Home HVAC filters

[Donald]

I have been using the cheapest pleated filter I can find, but was recently told by someone in the industry that even they are too restrictive and they recommend the el cheapo fiberglass filters. He claimed they filter well enough and are much less restrictive. Thoughts? It seems opinions vary, some pros recommend the cheap pleated filters and others recommend the fiberglass ones.

Aprilaire media housing with a 4" or 5" depth filter.

 

[Donald]

Yes, I have an Aprilaire system on the Carrier air handler in my Florida house. Since Covid, the price of a four-inch 410 replacement Aprilaire filter has gone from $37 to $54. At least they are good for 12 months or more in a clean home without pets and where windows are rarely opened.

I think they change mine 1X a year. The heat pumps get serviced 2X a year.

One 65 lb dog.

 

[Wireman1987]

Going to give the Amazon basics filters a chance internet sources say manufactured by a US company in us or mx facilities. I been using the project source filters from Lowe’s but no longer available.

The Amazon Basics MERV air filters are actually produced under private label. That means Amazon contracts an existing manufacturer (like Flanders/PrecisionAire, Filtrete, or a similar OEM) to make them, then sells them under the Amazon Basics brand.

• Several buyers have reported their Amazon Basics filters arrived with packaging that said “Made in USA”.
• Others mentioned theirs were “Made in Mexico.”
• Amazon doesn’t publish the exact OEM manufacturer, so the supplier can change depending on size, stock, and region.

 

[97prizm]

I have been using the cheapest pleated filter I can find, but was recently told by someone in the industry that even they are too restrictive and they recommend the el cheapo fiberglass filters. He claimed they filter well enough and are much less restrictive. Thoughts? It seems opinions vary, some pros recommend the cheap pleated filters and others recommend the fiberglass ones.

I worked apartment maintenance for a year and a half and all they used were the cheapo fiberglass filters. The ducts were matted with dust. My parents got 21 years out of their order furnace with 3m 3m Filtrete furnace filters.

 

[Mainia]

HVAC (furnace) filters were originally meant only to keep dust out of the heat exchanger and blower and later the AC condenser but have evolved into actual air cleaning devices. I had a long time HVAC guy tell me that using higher MERV filters is hard on the blower motor and obviously restricts flow volume which raises utility bills. Said to use the fiberglass filters to do the job as intended and if I want an air purifier filter get a stand alone unit in the living space which we've been doing for years. This might be old school thinking but there's no doubt the higher MERV filters restrict airflow. If you research it you'll find mentions that HVAC systems manufactured in the past 20 years should be able to handle MERV 13 filters without harm. Maybe so. Also you should be able to find what filter your unit is rated for if you have the literature that came with it or look it up online.

Our 7 year old 1600 sq ft house with 10 foot ceilings has a stupidly undersized 20x20x1 return filter so I only use the fiberglass filters to maximize flow. I tried a MERV 8 and it bowed significantly inward from the restriction so went back to fiberglass. Keep thinking about changing the filter box to a 20x20x2 or even a 20x20x4 filter to get more media just haven't done it.

If you were to change, the standard sizes are 16x25x4inch and 20x25x4 inch. Those 2 should be the standard and if the HVAC is worth anything, when they install to an average house it "should" be replace with the above. Skip the 2 inch setup. The original spec on my daughter's house (1950 st ft) was 16x25x4 but I forced the 20x25 and even the inspector caught the larger size the final.

 

[John105]

Jmoymmv. Using the cheapest filter or none at all is advice given when your furnace has a failing PSC motor. Modern furnaces have ECM motors and new installs get 4” filters typically.

There was once a time when cars didn’t have cabin air filters, and schools were built with asbestos. Sometimes things evolve but thinking does not. Likely 80% of the time the consequences are minimal.

