Anyone running a media air cleaner at the furnace instead of returns?

[SZR48207]

I'm mulling over installing one of those on my central HVAC system in the attic. (gotta go measure to see if there's enough room to stick this next to the furnace, but between the duct plenums.

It's a 4 ton system, and currently has (3) 14"x30" return grates, each with a 1" 3M filter on it.

My understanding is that 4" deep plated filters have less pressure drop, MORE surface area, and would require replacement only once a year.

I guess the only concern I have is filter availability, as 4" deep plated are not common to find in home stores, and I could end up with a proprietary size that can only be bought from a company like AprilAire.

Any experiences?

 

[mk378]

The filter is always before the furnace for a good reason. The fan and heat exchanger will clog up with dust. High efficiency heat pump coils have narrow passages.

 

[tomcat27]

we have a filter on our furnace that uses 20 x 25 x 5. yes, the filters are a little pricey. $45 for two.

 

[Kestas]

I once made the mistake of buying these deep filters on price. I found the cheap ones have way fewer pleats..

 

[beanoil]

Filter in cold air return right before furnace is correct.
I change deep pleat filters every 6 months, and honestly don't think they would make it a year. YMMV.
Amazon has several vendors of filters in every size imaginable, I've seen 3 for 60 before.

 

[CR94]

Don't you still need at least cheap filters at return grates to keep the ductwork from filling with dirt? I've seen that happen.

 

[Snagglefoot]

Here's mine installed at the intake in the basement. It has an electrostatic element plus the wire backed paper element. The efficiency depends on the MERV rating. Mine is an 8 out of 12. An 8 is common. It lasts a year without difficulty, even with a dog and a cat in the house. Here are some shots.

 

[oldhp]

Best thing I ever did was get rid of the 1" filter and go with a 4" filter. Less pressure drop. I change mine every 6 months. Buy'em on line for better pricing.

 

[SZR48207]

Thanks for the pics, Snagglefoot.

 

[spackard]

Have one of the old Aprilaire, with combs I have to move over when I change the filter.
I bought a box of filters, keep them in a corner for several years, change 1/yr.
I didn't size the system, a professional company did when they installed the whole system. They did the real manual J calculations, so I assume they took into account the pressure drop of the filter.

 

[spk2000]

I have a 4 inch Honeywell Brand I buy once a year from Home Depot around $30Need to put it on a calendar alert so I don't forget but it usually still looks pretty decent so could probably go longer.

 

[UncleDave]

Yes- the only filter I run is at the furnace vs returns.

I run a Bryant EZ-Flex Merv 13.

They ship folded like an accordion.
You unfold them and pop plastic endcaps on and slide the assembly back in - a 3rd grader could do it in 5 min.

I buy them in boxes of two and run each a year.


UD

 

[alarmguy]

I use 4 Inch filters on my air return grills. We have 4 air returns on two units.
I prefer the grill filters as it also helps keep the return ducts clean.
Replace once a year.

In fact, just got my order this week.
I always order where the best price, I used another site for another size.
I always use merv 8 when possible, however sometimes merv 11 is found by better price. I actually prefer merv 8, less restriction.
I dont buy brand, only price matters to me. I paid less then $65 for 2.

I bought these here - Click, $61 for 2

They look like this, not Honeywell brand though - Click