Residential Air Filters
- Thread starter Soft Cars
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Correct.
Not necessarily but it does put a strain on the system because it can't pull as much air across. We had an all-new HVAC system installed in October and they told us the most restrictive one they recommend to use are the orange Filtrete ones which are like MERV 10 but to make sure to change it every 2-3 months.
Not necessarily but it does put a strain on the system because it can't pull as much air across. We had an all-new HVAC system installed in October and they told us the most restrictive one they recommend to use are the orange Filtrete ones which are like MERV 10 but to make sure to change it every 2-3 months.
I run Merv 12 filters my filter flow area is up sized from the units recommendation.
Go thicker and higher pleat count when possible.
Go thicker and higher pleat count when possible.
High Merv filters are to an HVAC system as these are to a respiratory system.
gear patrol
gear patrol
Yes. You'll save some pennies or nickels. However if you increase the area of filtered air then there may not be any increase in resistance.
You'll need a gauge to measure the difference in pressure drop to determine how relevant the pressure drop really is.
Your A/C guy is correct, it's there to protect the system from dust and dirt, not clean the air in your house. I use the cheapest pleated filter available at whatever store I'm buying from.
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There is a formula used to calculate size of return air grill. One for pleat another for fiberglas. You should install larger grill for pleated filters. Any restrictions in airflow will cause evaporator freeze up. My systems use 1” pleated Merv 13 filters in return grill. And 5” Merv 13 pleated in return ducts. Systems designed for this. I want evaporator coil clean for efficiency and reduces dust in homes.
Triple_Se7en
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Merv 8's for decades now. Natural Aire brand most years.
Merv 6 gets dust and pollen
Merv 8 adds dust mites and mold.
Anything past that your literally talking hospital grade - smoke, smog, etc.
https://www.airfiltersdelivered.com/blogs/helpful-tips/merv-mpr-fpr-ratings
Merv 8 adds dust mites and mold.
Anything past that your literally talking hospital grade - smoke, smog, etc.
https://www.airfiltersdelivered.com/blogs/helpful-tips/merv-mpr-fpr-ratings
I use a 4.6" thick merv11 on my air conditioner to keep the coil clean. Got air cleaning I use a home made corsi rosenthal filter made from a box fan and 4 merv 13 filters.
From what I've read most home air conditioner returns are undersized. They can't afford more restriction.
From what I've read most home air conditioner returns are undersized. They can't afford more restriction.
I’ve noticed, at least with Filtrete filters, the initial restriction tends to go down as you go up in MERV. Someone else had posted some data in this thread about it.
https://bobistheoilguy.com/forums/threads/hvac-filters.336380/
https://bobistheoilguy.com/forums/threads/hvac-filters.336380/
I use a MERV 4 or less. Over the years many HVAC techs have told me that a MERV 4 or less is the best for the highest airflow and not putting a strain on your blower motor. He did say that if you have pets you may want to go to around a MERV 8 or so...When I had my 20 year old Goodman replaced I was surprised how clean the blower motor cage was. And many of the filters I used over that time were the basic fiberglass type...a MERV of around 2... I would change them every other month...It has worked for me ..
If you have a ECM blower motor it should spin at the same RPM using the rock catchers some guys here prefer vs a higher MERV filter. A ECM motor will use more electricity to compensate for an airflow restriction, but it will still usually be more efficient than a split capacitor motor. The old split capacitor motors spin slower when restricted.
If you're having a new furnace installed, I highly recommend asking what air filter box they want to use and make sure they install something large like a Honeywell 20X25X4 as an example.
Last to note is in my experience, the higher MERV filters slows down the dust accumulation in the house. Look at the dust around your house. Rub a finger on top of your TV.... .
If you're having a new furnace installed, I highly recommend asking what air filter box they want to use and make sure they install something large like a Honeywell 20X25X4 as an example.
Last to note is in my experience, the higher MERV filters slows down the dust accumulation in the house. Look at the dust around your house. Rub a finger on top of your TV.... .
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Just from my experience, which is limited. First HVAC guy told me to buy the cheapest filter I can find, should be in the $1 range. Then, change it often, every 30 days.
But why? Because at the time my system was 17 years old, and short cycling on heat. I was using those expensive $8 filters (1" 16x25), THAT, the seller of the home told me to use at closing. Imagine, he cared that much, that he would mention that?
Anyway we got a new system in 2020. It came with a 4" MERV 13 filter. I got replacements, 4 for $121. I thought that was a lot. Today, amazon has them 4 for $225. That's quite a price increase in 2 1/2 years.
At any rate, the new furnace has a ECM motor. I think the mentality of using the cheapest filter so as to prolong the life of the blower, does not apply. That's when the old furnace is on its last legs with a PSC motor. jmoymmv
I used to use the highest rated 3M 1" I could find and very expensive, last 2 years I have been using these from Honeywell. 3" filter that fits in a 1" space. MERV 10 rating and with all the additional surface area I can run them for 6-8 months.
https://www.supplyhouse.com/Honeywell-Home-FC40R1102-14-x-14-Return-Grill-Media-Air-Filter
https://www.supplyhouse.com/Honeywell-Home-FC40R1102-14-x-14-Return-Grill-Media-Air-Filter
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