3 years ago we had a botched job of spray foam insulation and our attic. It resulted in a serious Health condition for myself. We recently had MLI and 2 solar attic fans installed. All of these things to try and lower our electric bills. Since the installation of the 2 solar attic fans there has been excess humidity downstairs in downstairs in our 2 story house and I’ve had symptoms similar to allergies running nose, fatigue, sore throat. I know that these are also symptoms of mold allergies.. Yes, I’ve been tested for covid and the flu, negative. Wanting to know if cutting the holes through the spray foam to install those solar attic fans has caused the problem? The company that installed solar fans said they’ve installed them in attics with spray foam before..help…desperate for my health….
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
You don't have to sacrifice historical elements of a house in the name of energy efficiency.
Featured Video
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
If your house isn't well air sealed the fans are sending out your conditioned air and drawing in hot and humid air from the outside from all the nooks and crannies of your house (rim joists, through the sheathing, attached garages, etc)
So it's not the holes per se - but it is the negative pressure caused by the fans.
There are a lot of articles detailing why these fans are a bad idea, but unfortunately they still get installed.
Any suggestions please..here is my reply to other guys question
MLI multilayer insulation. The nasa approved reflective stuff. We have spent $20,000 between foam snd this stuff and now humidity on first floor of home
Plus we just spent $10000 on a new heatpump,ac unit. I'm scared to contact company. We r having a air quality teat done next week to see uf it detects mold. If so, we got major problem. 1 with my disorder being heightened, 2 with like roof section replacement . I just cannot think about that.
What state are you in? I would try to find a contractor who is familiar with BPI or other whole house approach practices.
I can't give a whole answer to your questions but here are a few things you'll want to do:
Define your thermal/air barrier for your attic - I can't tell if it is the roof line (seems that way) or the attic floor. If it is the roofline - close all soffits, vents, and fan holes and bring the attic into the conditioned space with vents that lead from your main area.
Air seal major leakage points (which will be detected with a blower door test, or you can just have common weak areas seale)
If your air sealing makes the house too tight you'll need a fresh air exchange system, which can be something like an erv or a whole house humidifier with a fresh air intake added on.
We are in SW goergia. We already have an ERV. Foam Co removed wall batting insulation to fo spray foam. Did not ventilate and we were in the house. I was exposed to the VOCS therefore causing my MCS,EI. Company tried different things to try and fix i.e. removed floor insulation,installed ERV. Nothing worked I continued to get worse. Xpert came to evaluate foam found several faults. We sued ,got very little. My condition is lifelong. Along came MLI and solar fans. They first installed crawlspace
fan in attic,had to cut section of foam out over soffit. This 1 did no work. Lrft a big hole with no foam. hot humid air coming in. I stuff
some batten insulation in as best i could. They then installed 2 solar attic fans. Cutting thru plywood,shingles. We have not been able to make sure these fans are taking air out and not in. Not feelingvwell with covid.
The post above is correct, the attic fans are causing the humidity in your basement.
What is MLI? If you are trying to lower your electric bills remove the attic fans. They will cost you money, not save it.
MLI multilayer insulation. The nasa approved reflective stuff. We have spent $20,000 between foam snd this stuff and now humidity on first floor of home
Plus we just spent $10000 on a new heatpump,ac unit. I'm scared to contact company. We r having a air quality teat done next week to see uf it detects mold. If so, we got major problem. 1 with my disorder being heightened, 2 with like roof section replacement . I just cannot think about that.
... excess humidity downstairs in downstairs in our 2 story house ...
You do not state if your home has a basement or a crawl space. Nor do you state your geographic location. Both may matter.
Air infiltration is the possible source of the excess humidity - which is related to your geographic location. Further, if the home has a poorly air-sealed crawl space, your attic fans may be drawing humid air into the home from the crawl space.
The big picture matters when trying to determine a resolution to your problem.
We have a crawlspace
That's a start. Where is the home located?
Is the crawl space ground surface sealed by poly sheeting or by a thin concrete slab?
Is there water intrusion into the crawl space?
Is the crawl space ventilated, e.g. exhaust fans on one side, louvred vents on the other?
I have seen serious mold growth in barely ventilated damp crawl spaces. Depending on how make-up air gets into your home as the attic fans draw air out of the home, the air movement could be drawing humid air and mold spores out of the crawl space and up thru your home.
Crawlspace, plastic barriers on ground,Crawlspace vents around house are open. Located in Sw GA