Aerostar 18x20x1 MERV 11 - 6 Count - Pleated HVAC, Furnace & Air Conditioner Filters - Removes Dust, Cold & Flu Germs, Lint, Mold, Pet Dander, Allergy-Causing Pollen, Smog & Smoke

Ok. So I am VERY particular on things like furnace filters. It drives my wife nuts how much I get focused on research for car waxes and furnace filters and even the chemical needed to clean the outdoor AC Condenser fins lol. I rarely post reviews but I wanted to make this very basic to cover what my wife says is important and what my reluctance-concern was when I submitted order and had hope many of the reviews were wrong on...First: The filters are NOT undersized. There are two things to look at on furnace filter sizes. The first thing is make sure you have the correct filter size to begin with! I can't tell you how many times I have talked to people (My brother in law owns a large HVAC company) at his company picnics etc that just flat out think there is no difference between a 20 3/8" filter and a 20" filter. You need to be sure direct from the manufacturer-that you have the exact sizing of the appropriate filter. Number two is they have two sizes listed in the product listing. This is true for 3rd party filter websites, Amazon, other retailers. The first is the "size of the filter" and then the "actual size of the filter". You need to realize that the manufacturer size is the "size of the filter" you need to match that up. What you need to also understand with these cardboard disposable filters is that the DEPTH measurement will not be the same. SO---The filter saying you need a 19 7/8" filter by 21 1/2" by 1" will fit the filter that is listed as such. What you will get delivered is one that is 19 7/8" by 21 1/2" by .75". That doesn't make it undersized lol. That's what you get. If you go to a big box retailer that's what they will have too. If you make sure the manufacturer size is what you got for the first two measurements, the 19 7/8" by 21 1/2",,,,,,the filter you get will be EXACTLY that. It is thinner at .75" though. THAT IS NORMAL. Measure one at big box stores, this is how it works. If it's too small, you ordered the wrong one in the first place/not shopping the right size.Second: I am thoroughly impressed with the top of the filter (where it has the cardboard going across in a diamond shape type pattern. I should have provided a picture of other competitors but this one is matching similar structure/strength as the big name brand ones. The ones I have been using (a diff brand than these) for the last 6 months, are definitely lesser quality and I can see that.Third: I change my filters every 60 days, have it written on my planner and a calendar reminder. These will do the trick, the quality is awesome and last just as long. The resistance for air flow appears to be spot on the merv rating in which they provide.Fourth: The packaging. These came in PERFECT condition. Keep in mind they are really thin chicken wire type skeleton as they all are. The way it was packed, there was no phsyical damage that will have any measurable impact on the effectiveness of this filter.I am really impressed and pleased. A great buy for the price. I have NO problem recommending these filters to people. I am sure for far more money and a very technical analysis I could come up with better options but again-----in this price range, and what you actually get delivered -I couldn't be happier. Great value for the money, for those that change them every month, there is no reason to spend 12-30 dollars a filter. Just get the correct merv rating for what you need, make sure the width and length are the RIGHT/Correct measurements. And you are set!

Cheaper and sturdier than other filter purchased before. I have a dog in the house and my wife suffers from pollen allergy. The filters arrived well packed and they are perfect in measurements. The previous filter warp over time this keep their sturdiness over the 3 months of usage. The air inside the house is better quality by switching from MARV 8 to MARV 11

I bought a home a few years ago that accepts these larger filters. Unfortunately, this size isn't generally carried in store (my personal experience anyway) as they usually sell the thinner (in width ) sizes.I did a cost comparison of options online and this was a great purchase.I have used two so far and they work well. I can't comment in filter quality because I have purchased many brands and never really noticed anything overly different when switching companies. I do try to opt for the one that filters more particles which tend to be more expensive.The package it arrived in was great. The box fit all of those filters perfectly and none were damaged.I will be buying again from this company.

The Aerostar MERV 11 Pleated Air Filter, AC Furnace Air Filter, 6 Pack is a good value and a decent filter. It does a good job of filtering the air, but they are slightly less rigid as some of the premium brands. Humidity can affect the longevity. I have used these for several years and recommend them. I moved down from the more expensive premium brands, and these Aerostar filters do get the job done. Because of their lower cost I tend to switch them out a little more often, but they will last 3 months without issue.High Merv values will generally last less than lower, I have found, as they tend to get clogged up with dust sooner allowed less air to pass through and cause the fan to be less efficient because of the increased back pressure. This is not this brands problem; it is all filters so be careful when selecting high Merv. I tried several different and found MERV11 is about a high as I would want to go. (for me) "but your milage may vary".

Love these filters… unusual size- easy to find on Amazon though! Sturdy, thick, great filter— we change every 30-45 days.

This 6-pack of MERV 11 filters nominal size 16 x 20 x 4 is a bargain: less expensive than name brands (obviously) but also the least expensive (on the web) for any of the other brands. There are some brands (especially on Amazon) that are Nominally 16 x 20 x 4 -- but the actual size is smaller than standard, and they will fit poorly. The actual (measured) size for a Nominal 16 x 20 x 4 filter should be 15 1/2 x 19 1/2 x 3 3/4.It is possible that a particular system was custom-sized for the smaller filter. So, if that describes your situation, then you can use the smaller filters sold on Amazon. But, those are not the standard size filters.

My heating and air-conditioning company said that the filters I was buying from the store were not a good quality filter. So these filters are higher quality and more efficient. The price buying these were $5.00 cheaper than the store price per each one. So now I will be getting my filters here and saving a lot of money in the long run.

I have a heat pump and it has odd filter measurements I ordered them on Amazon.ca they arrived within 2 days

Came in one package, very well made for a furnace filter. I liked the price and the amount of filters. Yes I would recommend the product.

proper size

Hard to find size filter at store at this price point .Great product .

Saved money and a trip to the store !