 

[SammyChevelleTypeS3]

HVAC (furnace) filters were originally meant only to keep dust out of the heat exchanger and blower and later the AC condenser but have evolved into actual air cleaning devices. I had a long time HVAC guy tell me that using higher MERV filters is hard on the blower motor and obviously restricts flow volume which raises utility bills. Said to use the fiberglass filters to do the job as intended and if I want an air purifier filter get a stand alone unit in the living space which we've been doing for years. This might be old school thinking but there's no doubt the higher MERV filters restrict airflow. If you research it you'll find mentions that HVAC systems manufactured in the past 20 years should be able to handle MERV 13 filters without harm. Maybe so. Also you should be able to find what filter your unit is rated for if you have the literature that came with it or look it up online.

Our 7 year old 1600 sq ft house with 10 foot ceilings has a stupidly undersized 20x20x1 return filter so I only use the fiberglass filters to maximize flow. I tried a MERV 8 and it bowed significantly inward from the restriction so went back to fiberglass. Keep thinking about changing the filter box to a 20x20x2 or even a 20x20x4 filter to get more media just haven't done it.

Very similar here. J have been looking into adding a second return air box since my only one is 18x20 and is really too small. I was told by several hvac companies and a couple friends I know who do hvac work in another state to make sure to use those original blue thin ones.
Couple times I tried to run those pleated ones I could actually see the filter badly bowed in like it was having a hard. time. I just use the blue thin and replace every 30 to 40 days. I order a case or 12 every year around Nov since the current size is not easily found in stores.

 

[Wireman1987]

My main return takes a 20x25x1 master bedroom has a small return 14x14x1 I use merv 8-11 filters they been working for the last 4 yrs had my ac and air handler annual service it was quite clean.

 

[UncleDave]

3M for the 1" low end stuff. They have more pleats and flow better than most all per 1" and merv.

Almost everyone agrees a larger housing form factor is better.

The thicker the and bigger the better. Im using a 25x20x5 Merv 16 - hospital grade filtration and almost no pressure drop.

I also like my rental houses bryant EZ flex 26x6x6 folding filters. come folded up so easy to ship and store
Merv 13 on that works great.

 

[opus1]

...Couple times I tried to run those pleated ones I could actually see the filter badly bowed in like it was having a hard. time. I just use the blue thin and replace every 30 to 40 days. I order a case or 12 every year around Nov since the current size is not easily found in stores.

I had the same thing happen with my original system when I ran the AC. Combination of the blower running faster to move cold air upstairs and the steel bar that held the filter in place. On a side note, I hated the builder's installer for that; I'd have to open the furnace to change the filter and that bar crimped the filter's edges so even when using the cheap filters, they would bend inward a bit. I'd use the cheap blue filters and changed monthly during AC season, and used the stock of pleated filters during heating season until I depleted the stockpile.

Replaced the system a couple of years ago and I now have a sort of electrostatic filter - the media is similar to the cheap blue filters, but there's a plate that goes between the two layers that charges the media and apparently attracts more dust/dirt.

I also sprung for a UV light sanitizer. This was about a year before the "disease that shall not be mentioned" hit and I noticed several HVAC companies started using the light as a selling point once it did hit. I was a trend-setter and didn't even know it.

 

[dishdude]

Since starting this thread, I have switched to the fiberglass filters. I can hear there is a lot less restriction than with the cheapest pleated filter I tried. The fiberglass filters from Home Depot fit perfect, but are extremely thin. Any idea where a 1" fiberglass filter can be found? The HD ones aren't even 1/4".

 

[50yr Street Mech]

For a standard HVAC system, MERV 8 is suggested. Less restrictive on air flow, which will save you're blower motor. I have a POS Goodman HVAC system that came with the house. New construction. Cheapest junk on the market. Contractor grade garbage. BUT, easy to work on. The blower motor died within 5 yrs.,,running Merv 8 filters. I actually took the whole unit apart to get at that motor, and put an upgraded one in. Never worked on an HVAC system in my life, and I have no service contract. It was time consuming, but pretty easy to do. Hope it lasts a few more years until we move.

 

[Donald]

Aprilaire sells a media filter housing you install into the HVAC system and then you use an Aprilaire accordion type filter that ends up providing a 4" or 5" filter. It's the ultimate in HVAC air filtering. Replacement filters are $75.

