Hey – I know this has been asked and answered before, just want to run what I’m doing to see if it makes sense.

I have a passive house retrofit in NYC – 2 stories, 1600 sq ft + a basement that is _mostly_ outside the passive house envelope.

About three weeks ago, the interior RH starting getting really bad – depending the device anywhere from 62-75% (yikes).

I have 4 standalone ERVs (zehnder comfortair 70s); a 2 zone LG VRF heat pump; 2 mini splits in the basement.

I mentioned that the basement is _mostly_ outside the envelope. The mechanical closet that holds the air handler is in the basement and inside the envelope, there is a gasketed door and a cold air return duct in the living room floor connected to it.

I figured from what I’ve read here the following:
the VRF is oversized
the ERVs are pulling in or creating humidity (less than would happen from a leaky house but still something)
running AC isn’t helping b/c VRF oversized and temps aren’t low enough even with the fan on low for the coil to remove that much heat.

So I did the following
– I removed the gasketed door to the basement
– I added a dehumidifier to the basement
– I’m running the minisplits in the basement on a constant temp of 72
– I’m running the fan on the 2 zone VRF system to circulate the air in the house

So I’ve kind of de passivized my passive house 🙂 

Here are my concerns:
— should I get the VRF looked at? I did try to run the the dry mode and AC before and like I said house was stuck with RH between 65-75. Could the VRF have an issue? (My guess is no) (I changed / cleaned all filters fwiw)
– Air quality – so far my monitors are reporting 0 pm2.5 / pm 10 and with teh current setup, the VOCs being reported are much lower too. 
– efficiency – is running two mini splits full time and occasionally running the main house A/c efficient (I run the A/c at night and maybe for an hour or two in the late afternoon, like 7-8, if I’m doing something active like cleaning or cooking)
– fan – does it matter how fast / slow I run the fan? How could I test this? 
– pressure – am I messing up with the pressure of my passive house by essentially leaving a door open all the time (the gasketed door to the air handler in the basement)
– Anything else I’m not considering? 

I might try to add a whole house dehumidifier but I’m kind of thinking that if a portable unit is doing the job for $400, I don’t need to invest in something far more complicated. (also my summer time electric is all solar (and the grid is 1:1 exchange and I overproduce) so increased efficiency has to be really high to justify a change.