed? Just install a manometer. 😁 Or wait until the A-coil freezes up. 😂 Trust me. I know people that have no idea that this may happen. I explained it to my wife and she understood the reasoning right away. Whenever she thinks the AC isn't working correctly, she trots down to the basement and checks the tubing for any frost. Great video!

[@meeticnett]

Thank you for the content. What if my unit did not come with a filter chamber cover?

[@jasondalton6182]

I live in Arizona. Ac units here get a hell of a workout. When I bought my home it had the original ac units in it and they were poorly installled 4 years prior. One of the systems servicing the weather side of the home didn’t even have a return in that wing of the house. The owners were using filtrete merv 11 filters but not changing them regularly. I continued using them but upped the changeout game a bit. We had to replace both units after 4 years. Probably an issue of constant running and air flow restriction. I used the merv 11 filters for another year but then started using merv 8 and air cleaners in the house (your suggestion). I’ll probably use up my merv 8s and shift to merv 5 or so. The air cleaners really do help. I’d like to squeeze as much life and efficiency out of these unites and hopefully they will live for 15 years. Really appreciate your channel sir. Great information here.

[@troy3456789]

You may want to install another return. Another return will allow you to use more restrictive filters without imposing additional load or strain. I had two 16x16 returns. I had my HVAC guy install a 20x20 return in our bedroom ceiling. Life is way better now. It was worth every cent of the $300 we paid for it.

[@jasondalton6182]

@@troy3456789 that was the first thing done. We think that the builder made a last minute decision to add a second unit but was too lazy to penetrate the firewall that had already been completed. We corrected that mistake.

[@MrKeithsplace]

The biggest reason to pay attention to airflow direction, is support for the filter, seen several times filter being sucked into blower housing. Always hated cheeping out installation, not putting in proper filter slot. Many for years just leave a slot between the blow box and duct.

[@MrLuigi-oi7gm]

Where I live in the US, it is standard practice to install the filter housings at the returns. Not only does this provide much more filter square footage to improve air flow (I have 4 filter housings in my house), but it keeps the ducts clean since the dirty air is filtered BEFORE it gets into the ducts. For those who are fond of using those MERV 1 fiberglass filters, I would reconsider. They let so much debris through it is most probable your evaporator coils and fins are filthy 🤮 and dramatically reducing the efficiency of your system

[@yancyb1948]

You're the best, great information for home owners. My only suggestion, is, rethink your extended details. Speed things along. Less duplicate articulation. Details are great, less verbiage. Keep up the outstanding presentations. Hooyah, have a marvelous weekend, stay FROSTY. USN Ret.

[@troy3456789]

Not everyone is an HVAC expert

[@PlymouthVT]

What I do is tape the ac filter in. Most metal filter receivers in the house not the type he has in the attic are very sloppy so the filter does not fit tight there's a gap around the edges. Soon as the filter gets a little dusty the air being sucked in under pressure will find an easier path which it to scoot around the filter and thru the air gap. I use gaffers tape and tape the edges of the filter to the receiver so its airtight seal around the edge. If after 30 days your filter looks like new you have a air gap leak especially if you have pets and rugs.The taping assures no dust gets pass the filter and the filter is working to the max and that's important becasue if not your evap coil in the attic will get clogged. AC guy says your evap coil is pretty clogged and you say but i change the filter every 30 days!!! Btw, I have found the Walmart Great Value MERV13 to be a great filter and a great buy. I buy the gaffer tape on Amazon.

[@Leonardokite]

What are your thoughts on the washable 1 inch thick filters?

[@pwerboost]

I'd been using Merv13 for 5 years and i had never had any problems with my AC but i also change them every 3 months regardless or how the filter looks like.

