On Monday, February 4, 2019 at 8:12:25 PM UTC-5, ChairMan wrote:
Ed Pawlowski wrote:
For the first time in 53 years of owning homes, my new
house has a
furnace and uses filters. It takes a 1" filter.

I see prices can vary considerably but is a MERV 8 and
MERV 8
regardless of the brand? Should I use MERV 8 or MERV 11?
We have no
pets.
I see filters with MERV 11 rating from $9.95 ($7.45ea by a
dozen) to
$14.50. Any real difference if they have the same rating?

Discount filters seems cheapest.

As long as you replace frequently(max 30 days) my AC guy sez
it doesn't matter much. Just keep em clean

Why would anyone in a typical house replace a filter every 30 days?
Once a season, tops for me. I frequently go a couple seasons because
they are not dirty. If you live in a house with a bunch of pets
and/or other issues, even then I can't see 30 days.

Merv 13 vs 11, if the price is about the same, I'd get the better one.
But you also have to look at flow rate and be sure the higher efficiency
doesn't restrict the air flow too much. The higher Merv filters are 4"
thick with deep pleats, to increase surface area to keep pressure drop
acceptable.