Cabin filter restricting air flow replaced.

[Bailey28]

The previous owner of my Dodge Charger installed a Bosch HEPA cabin air filter at some point. The filter looked fairly clean so I reinstalled it after inspection. I have noticed the fan speed needed to be cranked up on high to get acceptable air flow from the dash vents which got me thinking maybe there is a restriction somewhere.

I kept the fan on high and took a peek under the hood where the filter is located and noticed the cabin air filter was wrinkled and collapsed inward! I pulled the cabin air filter out and my airflow increased a ton.

I found a cheap paper Fram cabin air filter on closeout at AAP which flows great. No more HEPA filters for me.

 

[pudge]

i tend to think the Hepa filters are more restrictive by nature

 

[Hall]

Learned the same lesson with my furnace at home. I was using those thicker, ultra-filtering filters and it ended up tripping one of the limit switches. My HVAC told me just buy the $3-4 filters and replace them every 30 days, which I've been doing for years now.

 

[kschachn]

Learned the same lesson with my furnace at home. I was using those thicker, ultra-filtering filters and it ended up tripping one of the limit switches. My HVAC told me just buy the $3-4 filters and replace them every 30 days, which I've been doing for years now.

The notion that your HVAC filter is a whole-house air filter is a bit of a stretch for me too. It's there to protect the blower motor and A coil from clogging.

 

[rszappa1]

Learned the same lesson with my furnace at home. I was using those thicker, ultra-filtering filters and it ended up tripping one of the limit switches. My HVAC told me just buy the $3-4 filters and replace them every 30 days, which I've been doing for years now.

Yup....I use a MERV 5 or less filter on my HVAC...

 

[Geekhead]

The previous owner of my Dodge Charger installed a Bosch HEPA cabin air filter at some point. The filter looked fairly clean so I reinstalled it after inspection. I have noticed the fan speed needed to be cranked up on high to get acceptable air flow from the dash vents which got me thinking maybe there is a restriction somewhere.

I kept the fan on high and took a peek under the hood where the filter is located and noticed the cabin air filter was wrinkled and collapsed inward! I pulled the cabin air filter out and my airflow increased a ton.

I found a cheap paper Fram cabin air filter on closeout at AAP which flows great. No more HEPA filters for me.

Applies to furnace filters too

 

[Rand]

Yup....I use a MERV 5 or less filter on my HVAC...

Applies to furnace filters too

Definitely
I use the cheapest pleated filters not the fiberglass style in the furnace. The car filter is also just there to keep the junk out.. any pleated filter will be 99% the same.
Change every 60-90 days but I have wood floors and no pets.. The april filter I just tossed looked almost new.

I tried the bosch hepa a couple cars ago and it was half speed air at full blower.. full no go for me.

 

[johnmyster]

On your house, you can easily go to higher filtration (more restrictive) media if you cut the velocity across the media by either 1) increasing filter face area or 2) going to deeper pleats to effectively increase filter area. Increased filter area also holds more junk before becoming restrictive.

I went to a 4" deep pleat MERV-13 and have barely more restriction than the silly blue fiberglass. Yes, I have a differential pressure gauge installed to confirm and can verify with ammeter on blower motor. I also found out that glassflos filters are better than the "filterbuy" amazon equivalents.

Same would apply to auto filters, but yeah, the job of the filter is to keep the evaporator coil clean over the life of the car.

J

Post in thread 'Furnace Filter'

Mar 6, 2024

Your return air grill must be sized properly to use higher Merv filters. Too small and your evaporator will freeze up. I use Merv 13, my system was designed for them and no issue. Sams runs Filtrete on sale frequently, check online site. Amazon has good prices, sometimes they arrive damaged. Refund issued, they have improved shipping cartons, no damage lately.

In my case, the return grill houses the filter and is located in a place where I can't expand the ductwork. I got a "larger" and higher flowing filter (less pressure drop) by adapting the housing for a 4" deep pleat, as...

• johnmyster

 

[Thebigm]

The previous owner of my Dodge Charger installed a Bosch HEPA cabin air filter at some point. The filter looked fairly clean so I reinstalled it after inspection. I have noticed the fan speed needed to be cranked up on high to get acceptable air flow from the dash vents which got me thinking maybe there is a restriction somewhere.

I kept the fan on high and took a peek under the hood where the filter is located and noticed the cabin air filter was wrinkled and collapsed inward! I pulled the cabin air filter out and my airflow increased a ton.

I found a cheap paper Fram cabin air filter on closeout at AAP which flows great. No more HEPA filters for me.

I had the same experience