Negative air pressure/Desperate for help

Hello, I have a very complex building science type of issue happening in my home. While I do have most of the answers, there are still some mysteries left to solve. Insulation was added to my attic in my modular home, plugging up the soffits for air flow. This has made my home extremely “tight” and without the ability to “breathe”. It has caused multiple appliances to be backdrafting, or pulling air in backwards, including my clothes dryer. Which has led to a vapor matter which carries with it the insulation in the attic that was left unsealed, as well as building materials. An ERV was gifted to me throughout this very difficult situation, yet that machine has not stopped this from occurring and I’m seeking help to put these mysterious occurrences to rest and move on to remidating the problem. Since the agency who added this insulation refuses to take responsibility, I also must obtain an individual who is willing and able to put all of this in writing to help me further along with this situation. This has been a two year on going nightmare, and I wish to bring it to a close as it has affected myself and family greatly, with one of my children becoming asthmatic. This vapor matter which carries with it the insulation and other materials has filled all carpeting in every single room, furniture, bedding, ect as they are all acting like sponges. This is not stopping and continues. Please help if you can, or if you have anyone you can refer me to I would certainly appreciate any and all resources. I have tried nearly everything over these past two years and am wanting nothing more than to move on with my life and put this horrendous nightmare behind me. Thank you.

Have these installed in the truss bays.
InsulationBaffle

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There is really not enough information here to give you any kind of definitive answer.

Blocked soffits would affect airflow in the attic only, and not air or make up air in the interior of the house. If they didn’t install baffles/soffit vents like in the picture in the post above, and they installed insulation over the soffit vents blocking them, they failed to do their job correctly.

One thing you may want to check is if you have a combustion air inlet/fresh air make-up duct in the attic that terminates near the furnace or water heater, they may have blocked it off with insulation.

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So, you need to know who to hire to troubleshoot and document this issue? Is that the big question?

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If you have ridge or other static vents in the attic at the top of the roof, blocking soffit vents will depressurize the attic due to stack effect, causing air to be sucked from the house. If there are other openings in the attic that communicate with the house, that’s where the air will come from, causing negative draft for your appliance that pull air from inside. You need someone to come out and inspect your dwelling and get to the bottom of what exactly is causing the issue. Right now you are just guessing and so are we. If you have a cold roof/vented attic, you need a contractor to correct the venting. Then go from there. You cannot just block the soffit vents!!!

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To start with, trying to fixing things like using the ERV does not fix the reason for your problem, whatever that is…

What is your actual issue? Your post appears to be moisture. But could (and is) back drafting appliances etc…

First of all, where are you?
Your environment is the source of the problem. Need to know this.
If you live on top of Mt. Washington, NH where the highest recorded wind and temperature differentials exist, things like stack effect and building openings are unlikely the problem.

Next, blocking soffit vents will not produce enough pressure reduction inside the building to backdraft appliances from “Stack Effect”. So this is not the problem. It may and likely exacerbate the problem that already was present before the install. There are a lot of fixes, but only one solution to your problem. You don’t need fixing.

As for your children’s health, making your house so tight could be how you caused this problem. I have had many clients who took it upon themselves to add “energy efficiency” procedures after their house was already weatherized, removing the required ventilation to the house. If a building science contractor so much as caulk one window, they must test a dozen things like the CAZ Zone (back drafting appliances). I have worked on houses that killed children’s pets because of carbon dioxide (not CO)! You’re not alone.

You need to quit doing what you have been doing.
I would be interested in the past history of this fiasco. Will tell exactly what the problem is NOT. Remove all potentials and you end up with the solution.

Hello,

Thank you all for your replies! I certainly appreciate it. To answer your questions, they did install baffles, although most of them are crushed. All of my ductwork is located in the basement ceiling area. There was a photo taken of the top plate in the attic, which is concerning. Photos attached.

I’m needing to find who CAN troubleshoot this issue as so far no one has been able to do this. I want nothing more than to move on with my life from this never-ending nightmare.

Yes, there certainly is a ridge vent and yes, the stack effect is very much a factor in this situation. The problem is finding who can do this in my state of Wisconsin where most are knowledgeable about their cheese, beer, and Green Bay Packers. Not building science issues.

