4" vs. 1" Filter
#1
05-31-20, 12:29 PM
4" vs. 1" Filter
I hear that the recommended AC filter is a good 1" filter and change monthly. I have a 4" box and am considering building a 3" spacer to put in the filter box and use a 1" filter instead of my 4" filter. Comments?
#3
05-31-20, 03:18 PM
Group Moderator
CasualJoe
voted this post useful.
#4
05-31-20, 03:26 PM
Member
4” is superior to a 1” filter.
Airflow can be reduced with thinner filters and cause equipment problems if you use a high MERV rated filter.
Airflow can be reduced with thinner filters and cause equipment problems if you use a high MERV rated filter.
#5
05-31-20, 04:28 PM
Member
4” is superior to a 1” filter.
So goes the big issue, home HVAC systems run for minutes per hour, how are you going to filter out imputities when the system has limited run time!
#6
05-31-20, 04:57 PM
Member
To be honest with you, the main purpose of the air filter within the hvac system is not to act as an air cleaner for the home. It’s to keep dust and debris out of the air handler.
Of course you can design it to do so, however the overwhelming majority are not.
The only way you can get constant filtration to maybe make a difference is to continuously run the blower, but a negative byproduct of that is it can raise the indoor humidity by re-evaporating moisture off the coil after the compressor shuts off.
The 1” high MERV filters that make claims of filtering out allergens and germs kill airflow tkk on the point the equipment performance can be affected, or even be damaged.
Of course you can design it to do so, however the overwhelming majority are not.
The only way you can get constant filtration to maybe make a difference is to continuously run the blower, but a negative byproduct of that is it can raise the indoor humidity by re-evaporating moisture off the coil after the compressor shuts off.
The 1” high MERV filters that make claims of filtering out allergens and germs kill airflow tkk on the point the equipment performance can be affected, or even be damaged.
#7
05-31-20, 10:50 PM
Member
or even be damaged
Not any different than changing that air filter on your car engine, got to take some responsibility to change them when they get dirty!
#8
06-01-20, 03:03 AM
The only difference between a Merv 11 one inch and a 4 inch is the square inches of filtering material.
As the filter is used it starts to clog up since there is more filter area with a 4 inch you have to replace it less often.
I would also think that a new 4 inch would have less resistance to air flow than a one inch because the pleats are larger but I have never measured this so it is just an opinion.
So I do not know where you heard that a 1 inch is better than a 4 inch but I would disagree with this.
I have had both and the 4 inch does a better job but this is on different furnaces so it may not be due to just the filter.
As the filter is used it starts to clog up since there is more filter area with a 4 inch you have to replace it less often.
I would also think that a new 4 inch would have less resistance to air flow than a one inch because the pleats are larger but I have never measured this so it is just an opinion.
So I do not know where you heard that a 1 inch is better than a 4 inch but I would disagree with this.
I have had both and the 4 inch does a better job but this is on different furnaces so it may not be due to just the filter.
#9
06-01-20, 05:39 PM
Group Moderator
to imply that the filter itself is going to cause problems is a bit of a reach.
Yes.... a clogged filter can cause the same problem but hopefully that is only a temporary issue..... not like running hi merv filters all the time.
