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  1. #1
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    High (.2) pressure drop across Aprilaire 410 filter

    Hello,

    I have an upflow furnace with variable speed motor running at 800CFM.
    The furnace pulls from the bottom using a return box.
    The filter housing is Aprilaire 2410 and it sits between the furnace and the return box.
    The filter media is Aprilaire 410.

    I measured the pressure drop across a brand new filter and it measured 0.2" w.c.
    The two probes were one right before the filter, and the other right after the filter in the blower housing.

    Aprilaire specs show .07" pressure drop from 800CFM, so I'm very confused.
    https://www.alpinehomeair.com/relate...et%2003.10.pdf

    I couldn't care less about the MERV rating, so I am wondering if there are any ultra low pressure drop filters available for the Aprilaire 2410 housing?

  2. #2
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    Mar 2013
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    Billington Heights, NY
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    how do you know you're moving only 800 cfm?
    This forum requires that you wait 20 seconds between posts. Please try again in 50 seconds.

    Experience - knowing when to get the hell out of the way and plug your ears. "Don't be a sissy. Turn it on!"

    Pecmsg - "NEST should only be used with 3-M filters to guarantee total destruction of the equipment!"

    Poodle Head Mikey - "the world is well populated with the unknowing and the uncaring and the stupid."

  3. #3
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    Thread Starter
    I'm relying on the blower to do the right thing since its variable speed, but maybe thats too hopeful.
    The furnace has an LED screen that shows the current CFM.

    The furnace is Rheem R96V 70K BTU with a 1/2 HP ECM motor. Max allowed static is 1", and max CFM is 1050.
    http://cdn.globalimageserver.com/fet...e-7209ecad93a8

    But even if its pushing for some reason max CFM at 1050CFM, the pressure drop should be about .1"?

  4. #4
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    Well, you can have 800 CFM at 1.5 and you can have 800 CFM .5 also.

    If your ducts are too small, the unit may be pushing as hard as it can just to maintain 800 CFM. Trying to force air through the ducts causes the pressure to rise.

    Perhaps you need an air professional on site to evaluate your duct system. .2 though a filter isnt horrible.
    This forum requires that you wait 20 seconds between posts. Please try again in 50 seconds.

    Experience - knowing when to get the hell out of the way and plug your ears. "Don't be a sissy. Turn it on!"

    Pecmsg - "NEST should only be used with 3-M filters to guarantee total destruction of the equipment!"

    Poodle Head Mikey - "the world is well populated with the unknowing and the uncaring and the stupid."

  5. #5
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    Thread Starter
    Interesting. So if the blower is trying to maintain 800CFM, but the ducts are restricting, the air velocity will be much higher, thus the pressure drop through the filter will be higher?

  6. #6
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    yes. the air will stack up against restrictions
    This forum requires that you wait 20 seconds between posts. Please try again in 50 seconds.

    Experience - knowing when to get the hell out of the way and plug your ears. "Don't be a sissy. Turn it on!"

    Pecmsg - "NEST should only be used with 3-M filters to guarantee total destruction of the equipment!"

    Poodle Head Mikey - "the world is well populated with the unknowing and the uncaring and the stupid."

  7. #7
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    What were teh actual static numbers.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  8. #8
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    Jun 2015
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    Thread Starter
    Return Pressure drop (800CFM):

    Total (with filter): 0.93"
    Supply: 0.58"
    Return: 0.35"
    Total (no filter): 0.75"
    Supply: 0.55"
    Return: 0.20"

    Those numbers are really sad!
    What does that mean for the actual FPM/CFM the blower is pushing?

    The coil is an A-style ADP coil, model ADP RE32636D http://www.adpnow.com/wp-content/upl...e-SG-HE-02.pdf
    I will need to measure the coil pressure drop, but will need to get longer tubes.

  9. #9
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    Thread Starter
    Please delete (dupe).

  10. #10
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    Coil PD show be low, since its a 3 ton and you only need to move 800 CFM through it.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

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