I am located in central Wisconsin. None of these stranger occurrences began until after this insulation was added to my attic.
image8

Attaching several photos…carpeting

I will disagree with you on this opinion. An/the attic is not a habitable space. It is not or should not be connected to the habitable space. There maybe openings in the ceiling for systems such as electrical boxes for lighting, possibly bathroom ceiling fan, and HRV or ERV system registers. They should be sealed.
I would retain a home energy consultant. A diagnostic tool will be used to determine how much air is entering or escaping from your home.
Just my 2 cents.

Questions. 1: How do you know your home is air tight? 2: Heating/Furnace energy? 3: Solid fuel or LP/NG fireplace?

Agreed. So particulates are being sucked into the home. Would you consider HVAC (air return, perforated return duct, undersized or missing filter)?

Lower baffles are for air flow from lower to upper to protect the roof from heat. The upper vents discharge air. If the lower vents are blocked, it will increase pull from the basement, but not as much as you describe. In order to get a larger stack effect, you need a very large pressure differential. Did anyone measure that (pic of manometer)?

Supply and return?
Depressurization of the house happens from the duct when you have “supply air duct” leaking to the exterior of the building. When SA and RA are in the same zone, there is no pressure change. RA leaks pressurize the interior and nothing will come into the house when it is under pressure.

Yes, they leak there. Again, you need a huge pressure differential to get the leak you say you have.

So did anyone measure for this in your building science assessment? Did they test with/without the HVAC fan running?
How is it a very much a factor?
What about the blower door test report? It has more needed info than the pic shows.

Again, the problem is not the added insulation. It just contributes to the issue you’re looking for. If the real problem is addressed, other stuff you see will just go away.

The picture of your attic shows a small amount of what looks like cellulose insulation and something shiny.

Did they install a radiant barrier?

The only way you could get the kind of backflow through the house via the attic that you describe is if all you had was a power vent installed in the attic and the bathroom and or kitchen exhaust vents terminated in the attic.

You stated you have soffit vents and a ridge vent with most of the soffit baffles damaged, telling me that there is some soffit venting. But even if the soffits were completly blocked, the ridge would still allow enough air in at some point along the vent to prevent any excessive negative pressure from building in the attic space.

Another thought is you may want to have your ERV system double checked, it may be improperly installed or not working correctly.

If your house is sealed tight, and you have high CFM bathroom vents and or kitchen vents, terminated in the attic or to the exterior, these systems can create a negative pressure in the home as well, but the ERV system, if functioning properly, should prevent any negative pressures from building in the home.

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We use LP for heating with my forced air furnace. Woodstove also in the full finished basement, but goes unused. Blower door test came back at 400 at 50CFM. Although I’m not sure i believe that number.

Thank you,

Michelle Castile

We removed the electronic air cleaner as it did not catch anything. Installed a housing and merve 13 carbon filters instead. They come out white within 3 weeks and must be changed no less than every 4 weeks.

The problem began after the insulation was added, they also added a gas powered water heater when we had an electric water heater for 30 years. This was installed next to my furnace and clothes dryer without a worst case draft testing done.

Photos of how my ERV is set up. We do have a bathfan that leads to the attic as well as a kitchen exhaust that leads to the back of the house outside.

So you have a gas furnace and a gas water heater which you didn’t have before. Which appliance is backdrafting and who determined that it does? Do they backdraft while no other exhaust (bath, kitchen, etc…) are running? Did you have an HVAC tech look at your backdrafting appliance, what did they say? Something is missing from what you are telling us.

So, you are saying that your gas-fired water heater, (presumed) mid-efficiency furnace, and clothes dryer are all located in the same room? Add up the BTU input needs of each (on the manufacturer’s label for each). Also calculate the room volume in cubic feet. You need at least 50 cubic feet of room for every 1,000 BTU per hour of aggregate input or the room the appliances are located within will be considered to be “confined space,” creating negative pressure and potentially starving the appliances of combustion air. To alleviate a confined space, you need openings into the interior door to that room of about 1 square inch for every 1,000 BTU aggregate input OR an opening to outside the house of about 1 square inch for every 2,000 BTU of aggregate input.

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Thank you for the reply.
Now, calculate, combustion air for each appliance.
Try this link… CFM Airflow Calculator
I will continue reading the thread.