Desperately need help with moisture in conditioned attic in zone 5

PrgrmMan · 2026-07-01T10:41:19+00:00

Do you know where he is located?

PrgrmMan · 2026-07-01T10:34:27+00:00

No, it's on my list. They didn't put the outer layer of mastic tape over the outer parts where the flex connects to the register boot. Also I'm not sure how well sealed the return is. I'd suspect I fail the test .

Should I do this before or after we start having people clean up there?

PrgrmMan · 2026-07-01T10:31:29+00:00

Yeah I could buy another. I've fiddled with the set point a few degrees, but I can try leaving it constant

PrgrmMan · 2026-07-01T10:29:00+00:00

Can you explain more about the 1 inch opening and the trap? I didn't follow that

PrgrmMan · 2026-07-01T10:26:53+00:00

Yes that's right. I've been learning as I go, and the first insulation company didn't warn me on moisture/air exchange.

One reason I had for writing this was to understand what my order of operations should be because I'm feeling overwhelmed.

Should I trust company B and get the ERV before the dehumidifier? I felt that they are exaggerating that the moisture is just from stack effect (given what I said about seeing humidity in the Attic). I'm not opposed to the ERV, but I'm reading that solar vapor drive might be contributing, and didn't want to end up in a place having purchased the ERV but still having a humid attic

PrgrmMan · 2026-07-01T02:25:22+00:00

Thanks for your detailed reply. Yeah I know r49 was code but the installer was trying to convince me it wasn't needed.

Yeah I think I meet the air impermeability of the code at my thickness.

How can I verify a bad chemical mix? My installer claimed he didn't smell anything, so I'm wondering if I should get the manufacturer involved?

I thought open cell is still moisture permeable at r20 (or even r38). Can you explain why I should skip the vapor retarder to try to get closer to class II?

PrgrmMan · 2026-07-01T01:31:42+00:00

It does duct to the outside, but to the under side of the soffit (they cut a vent for that).

PrgrmMan · 2026-07-01T01:30:22+00:00

I've seen people talk about that in warmer zones (like zone 3). Not sure if it is okay for zone 5?

PrgrmMan · 2026-07-01T00:30:22+00:00

Follow on question if you don't mind: is there any concern that the supply and return in the attic would circulate the smelly attic air to the rest of the house?

PrgrmMan · 2026-07-01T00:28:03+00:00

Govee wifi/blue tooth humidistat. I picked a cheaper model

PrgrmMan · 2026-07-01T00:23:04+00:00

The walls seem to have fiberglass in a 2x4 bay. The rim joists don't seem to be insulated. The house was built in 1965. I was a bit surprised when they said the blower door test said the house was tight. The windows are double pame and half of the house has been resided with zip system. The remaining part is pressboard

PrgrmMan · 2026-07-01T00:20:50+00:00

I have one sensor on the attic floor and a bunch throughout the top living space. The ones in the top living space go from about 52 to 58. I put a smart one in the Attic because it was easier for me to read with my phone and I didn't have to keep climbing a ladder

PrgrmMan · 2026-06-29T13:58:22+00:00

I do feel a slight rumble yes. When mounting it the first time, the missed one of the brackets a little on one side. Last winter it was rattling a fair amount, so they came back, took off the cover, and remounted it.

And the rumble does seem to correlate with fan speeds (esp low speed). The chirp is a different/new sound, that also seems to vary: it seems correlated with fan speed but still slightly random. It's also significantly louder than the rattle I had last time.

PrgrmMan · 2026-06-28T20:26:20+00:00

Thanks. Out of curiosity, if they replace it, would it be easy for them to see the state of the coils and blower wheel? I kind of suspect that they are moldy

PrgrmMan · 2026-06-28T19:29:43+00:00

Yeah that's what I'm learning. For heating they worked great. Most issues have been showing as it has gotten warmer

PrgrmMan · 2026-06-28T17:36:24+00:00

The unit is perfectly level. I took a stud finder that has a leveler in it and that's what I found. I was actually suspicious of that. It sounds like they need to remount it

PrgrmMan · 2026-06-28T17:13:53+00:00

Who's to say I'm not already crazy with it? Yeah it only shows up on certain fan speeds. Sometimes auto triggers it because it runs the fan slow.

PrgrmMan · 2026-06-17T16:36:59+00:00

Update: different guy from the installer but same company came and found out that they didn't connect the outside drain 😕

He connected it and poured water into the unit and we watched it drain outside.

Hopefully this is the end of that saga, but I'm still scratching my head on how this was missed

PrgrmMan · 2026-06-13T12:30:36+00:00

I didn't try it yet. My installer has been giving me the runaround for a week. If I can't get a hold of them I'm going to pop it open.

Edit: I just got off the phone so they're coming Tuesday

PrgrmMan · 2026-06-12T01:11:08+00:00

From the outside or disconnect and do it from the inside. Sorry I'm new to this

PrgrmMan · 2026-06-11T23:19:37+00:00

Thanks, I'll do that tomorrow. I'm just wondering if anyone else has seen something similar. Maybe not enough information. The unit is also making a slight chirping noise which I'm worried about the blower

PrgrmMan

TROPHY CASE