[@peggyzion8448]

I've had my capacitor go out 2 years in a row, during July, on a new unit. I live in an area where temps can reach 115 degrees during summer. I watched your earlier video on cleaning the coils, so washed the unit off, and it still went out. The repairman said it's because the manufacturers of the capacitors changed the type of oil they use causing the capacitor to overheat in our climate. Maybe so. I'm not sure how to fix that issue, though. This year, I'm focusing on reducing air restriction, just for the summer months, by using those cheap filters. My theory is the Merv 5 filters were too restrictive during summer for my Goodman unit. What are your thoughts on the matter?

[@ericallen7200]

I buy MERV 6 in bulk in both sizes I need. 3 year supply...changed every 2-3 months. Have HEPA air filters running near my 2 return locations. Chef's kiss. you are the man.

[@frankthetank5013]

My HVAC uses 20x25x4 filter! They are $45 each 🤦🏻‍♂️

[@Bassmaster1256]

A good quality air filter will have the wire mesh on the air handler side in case the filter disintegrates and will also have a very minute amount of oil on the air flowing into side. These are the filters I've been using for over 40 years.

[@clarencewiles963]

Air flow directions has more to do with the wire / strapping to stop the filter from getting sucked into the chamber. With out this reinforcement an old filter would be sucked in!

[@majorburke9735]

As a new homeowner, I made that “air flow” direction error a few times.

[@boatlover1875]

I have yet to see any videos on my situation. I have a 2200 sf house. I have five filters in ceiling air returns. 2 20 by 20 and three 14 by 14. This is obviously different than the single filter at my furnace. This is obviously more filter area. Is it okay to use a higher MERV? The two in my main living are collect more dirt but not crazy. Combined they are much more surface area in the one you showed on your furnace. Would love to see some recommendations there.

[@d1gardner]

Tip: write the date a filter is changed on the filter. Also, I have an air compressor, so I blow out filters several times before replacing them....I direct the air in the reverse direction air flows through while in use. As noted about writing dates on filters, I write the date it's blown out.

[@billkohl449]

I have 2 filters in the hall ways. If the home. But Do I also have a filter at the main unit in the attic of the house?? I have a Bryant system with two units in the attic and two big units outside the house where the condenser is located! Do I have filters in the attic at the main units???

[@nowthatsfunny1]

I use a UV light, 2 hepa filters and a dehumidifier down here in Florida. Cuts my electric bill down some and house is a lot nicer.

[@shamrock5725]

Do all air handlers have internal filters? I have a filter i just replaced that is in the walkway ceiling below the goodman air handler location. Is there a second one i should worry about?

[@sziltner]

On-line FilterBuy! 👍🏻

[@SteveH-nf2ts]

Good advice, avoid filter over merv 8 IMHO. I got cats and dust its sadly Florida. I live with it. Better than replacing a air handler motor. I got/get 3 months on every Merv 8 pleated airfilter, np. NOT PAYING 20 plus bucks for 1 filter, that is just nuts. I buy 12 or more at once. Lucky for me we have a filter maker here. BUT I check them every 2 weeks in summer. in winter not so much i had them last for 6 months. Granted I got tools that measure everything still.

[@barrynolan5435]

My 0.02 cents : Write the replacement date on the filter so it's easier to get a visual as you inspect. Also, pass along how to get the correct size for the unit. You were so close in the video but never mentioned it. Still got a thump up!! 👍

[@edwinhuizinga3042]

Also when the return unit is not properly sealed or any other leak on the return side in your attic the AC will be sucking in 100-120 degree attic air in the summer. And nice edit when you didn't put the seal back properly at 5:34 :)

[@mcbeezee2120]

Been using high efficiency filters for over a 15 years. Change them once a month. And I'm still on all my original HVAC equipment.

[@agenericyoutubehandle]

That's $3000-4500 over 15 years in filters. I feel like if you got ones closer to that merv 8ish area, you'd save about 75% of that, or the cost of a new hvac unit. The difference to air quality is pretty negligible unless you have a health condition that calls for it.

[@Tsnor150]

totally agree with you. Air quality in house is improved. With a quality high merv filter you get same airflow.

