furnace filter size?

[ezover]

my current home system uses a 25x20x1 filter, the furnace is 13 years old, I do not know the current eff. rating for it.


my question is, can I use a thicker filter with out any problems? with the set up I have, opening the filter opening to accept a 5" would be easy.

 

[Done That]

It's not really the thickness that matters, it's the merv or efficiency rating. As long as you stay in the 8-10 range you should be fine. Too restrictive limits airflow and leads to heat exchanger damage.

The thickness is worthwhile in that you get more pleated surface area and therefore much longer intervals between changes.

 

[Kevin C]

At the same merv rating a thicker filter provides more media. Within reasonable limits, more media reduces restriction and reduces how fast restriction increases with loading.

To know for sure, use a manometer and test each sample.