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Heat pump filtration options

forcedexposure | Posted in General Questions on
Good morning folks,

I was scheduled to have heat pumps installed in my house back in March, but put the project on hold because of the pandemic. My house is located in the county in Massachusetts which is seeing the highest number of cases and mortalities. It’s a very sad situation.

But I’m looking to bring the project back to life. Now, as I work on getting funding in place (thank you, DOER!), my awesome HVAC sales rep has brought to my attention a “Coronavirus Special” on Mitsubishi heat pump filtration systems. It’s a buy-two-get-one-free deal. 

The quoted cost for the IWave Air filtration is $500 per unit. I’m getting three heat pumps, so with the “Coronavirus Special” pricing deal, I will pay $1000 for  IWave Air installed on each of the three units.

My partner has spring pollen seasonal allergies and I have fall ragweed allergies. Our allergies can be pretty severe.

Will an added IWave filtration system affect the efficiency of the units?
Is the standard filter that comes with our units good enough for seasonal allergies?

The other option is for a UV light filter system, which sounds like it might be what the  President was talking about when he asked everyone to drink bleach. Is it correct that the UV light filter will kill viruses?

Here’s a list of what I’m having installed, with all line sets routed inside the house, as opposed to on the exterior. It’s three heat pumps, installed 1-to-1 with an outdoor unit for each.

Install Mitsubishi three single zone system

MUFZ-KJ09NAHZ-U1 Outdoor Unit 1.00
MUFZ-KJ09NAHZ-U1 HS-KJ09 Upgrade to MFZ-KJ09NA Floor Mount Unit 1.00
MFZ-KJ09NA DUI-097-150
MUZ-FH06NA Outdoor Unit 1.00
MUZ-FH06NA HS-FH06 Upgrade of MSZ- FH06NA Indoor Unit 
FH-Series MUZ-FH06NAH outdoor unit 1.00
MUZ-FH06NA HS-FH06 Upgrade of MSZ- FH06NA Indoor Unit 1.00

Not that it relates to the question about the filtration system, but I have had a Manual J done and have attached that here because I know how passionate you good folks are about your beloved load calculations! 

Thanks so much for your insight.

Best Wishes, Kris

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  1. Expert Member
    Akos | | #1

    For allergy, these type of ionization purifiers don't make any difference. My mini split came with a system similar built in and it does squat for my ragweed allergy.

    What works is getting the house air sealed and installing a high efficiency filter. In my case this is a MERV13 filter box on the ERV, but could be a stand alone filter.

    Getting the house tight is critical as any air leaks bring pollen with them, more air leaks the more filtering capacity you need.

    With the filter and unbalancing my ERV to slightly pressurize the house during allergy season (it is important to only do this during mild weather) pretty much keeps all symptoms at bay.

    1. forcedexposure | | #2

      Thanks! I’ll skip the additional filtration system.

      1. Expert Member
        Dana Dorsett | | #4

        A MERV 13 or higher on an HRV with low-speed constant recirculation would do a heluva lot more for removing aerosolized virus laden droplets than anything you could do with a cycling on/off mini-split.

        A room air filter with a HEPA filter does a lot too.

        When there is only a minimal heating or cooling load a filter in the head will do next to nothing unless you set the blower to run continuously. Otherwise it will just cycle on/off ( a lot, I'm guessing.)

        Those are a LOT of half ton & 3/4 ton ductless heads going on to the multi-split- are you sure they're all called for? Consolidating some into duct cassette zones would allow many more filtration options, and can get around the head-oversizing problem too. A half-ton Mitsubishi head on an MXZ compressor puts out a LOT more heat & coolth than the individual room loads of bedrooms & bathrooms call for. The SEZ-KD09 or -KD12 ducted cassette would usually handle 3-4 bedroom loads. A single -KD15 could handle either your entire second floor load (with margin), and a single KD18 could handle the entire first floor (with margin).\M_SEZ-KD15NA4_For_MXZ_MULTI-ZONE_SYSTEMS_Submittal.pdf\M_SEZ-KD18NA4_For_MXZ_MULTI-ZONE_SYSTEMS_Submittal.pdf

        Not knowing the layout and the routing/mounting constraints it's not clear how easy retrofitting ducted cassettes would be, but a right-sized ducted cassette that's running constantly at low speed should be more efficient and comfortable than a 2x (or more) oversized high wall or floor unit that's destined to cycle on an MXZ compressor.

  2. SJT3 | | #3

    Hi Kris, how are your new systems? It looks like you had the KJ heads installed on FH outdoor units? I didn't realize that was an option instead of using the specific KJ outdoor units - which are rated for much more heating/cooling than I will need. What did you end up with?

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