Furnace Filter Rant!

[Sub Dude]

I have an 8 year old home with a Bryant Furnace that takes a EXPXXFIL0316 MERV13 16by 25 Filter. I change the filter every 6 months.

These filters are getting expensive. Every time I buy I need to just **** it up and hit the buy button.

I see them now for $50 to $100 each which is a big hum since a year ago.. Boy do they see you coming! The sizes are slightly different it seems for each maker which means finding a substitute more difficult.

I'm old enough to remember just stopping by the hardware and picking up a new 1" filter for a few bucks and you were good to go. Maybe its my age. No wait, I have a say here.

Any suggestions on a substitute or another filtration method?

Rant off. I'll be fine.

Sub

 

[mm08822]

Here is the difference in the $2 hardware store disposable filter.......anywhere from MERV1 to MERV7 vs MERV13.


Interesting how MERV13 has a useless spec for the 0.3 - 1.0 micron range. See what a MERV14 costs.

Anything you can do to reduce your filter cost will just be a cost elsewhere.

• Pre-filter - cheap disposable upstream of MERV 13/14.
• Measure pressure difference across MERV13/14 filter - replace/confirm when actually dirty vs. time alone.
• Electrostatic air cleaner.

I have mixed thoughts on duct cleaning........how much of the built-up dust fines continuously circulate throughout the system vs. just line the duct walls and remain fixed in place. Does the built-up dust fines create more surface area to trap air-borne fines passing through?

 

[bwringer]

When we had our heat pump replaced, they obviously ended up using much of the existing ducting and whatnot.

Anyway, we ended up with a ridiculously oddball and confusing filter size (20x20x5 nominal, which is a whole 'nuther pain in the *** because ours is actually slightly undersized (19⅝ x 19⅞ x 4⅜) to slide into the opening, but there are also filters on the market designated the same that are on dimension...) that's not available on the shelf anywhere.

Anyhoo, the best deal I've found consistently is to order them two or four at a time via Home Despot's website. They ship them to the store, they show up (eventually), and you go get them. So for my filters, I can get them for $30 each this way, and they're $50 - $75 each. I think shipping is a large component of the high cost if you order via Amazon and the like, because they're so bulky. Ship to store saves money if you're not in a hurry.

The other thing I've started doing is just pulling them out and taking a look at six months. I've never seen anything more than the barest whisper of discoloration at six months, so I just inspect every six months and change them annually now (at which point, they still look nearly new). Obviously, YMMV depending on your house, your environment, activities, house population, etc. We're just two people and a cat that doesn't move much in a not-very-large house that's not in a dusty environment.

If you have dogs, kids, a larger house, lots of dust, etc. then sticking with six months may make more sense for you.

Another consideration is that you normally should not change MERV levels much or at all; your system was designed around a specific level of flow, so going up or down a few MERV levels could change flow too much.

 

[American Locomotive]

Does your furnace list a maximum restriction on the intake? If so, I would probably get a gauge set up and measure the restriction at the filter and only replace it when necessary. You can get gauges like this: https://www.amazon.com/General-Media-Cleaner-Filter-Gauge/dp/B0195UXV7O?tag=atomicindus08-20

Also, if there's a standard filter that's larger and significantly cheaper - it's really not too hard to cut one down to size.

 

[4x4Pete]

Lennox is famous for the f'd up sizing. Deceptively made so that no other filter will fit, sizes like 17 5/8" x 27 3/16".

 

[Boogerman]

Coming from a farm environment, where we cleaned equipment air cleaners constantly, I do the same with my furnace filters.

I have 20x20x4" pleated filter in my furnace. As you said, expensive if you get a high merv filter. We have an extremely clean house (air tight construction, no pets, robotic vacuum often, cold air returns high on the walls). The last filter I replaced had been in 7 years. I take the filter out once or twice a year. Nearly no visible dust on it. I use a blow gun on the air line to thoroughly blow the dust off, from the back side, and then at an angle from the front and then back again. With little visible dust on the filter, a cloud of fine dust comes out that can be seen in the sun outside.
I occasionally replace the filter if it starts looking worn, discolored, warped, etc.