 

[Donald]

For a standard HVAC system, MERV 8 is suggested. Less restrictive on air flow, which will save you're blower motor. I have a POS Goodman HVAC system that came with the house. New construction. Cheapest junk on the market. Contractor grade garbage. BUT, easy to work on. The blower motor died within 5 yrs.,,running Merv 8 filters. I actually took the whole unit apart to get at that motor, and put an upgraded one in. Never worked on an HVAC system in my life, and I have no service contract. It was time consuming, but pretty easy to do. Hope it lasts a few more years until we move.

Goodman is definitely builder grade and expected to last 6 to 8 years.

They are widely used by builders in DE when building the developments. I wonder how new homeowners feel after plunking down $500K on a new house and have the HVAC fail after 6 or 8 years. And then do you get another Goodman or pay 50% more for Trane?

Do they even offer an HVAC upgrade option? I know you cannot afford every upgrade option. Gotta choose based upon your budget. Assume wife goes for the kitchen upgrade option.

What about the roof. Are they getting the best shingles (short of designer)?

 

[97prizm]

Here is what I have been told....YMMV....
Air flow determines how much water is removed from the air in your home (assuming a properly sized and efficient AC system). If the air flow is too great, too much moisture is drawn off the coils and back into the air resulting in higher humidity.

Not enough air flow and the coils can freeze condensate and block the system. It's a balancing act.
The air flow is adjustable by setting the fan speed and by filter restriction.

Just keep in mind that it is crucial to keep dust and dirt off the coils so good filtration is important.
I'm just the messenger...don't shoot

Some older systems don't have coils that have a door to make them easy to clean. They can be a pain to get to.

 

[Mainia]

* 4 x 16" x 25"
* I change it at 18 months (might try 24 months) .... they are expensive filters and at 18 months, look good but a little grayish color.
Most people would change them after 12 months.

Initial gage readings would depend on-
number of people in house,
pets,
carpeting etc.
Initial gage reading also depends on duct sizes, and number of return lines.

I'm not in the business, only an excessive compulsive homeowner for 38 years.

The differential pressure gage I use is an acrylic (red dye) laboratory type made by Dwyer.
They also make a less expensive model for homeowners.
https://www.grainger.com/product/2T...p.ds&msclkid=feb190be9ac01af54fb0f7431963b4a5

https://www.amazon.com/Dwyer-25-Man...mark+ii+25,+0+in+wc+to+3+in+wc,aps,189&sr=8-1

 

[rszappa1]

Goodman is definitely builder grade and expected to last 6 to 8 years.

They are widely used by builders in DE when building the developments. I wonder how new homeowners feel after plunking down $500K on a new house and have the HVAC fail after 6 or 8 years. And then do you get another Goodman or pay 50% more for Trane?

Do they even offer an HVAC upgrade option? I know you cannot afford every upgrade option. Gotta choose based upon your budget. Assume wife goes for the kitchen upgrade option.

What about the roof. Are they getting the best shingles (short of designer)?

My Goodman lasted 19 years...both the gas furnace and the HVAC....

 

[UncleDave]

Aprilaire sells a media filter housing you install into the HVAC system and then you use an Aprilaire accordion type filter that ends up providing a 4" or 5" filter. It's the ultimate in HVAC air filtering. Replacement filters are $75.

These are nice as is the bryant ezflex

From everything Ive seen the lennox 6675 is the king of the hill though at 25x20x5 carbon impregnated merv 16.

 

[Wireman1987]

Amazon filters came shipped in a sturdy box free of damage they look on par with any others in their merv and price point. Still time left before needing any filter change

 

[RyanY]

The best choice depends on the return/filter location, according to my HVAC guy.

My return is high on the wall so it doesn't see much dog/cat hair. He recommended the cheapo green filters which last 3-6 mo before they are ready to be changed. At first I was skeptical (because more is better, right?) but when I cleaned my evaporator coil a year later it was mostly clean. Condenser coil is different because it lives under a tree, so it gets sprayed twice/year.