[@timdavis6088]

Unless your manufacturer designed your unit for high efficiency filters you've wasted a lot of money over those 15 years. You'll still need to clean your coils periodically to ensure efficiency. Have you looked at the entering side of your coil lately? Blindly changing them based solely on a timeframe doesn't equate to the filters are loaded and need to be changed. Do you have a static pressure drop measured across the filter? That's the only way to know for sure.

[@donaldhollingsworth3875]

Most Heat Pump HVAC systems only require a fiberglass air filter. Using a pleated or high MERV rated air filter will cause excessive wear & load & wear out your HVAC system quicker because of the more restricted air flow. I always replace my air filter every month.

[@user-rs7ve3ky3u]

I’m in Canada so I have heat and AC furnace. I never use higher than a merv 8 and anyone I ever tell this to says I’m crazy. Thank you for justifying reasoning 😉

[@whiskey_tango_foxtrot__]

How about thickness? In the HD, there are the typical 1 in think filters and then some 4 or 6 in thick. Obviously, you would need to modify filter box on HVAC.

[@sunshine3914]

Use whatever your unit specifications say.

[@sunshine3914]

If you run your AC daily & have indoor animals, you want to check the filter weekly. And after any home improvements.

[@gwenedwards4845]

My filter keeps getting sucked up in my unit. My unit looks like yours. When it does get sucked up, the only way that I know is water leaks out of the unit and on to the floor. I know I am using the right size filter and I am not using a cheap filter. Please help!

[@Alavashus]

how do you figure out the correct size for the unit, my builder had the wrong size in there when we bought the house. Literally only covered half the return. I measured with a tape measure and made my best guess, but want to get the actual size that fits it. The filter is on the unit btw.

[@JL-gs6wk]

I also want to know this answer. Thank you

[@DOLLS.HOBBIESFORCHRISTIANWOMEN]

Just changed ours (Filtrete Merv 8), at 5 weeks. Meant to get it changed at 4 weeks. It was very dirty. We no longer have a dog and a lot less carpet, but still pretty dirty at 5 weeks. It's important and surprising when you see just how much is on the filter. Definitely a plus to change it often. 👍

[@dougspitler3843]

Pleated filters clog much more quickly than fiberglass and hold less dirt. Fiberglass holds up to 3x the dirt and are difficult to clog. If you want to get less airflow and want your unit to use more power, definitely go with pleated. But I wouldn't use a MERV 1 anything. Go with the highest MERV fiberglass filter you can find. Furnace filters are there to keep the coil clean so it is efficient, not to filter the air you breathe. If you want to clean up your air, get rid of your pets, carpet and upholstered furniture, then buy room air cleaner for every room.

[@stephenfarrell6794]

I buy from Discount Filters. I use MERV 11 but thinking about going down to a 5 based on what the last tech told me he uses.

[@della160]

Can you make a video on how to change the screen on a sliding door please?

[@seanb2995]

You should go over FPR rather then MERV in the future sometime

[@TriggB44]

It looks like your unit is installed horizontally, I think mine is vertical, so should my filters always be pointing up or down??? My filter goes in horizontally from what I can remember. I have a 4 inch pleated filter that I think is a merv 8 so how often would u recommend changing it??? The dude that put it in said they could go as long as 6 months between changes, is this true???

[@Thejaweee]

The arrow points in the direction air moves through the system so just make sure the arrow is pointing at the furnace. Yes, we routinely tell people those filters average about 6 months but it really depends on system usage and how much debris is in the air circulating in your home. Someone whose system runs constantly will need to change the filter more frequently than someone whose system runs very little. Only way to know for sure is to measure pressure drop across the filter, but I don't expect the average homeowner to purchase a manometer so I recommend doing a visual test at the 4 month mark. Keep a new filter on hand and just compare the new one and the old one. If you take the filter out at 4 months and it still looks good run it longer and check again next month. You will start to get a feel for when your filter needs changed and be able to build a regular schedule off of it.

