HVAC Filters 101 - Airflow Report: Are Expensive Filters Worth It?

Related videos:
1.) Static Pressure Part 1:

2.) Static Pressure Part 2 - Airflow:

3.) Sizing ductwork:

[cookingwanunknownchef]

Thanks for confirming it. I had nothing but problems with those expensive paper filters. It would freeze up the outside pipe and killed the starter capacitor sooner than usual. I replaced it with the cheapest green fiberglass filters, and my AC last forever now and my electric bills cost less too. I told people that AC is not an air filter system. I installed a couple of air filter units inside the house to filter indoor dusts... 😃

[Bigsistr]

My mind is blown. I had no idea and I really thought i was doing the best thing getting the more expensive filters. Im going to upgrade (to the cheaper filters lol) this weekend and I will report back! Thanks for making this educational video for us uninformed homeowners!

[eppyz]

If you live in a dusty area and use the spun glass filter im afraid i would need a tech in every year to clean the coils. That itself can be a restriction and added cost. So where would a good compromise be?

[llee]

This video only focus on static pressure drop but the reason for expensive filters is better clean the air. I was expecting more on the performance of air cleaning verses air obstruction and how frequent one should replace the filters before severe obstruction.

[patrickbullock]

My return used a 20x30x1 inch filter for the first floor. This return vent was positioned near the corner of the wall allowing the addition of another identical vent and filter on the adjacent wall. This addition theoretically reduced the static airflow resistance by 50%. What an improvement!

[Kenster-man]

Some of the fiberglass filters are way too see-thru/porous with super cheap construction.

A compromise could be the inexpensive basic pleated filter (MERV 8 equivalent) by Home Depot (HDX Brand). Use it and toss away every 30-60 days.

The see-thru fiberglass filters may stop hair but that’s it - won’t stop dust particles. Again I’m not suggesting getting a MERV 11/13 Allergen filter but a basic inexpensive pleated MERV 5-8 filter and change regularly.

[cheryljones]

Wow! I just went to Lowes last night to purchase a new air filter, before turning my central A/C on for the season.... I've actually been buying the 3M Filtrete 1500 regularly, for the past few years!
I didnt realize they will make your system "work harder"???

[TronixA]

In my case, I actually tried to find fiberglass filters for my AC system and could only find those pleated types. Can anyone recommend a place that can make custom-size (21.5" x 23.5" x 1") fiberglass filters by chance?

[porkrind]

I'm partial to the hog hair filters, which I use most of the year. Supposedly a merv 4 at best. However once the temp hits 90° it's back to the merv1 fiberglass filter.

[jabaho]

Great video! I am currently running basic filters and have air purifiers in my home and it seems to make them last longer than previously, so that may be a solution for people that are afraid of the condenser system getting dirty quickly. Also there is less particulate mater in the air verified by my air things monitor which verifies my findings.

[KSguitarmusic]

We have an older system that was never really designed to handle the extra sq. footage of an addition that went on the house many years ago. Having just had a tech here yesterday to troubleshoot why the system is struggling in this hot weather, he discovered that it was low on R22; however, he also highly suggested switching from the heavier, pleated filter to a fiberglass for better flow. The only thing is, it seems like I'd be sacrificing good MERV filtration (with a rating of 8 with the Filtrete - which is what I use) for the sake of the MERV 1 or 2 rating on the fiberglass that won't provide near as clean air. So I'm sort of stuck at this point. I wouldn't mind trying the fiberglass or poly if I can find one in the correct size (20x25x1) that might have at least MERV 4.

[danielesilvaggi]

Thank you for this information it was extremely helpful.

[gpm]

I've been using the fiberglass ez flow merv 1 for years, should I be using the poly? even though I have no idea who makes a poly one, and should I be worried about dust build up on my motor fan if I been using the EZ flow fiberglass merv 1?

[JoshOlsonPersonal]

Interesting, I have a fiberglass filter. That being said, the house gets dusty too quick. I think I'm going to try a Merv8 🤷

[feathara]

Made sense. Thank you for saving me money. Got some off ebay.

[Level-]

Will any fiberglass filter do? I see Merv 1, Merv 2, Merv…. Are they all created equal?

[davebean]

Is the 0.5 restriction a 50% restriction, 0.5% restriction or some other value? Or put another way, is the difference between a .16 restriction and a .63 restriction significant? Would a 1.0 be a total restriction?

Would we be better not filtering our AC at all and filtering with other room devices?

Thanks for the video.

[rickjames]

So would going from a 1 inch thick to a 4 or 5 inch thick filter increase airflow to my registers on the far side of my house?

[frankg]

Are the permanent hydrostatic filters effective and efficient?

[SignorLuigi]

My house has 4 returns. Each has a filter. That is a whole lot more surface area than one 16x25 filter. The static drop you measured would be a lot higher like mine because my return system is moving the air thru much, MUCH more surface area. Project Farm measured the static drop of the Filtrete 1900 filter and it performed much better with regard to restricting air flow than you measured. Not sure why. But I do know that the Filtrete 1900 filter, because of its substantial number of pleats, has as much surface area as many 2" or 4" filters.