Filter never needs cleaning...

...because it doesn't catch anything.
My previous forced-air furnace was replaced in December. It had an electronic air cleaner that never captured any dust. I had that installed because my wife has allergies and the 1" standard original filter caught very little (thin film of gray after 6 mos.).
Now I have a new high efficiency Bryant with a 5" filter and after the recommended 6-month service interval I pulled the $30 filter...and it's spotless.

There are no gaps in the ducting between filter & blower. There is negative pressure on the return side & air can be felt passing through the filter. If I try to slide the filter out while running the blower will suck it back into place.

With the new variable-speed blower I've been leaving the fan ON 24/7 as recommended by the installer. It does seem more comfortable in the house but dust collects that much faster under the furniture.

I'm accustomed to my forced-air system properly keeping the temperature correct, but it doesn't clean the air at all. How normal is that?

 

Does not make sense, no house is that clean.

Over the years I've had them all, electronic, 5" high efficiency, and currently mid grade 1" filters and after 4 months they were all noticeably dirty.


Exactly what do you mean, because the blower is on your seeing more dust?

 

Yes. Now that the blower runs all the time I'm seeing greater amounts of dust.
It is building up quicker.

 

Where are your cold air returns located? For example, mine are located high on the wall - opposite the warm air floor ducts in most rooms except the kitchen and baths.

 

Downstairs they're low, upstairs they're high.