[@TriggB44]

@Thejaweee wow, thank u so much! I need to screenshot all those info so I'll have it. It is very much appreciated 🤘🎶🙂

[@jwhite4]

I understand that a higher MERV filter is going to provide MORE air resistance. That's probably the price to pay for more air filtration. The question though isn't is it MORE (it is), rather is it excessive? If it is, doesn't Filtrete and other companies know that? Why would they now be creating MERV 20 filters if "HVAC experts" say that anything about MERV 4 is too much? I'm sure filters were originally meant JUST to protect the HVAC equipment. But now with some tweaking (higher MERV filter), they can also provide air filtration for the homeowner. That's a great advantage. IMHO, certainly worth a little less flow because of a more restrictive filter. I sincerely doubt that any HVAC system built certainly this century was unaware of higher MERV filters, and will be unable to cope with them.

[@killedbycoconuts]

Use duct tape to seal your filter door after you change the filter. It's amazing how much efficiency is lost without a good seal. If you hear a whistle sound, tape it over.

[@josephwofford5090]

Don't wear outdoor shoes in the house. The biggest difference we have found is to run robovacs daily. Far less dust sitting in the house to be sucked into the returns.

[@majorburke9735]

I’m using a merv12 bc Home Depot stopped offering a mere 10. It captures smoke. And a lot of pollution idiots in my neighborhood like to fire 🔥 up their chimney, fire pits and tiki torches. They like to pretend they’re camping or at the beach. My unit is about 40-years old. I fixed it twice with the help of websites and KZbin videos.

[@dasfahrer8187]

Filters in the attic must be a regional thing. Every house I've owned or rented has had the filter(s) in the hallway(s). Never seen one in the attic.

[@markkempton4579]

Hallway must also be a regional thing? I've only seen them in the basement with the furnace.

[@dasfahrer8187]

@@markkempton4579 Probably so. Basements aren't a thing here.

[@markkempton4579]

@@dasfahrer8187 got it. Makes sense.

[@perriponders289]

Holy cow when I had cats after 3 to 4 weeks the filters were loaded with cat hair, then again my returns were down on floor level where the filters are.

[@hkgonra]

Never seen a disconnect on a furnace/air handler. Every one I’ve ever seen is just a standard 120v plug into an outlet near the unit.

[@HowToHomeDIY]

It can be that. I have even seen them be a light switch on the air handler.

[@majorburke9735]

I’m using a merv12 bc Home Depot stopped offering a mere 10. It captures smoke. And a lot of pollution idiots in my neighborhood like to fire 🔥 up their chimney, fire pits and tiki torches. They like to pretend they’re camping or at the beach. The online price savings seem to kick in when you buy a dozen filters. About a 28% savings. My unit is about 40-years old. I fixed it twice with the help of websites and KZbin videos. My bought my Maytag washer/dryer combo in 1994. I fixed those at least 8 times. You know, belts, switches, blower fan, valves…

[@johnb.6468]

You must be fun at parties

[@majorburke9735]

@@johnb.6468 Ah, you’re a burner. I know the type. They don’t care about other people. They want what they want. I never had a problem with smoke before. Now my eyes burn and my chest hurts for days if exposed to my neighbors burn. It’s so bad I cannot sleep. Four nights a week I cannot step outside or use my garage bc the smoke is so thick. That means I can never have my windows open at night bc the burn probability is 50/50, and he won’t warn me before he burns. I had to buy new windows bc my old windows allowed the smoke in the house. He doesn’t have parties; he just likes to burn. The neighbor won’t stop burning bc he likes the “ambiance”. The city won’t do anything bc “it’s legal”. How is it legal to smoke out one’s neighbors? It’s not Christian. Houses in the city are too close to have fires.

[@johnb.6468]

@@majorburke9735 I’m not reading all that. I hope you stay up late thinking about smoke.

[@majorburke9735]

@@johnb.6468 ok. 👌. Good luck with your short attention span.

[@johnb.6468]

@@majorburke9735 I’m going to have a bonfire this weekend. Good luck telling your neighbors what they can and cannot do on their own property chief.

