Which Type of Air Filter is Best to Use?

Which air filter should I buy? The one with a metal retainer? Or one without it?

With metal retainer... 16 in. x 25 in. x 1 in. EZ Flow Metal Retainer Air Filter, Case of 12-10155.011625 at The Home Depot

Without metal retainer... 16 in. x 25 in. x 1 in. EZ Flow II No-Metal Air Filter, Case of 12-10055.011625 at The Home Depot

 

Well, personally I like this type...Rheem 16 in. x 25 in. x 1 in. Basic Household Pleated Air Filter (3-Pack)-64300.011625 at The Home Depot just an example.

If you change it regularly the metal mesh shouldn't be needed.

 

If you are going to buy cheap filters (those are) then the cheaper ones are probably the better buy. Neither of those will do much filtering.

 

Filters are a big seller in our store. Many people buy whatever their furnace installer tells them, which is usually the high priced premium filter. When and if they ask me what to buy I give them my standard "spiel"...

I ask if their furnace or A/C is new (within 7 years). That tells me that most likely air flow is unobstructed and the ducts are fairly clean. I then ask if they have a dust problem or allergies. If they answer no I suggest they go cheap, the blue fiberglass units at 89¢ ea. and check them at 30 day intervals and change no later than 60 days. I tell them these will filter out only large particulate and pet hair.




If they say they have a dust problem I point them to the typical pleated filter.





This will filter out most dust but not allergens. It will obstruct some air flow but its minimal. Change every 60 days or sooner.

If they tell me they have allergies I point them to the 3M Filtrete series starting at the low 400 MPR rating and work their way up to the 1500 MPR rating as needed to alleviate their problem. Again, check the filter monthly and change as needed.




I always tell them to never let them go to the 90 days as advertised by the manufacturers label.


edit...Those cheap blue fiberglass units...I've used them for years and never have they contributed to any malfunction of the furnace or its motor or components. I know others will say otherwise.

 

I never,never, never, suggest using those "ultra allergen" things. You may as well put a piece of plywood in there IMO.

I prefer the metal backed especially if the filter is furnace mouted & you might be prone to forgetting to change it. That's the filter I usually use in my own house for the A/C. The system was installed over 20 years ago & just this last summer I looked at the evap coil. Not dirty at all.

 

I agree with Grady. They should not be used unless the duct system was designed for such restrictive filters.

Basic pleated filters are what I always recommend for filter grills.

 

I'm with some of the others...

Furnace filters are to keep the ducts and system clean....not to be a whole house air cleaning system. Unless of course it was designed that way...and most aren't.

 

I agree with previous posters that the high end allergen filters are very air flow restictive, but for those with allergies it can be a God send to solve breathing problems. Don't dismiss them so quickly. The important thing to remember is to check them regularly and change them often. If you have allergies the cost of those filters are a lot easier to handle than the cost of a new air purifier system for most people.

 

To REALLY know when to change an air filter you need a differential pressure gauge. A nice Magnehelic is ideal but will cost upwards of $60. Dwyer Magnehelic Differential Pressure Gauge 2002 0 2 0 WC - Dwyer Magnehelic Differential Pressure Gauges from Davis Instruments

Or you can get this less-expensive model for $18. G99 Air Filter Gage

I have the less expensive model and I will be installing it in the next few days and see how it compares to the Magnehelic.

 

Restrictive air filters can cause a high external static pressure. High external static pressure can cause a shorter compressor life and an eccessive heat rise across a furnace. Adding a return air grill may be required when high static filters are desired.