 

[squirrel17]

My furnace called for X6670 Lennox filters (16x25x5) and i got tired of the prices and through some research I found recommendations to use cheapest filters you could find so the blower doesn't have to work as hard. So what i did was got the cheap (16x25x1) filter for approx 4$ and made a 2x4 spacer (16x25x4) and together they fill the space. I replace filter first of the month and been doing this for the last 4 or so years. your situation might not be as simple but I'm sure you can figure out something similar.

 

[BrandonV]

Does your furnace list a maximum restriction on the intake? If so, I would probably get a gauge set up and measure the restriction at the filter and only replace it when necessary. You can get gauges like this: https://www.amazon.com/General-Media-Cleaner-Filter-Gauge/dp/B0195UXV7O?tag=atomicindus08-20

Also, if there's a standard filter that's larger and significantly cheaper - it's really not too hard to cut one down to size.

This. If you have the space install a Dwyer Magnehelic or similar and monitor the static pressure drop.

I also am a big fan of using the Honeywell deep filters which fit in boxes that only normally accept a 1" filter.

 

[Sub Dude]

Thanks for all the suggestions folks.
WE have an 8 year old home. We lost our dog Charlie less than a week ago so its just my wife and I and a cat that doesn't shed much. We do live in the country but we aren't dragging a lot of dirt into the house.
You got me thinking about just vacuuming the existing filter and maybe blow it off a little with some compressed air. In other words reuse and use fewer filters.
I'll keep looking around.
Sub

 

[zendriver]

The size means nothing as the “nominal size y”ou need to figure out the actual size which is usually on each filter

You can order no names off of eBay as long as you verify the actual size

 

[Bert_]

I just run cheap 1" filters. Keeps the big chunks out

 

[bonneyman]

Your HVAC guy - if he's worth his salt - can get odd-sized filters for you. Or he should be able to fabricate a spacer slot out of sheet metal to accommodate an odd sized filter track. Up or down. An inch either way is not going to kill you, but will allow you to put commercially available sizes in your unit.

Worst comes to worse there's filter manufacturers in most every town that can fab odd sizes filters for you. You may have to buy a dozen to get the price reasonable, but they do good work.

 

[hobie18]

Had to switch to simple one inch filters. The furnace would eventially stop. Then after a reset period, work again. Filter restriction was the issue.
Yes, filter prices have gone through the roof

 

[Jackfre]

Look up HVAC suppliers in your area. With on-line sales most branch mags will be happy to show a sale rather than having it go on-line. Buy a full box of whatever qty there is. When we bought our house a couple years ago we had a MERV 12 in the furnace and the unit short cycled like crazy over the first winter I paid attention to run times. I think we. Are all the way down to an 8 but the unit doesn’t cycle on limit. It is not the “filter is the cause of shut downs” It is the high limit of the furnace preventing over temp of the HX.

 

[brewchief]

We install a merv 13 filter on nearly every furnace we install, if replaced as needed(typically 6 months to a year)we see A/C coils that don't need to be cleaned, blower wheels that are still clean after 20 years and we also see far fewer failures of the expensive to replace ECM blower motors.

It is common for us to remove a furnce with a quality media filter that's 20 plus years old that still looks like new in the blower compartment.

I do not recommend using the high merv rated 1" filters, the basic pleated filter is the go to if all you can fit is a 1" filter.

 

[Ing3018]

I use 16 x 25 filters in a 4" depth; MERV 8 rating. I order a case at a time from Amazon.
I used 1" thick filters for a long time and tried higher MERV ratings but they pull the CFM down too low too quickly. My furnace (also a Bryant) can display the air flow and pressure values to give me data on when to change filters.