[@dustyre1]

Most filters on the unit? Not in my experience. Homeowners gonna be aggravated when they break their disconnect or can't get it back in. Very unnecessary. The open door will cause the unit to be less efficient, trying to cool attic air or heat.

[@steveo601]

Putting ac units in an attic😆😆😆😆😆😆😆😆😆😆😆😆

[@TM_Stone]

Pretty much all the homes in DFW area are this way and many homes in the US. Millions.

[@willjackson716]

You can also take a cheap filter and spray it with hair spray. It will catch more stuff.😉👍

[@jek9911]

Flip the breaker to change the filter... Jesus.

[@jamesjennings3098]

Here is your "head scratcher" when you restrict the airflow your motor amperage drops, costs less to run your blower! Don't believe me, get your amp meter and test it!

[@alanpleiman3378]

Means less air flow so your unit's running longer to cool the house down.

[@Thejaweee]

Older PSC motors and ECM constant torque motors will see amperage reductions when airflow is reduced because the blower is no longer fully loaded and not providing the air volume it is supposed to. ECM constant volume will speed up or slow down to maintain a set air flow so they actually see amperage go up when airflow is restricted.

[@dougdiller2906]

I tried ordering in bulk, but too often the merchandise was damaged in transit.

[@HowToHomeDIY]

Interesting. I have never had that issue.

[@trustbuster23]

Use of your system is not remotely linear. In other words, you use it a lot in winter/summer and almost never in the shoulder seasons. To account for that, my rule is that I change the filter at the start of each season. In other words, once you start running the heat, change the filter. Same in summer, change it right after you flip on the AC for the first time. Then change it again in the middle of that heating or cooling season. My unit still circulates air around the house spring/fall but since it is barely running then, that is when you want the filters to be at their oldest. I run MERV 7 and, thanks to wildfires now have a couple of HEPA air purifiers that handle whatever the furnace filter can't catch. I used to run higher MERV, 1" filters when I didn't know any better, and my blower motor eventually died a year or two earlier than it probably would have otherwise. I still got a pretty long service life out of the unit, but that mistake probably did shorten its life by a season or two. If you want to run a higher MERV filter, the HVAC tech has to account for that when the unit is designed/installed. You can normally retrofit a THICKER filter to give you the same airflow, but it requires duct work. Don't stick a high MERV, 1" filter into a system that was never designed for it, you'll waste energy and reduce the service life of the unit.

[@erwinhildenbrand3010]

Where is your condensation drain?

[@gilbertlopez8285]

I maintained my old construction trade college professor home and rentals. The last home I maintained for him for approximately 20 years the person who installed the air/heater unit wrote the dimensions of filter inside were the filter was installed. When they were moving out of the house I helped cleaning the house top to bottom. The air intake was a little dirty so removed the intake cover 📔. To my surprise there was a lot of construction debris laying all over the intake houseing (nails, straps, electrical wire, large pieces of wood, rocks and who knows what else.) I climbed into the the chamber to remove the debris from in the chamber intake I happened to look up were the filter was located and to my surprise a piece of metal angle was in place making the area where the filter fit smaller by at least 4 inches in length. Let let air to bypass the filter. I always wondered why the filter was so clean when I changed it every 6 months. Really never needed to be replaced as it was always so clean. When they purchased the home new from the bulider he gave them a two year supply of air filters to change every 4 months. They had a large unit downstairs and a smaller unit upstairs yet they had the same same size filter 🤔. The upstairs filter was the right size so they must have gotten a deal on air filters. This was during one of the houseing slowdowns so the builder was offering all kinds of incentives. He must have had a lot of angle iron so he had his workers cut it to length making it fit the smaller filters. Go figure.

[@FredD63]

Use a Merv5 this is what I have used for years and it’s what I recommend to all my HVAC customers I generally change filters every 2 months … most air handlers here in Michigan are located in a basement or main floor hallway … 🇺🇸👊🏼👊🏼🔨🪚