Fishy all over, humidifier makes it worse

by Mike
(Pasadena)

Can't say it smells exactly like fish, but it's more like that than anything else I could describe. Not like mildew, or gas, or burn off of a normal dust collection on a furnace, etc.

We just had a new central ac unit installed, including new flex insulated ducts. The HVAC is a package on the roof, the ducts are in the attic. Only the ducts to the first floor were not replaced as there is no access. New return, etc. We added a humidifier.

Old system did not have any odor. New system, from day one, has a fishy odor that gets very strong with the humidifier on. It's still there slightly with the humidifier off (not sure if it's residual or what, as I have a very sensitive nose). It happens both upstairs and downstairs (two zones) with heat on or with cooling on. I do notice it is worse when the sun has been shining for hours on the unit (which is in full sun, so it can probably heat up).

Had installer come and check it, and on that day, couldn't get it to smell enough (didn't turn the humidistat up enough). He is going to come back again to tweak a few other things in the setup (adjust dampers, etc.).

I checked all the breakers and electrical I can find, and found no evidence of heat or smell specific to any one location. All breakers are cool and most are brand new, and there is no smell at all near the box (as it's not in an air conditioned space). It comes from all ducts that are blowing, so not local to one room, zone or duct.

I understand that the smell, when from electric, is from the formaldehyde in the insulation burning, so wondering if there was some residual formaldehyde on something in the central ac unit from manufacturing that didn't get cleaned off? (That’s of course making sure they don't discover that some part is overheating when they open it up?)

My guess is that some part of the package unit has formaldehyde on it, and it gets picked up by the humid air more easily so it smells stronger when it's turned on. I understand that for cleaning off this residue, there are specific cleaners, but also that a solution with lemon juice can neutralize it. Anyone think I'm barking up the wrong tree?

Dadan reply:

Hey, Mike

I don't know the answer to this question. Allow me to get back to you by Janu 30 – Sorry … A lot of thing is going on. If I have other question, I will post it here.

Dadan