Merv furnace filter ratings

[alarmguy]

Get yourself a K&N hvac filter. Upside will outlast 40 filters. Downside, swift and predictable BITOG opprobrium.

https://www.knfilters.com/home-air-...oM3lsJx9YDnRFJTEqaH8gYatyhqdE26hoCBcoQAvD_BwE

Didnt know that they exist. But for me personally the downside is they have to be cleaned. I like disposable. I dont even like bagless vacuum cleaners!
It is a neat concept though, if it is all it is marketed to be just not for me. However I do see they have a 14x14 Merv 8 should I ever want to try as that is the size of the master BR filter. The site offers no airflow resistance that I can find either.

 

[Barkleymut]

i was using those allergy reduction pleated filters. My HVAC guy saw them and said "Do you sleep with your head under the blanket? Well that's what you're making your unit do." Ever since I use spun fiberglass and change every 30 days.

I use the fiberglass filters and after 6 months you can barely see any dust on them. Changing every 30 days seems way too often to me.

 

[LenZee]

I use the fiberglass filters and after 6 months you can barely see any dust on them. Changing every 30 days seems way too often to me.

A fiberglass filter is the equivalent of a counterfeit K&n oil filter made in someone's backyard in china.
Or as known in the hvac trade a "rock catcher".

 

[Racer4]

I buy pleated filters from Home Depot their house brand SPR *5 merv 6 change every 3 month blow them out about every 1 1/2 months with my air compressor.

 

[alarmguy]

I buy pleated filters from Home Depot their house brand SPR *5 merv 6 change every 3 month blow them out about every 1 1/2 months with my air compressor.

I currently have some of these, actually changed them just yesterday. For the price I dont think they can be beat and chances are many are in the same "class" at higher prices. It does seem like a great deal.

I took photos of the ones I changed out yesterday and also one other brand that is built more robust and sturdy at a slightly higher price that I think I am going to use once these HDX's are finished up. Our main filter is a 14x25 and I dont like the way the HDX bows in when the unit kicks on,, with that said that goes for a lot of filters so I am not knocking them.

I ordered some of the others (also have photos) they arrive on Monday but these are for the second smaller intake 14x14 cost is $6.50 each. I also ordered the 14x25 but two different sources, Walmart and Amazon the 14x25 right now is on sale at Amazon for $4.87 each. they come in 6 packs. The filter company is MOAJ

What I like about them is they have cardboard supports on both sides not just one side, meaning whenever I see "echo friendly design" I know it will be less robust *LOL*

I'll post more on this another time. Been in BITOG WAY, WAY too long today.

 

[jkasch]

Get yourself a K&N hvac filter. Upside will outlast 40 filters. Downside, swift and predictable BITOG opprobrium.

https://www.knfilters.com/home-air-...oM3lsJx9YDnRFJTEqaH8gYatyhqdE26hoCBcoQAvD_BwE

When I looked up mine, it had a California cancer and reproductive health warning. I mean I know it's crazy California, but what the heck?

 

[Rand]

Merv 12 here wouldn't run anything less, I like to use filters that actually filter.

There are many ways to solve airflow issues.

HVAC people want you to use cheap filters so they can sell you cleanings.

A cheap pleated filter is plenty to keep the crud out.
if you have allergies use a hepa air purifier.
merv 12 is too much for most older 1" thick installations where the filter is smaller. 16x20 etc.

 

[Revving2Redline]

3M Static Charged 8-10 merv

 

[97prizm]

i had Merv 10 last year.
Pretty much had to change it every week, or the air flow was reduced.
I DON'T have a clean house by any means and seldom vacuum.

Having the Daughter just pick me up some of those cheap fiberglass filters. Merv 4 ratings.

Thoughts other than better house cleaning?

Id look at having your ducts cleaned. I use the 3M Filtrete 2100 filters and those last 3-4 months without any problems.

 

[Mainia]

I gutted my OLD Honeywell Electronic filter that were the big deal back in the 70-80's. This allows a filter cavity of 16 x 25x 5. I use 16x25x4 MERV13 and "pre filter" with a blue fiberglass cheap filter slid in front of the MERV 13. This starts the "caking" process on that cheap filter, and I get double the life out of the MERV 13 for a couple of bucks. This works even with horrible 1960 ducting in a small 1949 rambler. Having a variable speed DC drive fan motor in a 97% American Standard/Trane helps too. I have no freezing A-coil or winter short cycling in the winter. It runs great with this setup.

 

[TumblrDucks]

Merv 13, with 90%+ filtration rate for <pm3.0 particles, the furnace becomes air purifier.

 

[Skippy722]

A cheap pleated filter is plenty to keep the crud out.
if you have allergies use a hepa air purifier.
merv 12 is too much for most older 1" thick installations where the filter is smaller. 16x20 etc.

The higher MERV 3M Filtrete filters have a lower pressure drop than their lower ones. I generally run like their MPR1500/MERV 12 in 14x20x1. Plugs up slower than the cheaper ones too.

 

[alarmguy]

When I looked up mine, it had a California cancer and reproductive health warning. I mean I know it's crazy California, but what the heck?

I think every product in your house has that warning, especially if the product contains any plastic

 

[tcp71]

Merv 11 changed 3 times per year

 

[alarmguy]

My AC installer advised using the lowest Merv that isn't one of those tangled-up fiberglass looking ones. I believe mine are Merv 8. He warned anything higher is undue strain on the blower motor.

It can also make the system less energy efficient and your house warmer if the filter restricts air to the evaporator.
What happens then with less air moving over the expansion valve sensor the expansion valve will not open as much due to the reduced airflow, for lack of a better words less cooling power to the evaporator.

The expansion valve adjust the amount of Freon moving through the coils in order to not cool the coils too much where they ice up. So less air flowing past, the sensor will reduce cooling power while the compressor runs all the time.

I use Merv 8 filters in both intakes.
On occasion, if the second smaller filter in the master bedroom was on sale for Merv 11I would sometimes get it in our last house, but we had four intakes in that house
In the current house, we have two so I keep it at 8s

I have my favorites because there are some really cheap 8s out there and I’m not sure how much they may restrict air flow

Someone in this very forum posted a pretty good site with a publish airflow resistance for the filters and it shows their Merv 8 have the least amount of resistance.

The builders heat and air company here actually use a pretty good low resistance, merv 4 or 5
One of the best fiberglass filters I have seen where it’s a full three-quarter inch thick instead of those thin ones however, I don’t use them and I actually posted one of the filters I just ordered on Amazon a number of posts before this one (post 25) I was impressed with their performance and the way they were built.
The company is MOJA

Also @factorytuned2012 posted a brand that I also was impressed with as they publish the resistance numbers and it looks good on their Merv 8s
This was the link he posted in another thread https://trufilter.com/

As far as cheap filters, Home Depot sells their own HDX brand. I tried them and actually have another one or two to go. They’re OK but for the same price, I can get much more robust filters and I don’t know. I just have this feeling they’re a little restrictive because they get sucked in with when the air-conditioning turns on.

 

[facility1]

consider a Merv 11 carbon infused filter, works well as I have a female friend that stops over, it helps reduce her cigar smoke smell.