 

[hobie18]

Look up HVAC suppliers in your area. With on-line sales most branch mags will be happy to show a sale rather than having it go on-line. Buy a full box of whatever qty there is. When we bought our house a couple years ago we had a MERV 12 in the furnace and the unit short cycled like crazy over the first winter I paid attention to run times. I think we. Are all the way down to an 8 but the unit doesn’t cycle on limit. It is not the “filter is the cause of shut downs” It is the high limit of the furnace preventing over temp of the HX.

Yep lower airflow. Temp sensor. Etc. High merv would be nice, but the unit cannot gandle it

 

[Crazyjake8493]

I just run cheap 1" filters from Ace Hardware, $5 a piece. Change it once a month during heating season. Cheap insurance and it does the job.

 

[pbon]

My house has 2 AC systems and both use 20x20x5. I buy 6 at a time, Merv 11. I shop around and lady order I paid $27.50 each. Heat is radiant floor and radiator. Outside air fans are connected to each AC, but use washable filters though they are supposed to be replaced annually. Those cost about $10 each and there are 2 in each unit. I don’t complain about the cost.

 

[Hilltopmasonry]

I just run cheap 1" filters from Ace Hardware, $5 a piece. Change it once a month during heating season. Cheap insurance and it does the job.

There really is no reason for anything else

 

[PoorUB]

There really is no reason for anything else

Convince.
I have an Air Bear filter in my system. 20x25x5 if I remember correctly, but in my little rambler, and just the two of us a filter will last at least a year, or longer. I don't mind paying for a $40 filter and ignore it for a year.

 

[pbon]

Seems like there is more to the equation than simply saying the cheapest filter you can make fit is the best choice for everyone.

What size is the filter? Bigger and thicker means more surface area. How big is the house? Is your system high speed small duct or normal size? Do you have contaminants in your area such as pollen? Is your house dusty? Do you have allergies? Do you have pets? Do you smoke? How often is your house cleaned?

Where I struggle is whether to buy Merv 9, 11 or 13. The higher the number the greater the restriction. I have been using Merv 11 and the techs who have worked on the system think it’s a good choice. We have 2 systems and both are high speed small duct — old house with a lot of fine details and one system blowing from the attic down into the second floor and another in the basement blowing up into the first floor fit best and the higher speed smaller ducts also fit better.

 

[txvwnut]

K&N makes washable HVAC filters. I have a couple, when one comes out to wash the other goes in.

 

[nadogail]

I buy my filters from Amazon, they get delivered to my door at a very competitive price.

 

[Zrsnopro97]

Anyone tried the washable/reusable filters like this? We run a couple humidifiers during the winter and it's insane how fast they will clog my furnace filters up. We have hard/well water which is probably the main cause of this, all of the minerals and calcium in the air turn to a white powder/dust and get sucked into the filter. I'm talking about filter changes every 3-4 weeks or so.. and thats with a cheap low MERV rating filter.

 

[nh_yota]

If your system takes 1" filters then stick to the cheapest ones you can find because anything fancier will clog up very quickly.

 

[fitter30]

Generalaire and dwyer mark 25 both make filter gages. Most filter are good to 1" pressure drop but the filter manufacturer can give you info.

 

[Sub Dude]

I did some measurement and found that Filtrate makes a nice filter that would be a slide in. I installed it today. I bought a pack of two for around $45 dollars and that seems reasonable. Home Depot and Lowes also have a large selection of filters.

I read a little about MERV ratings and I went from a 13 to a 11 rating in the new filter.

Thanks for all the ideas.

Sub Dude

 

[Jeepster04]

I've ordered some from ol Dale Jr. I'm sure the price has went up, but it was $65 shipped for 4 filters back in May of 2024.

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[Dakotadadv8]

Replace my furnace filter every month IMHO cheap insurance. Buy the good stuff. Same as oil changes change every year or 3000 miles whichever comes first, regardless what others say, cheap insurance.