thanks energy rater La...I will try to respond to all your questions. I appreciate your help.
We had the subfloor in our living room tested to rule out asbestos in it and it was safe, but was composed of a lot of cellulose. It is a type of particle board most often used to insulate walls I guess. I can see it is our walls as well. Our home was built in 1950 and has plaster walls and ceilings. Our ducts are in the walls that lead down to the basement where we have a forced air furnace. The go into the attic briefly for the two vents we have up there. Mostly hard ducts. One small line of flex duct that is newer and small area of insulated cardboard type product for cold air returns to two bedrooms which is also newer. We have return air ducts in both downstairs bedroom and in the living room which is the largest and most efficient one. No recessed lights or fireplace. The mold in the basement was from water intrusion. The basement was finished with drywall, carpet, ceiling and we had to rip it all out before we moved in. The home had set closed up for several months as well, which made the mold problem even worse. (at least we got a good deal on it, ha ha!) It was remediated for the 2nd time this past December 2012 by our air quality guy using a thyme based product to kill the mold and then with an application of a mold resistant sealant over every inch of the basement (mild safe antifungal but cannot recall the name of it.) Testing reveals no mold at all on first and second floors (which really did not have a huge mold issue to begin with per testing.) and basement current mold test reveals a very low amount of mold there. The basement is under the entire first floor, no crawlspace. I have noticed that when the furnace is on, I happened to be reaching up to check something and there are several areas along the basement ceiling where it meets the first floor subfloor and outside wall where I could feel cold air just streaming in from the outside. However, as I said, the basement does not have a high level of dust particulate at this time. Not sure if this outside entry of unfiltered fresh air would affect the overall dust problem though? The attic, which desperately needs a cleaning, may have had cellulose insulation blown in previously but the air quality guy said all he could see was some fiberglass insulation. I am seriously considering whether we need to get a water baseboard heating system as I have read that forced air heating systems are not recommended for those with allergies and asthma. Would like to take care of the dust regardless though. I think it accumulates whether the furnace/AC is on or not, but definitely worse with it on. It kicks on and I start to sneeze and nose starts running. But I can be out of my home for hours and be okay but when I step in, whether furnace is on or not, I start to itch my nose, feel irritated. Thanks for your help!
Oh, what is "mastic" by the way?
Reconsider the cause/effect of moisture in the floor and walls of your basement with your dehumidifiers.
Originally Posted by CarolinaDawn
<50%RH is critical in your basement and entire home. Saturated earth is under your concrete floor. A small amount of moisture moves through the concrete to the basement space. You must keep the space dry to avoid mold. When the outside air is +50^F dew point, infiltrating fresh air also carriers moisture into your home/basement. Not maintaining <50%RH because you feel less moisture gets to the drain is not acceptable. Not maintaining a fresh filtered air change and <50%RH are not acceptable for purging indoor pollutants and preventing growing biologicals. These are criiical issues. Get a new indoor air quality expert. ASHRAE and Americam Medical ASS suggest the fresh air change, merv 11 air filtering, and <50%RH.
Keep us posted.
Ok, met with air quality guy and he tested our RH..it is about 50-51% so he recommended turning only one dehumidifier on and setting it to 50% so that it kicks on occasionally when needed and doesnt run constantly. he suggested the musty smell might be from the fresh concrete used in the waterproofing that has not yet totally cured. It certainly was somewhat of a damp cellar clay type of smell. So hopefully this will dissipate with time. He is going to have a blower door test done and check for leaks and then possible install a Energy Recovery Ventilator (ERV) to help keep the pressure positive instead of negative therefore not pulling as much debris from the walls. Has anyone heard of this device and is it helpful for this type of thing in your experience? It will cost anywhere from $$$ to $$$ installed tho! We have already spent thousands upon thousands on this home's environmental issues!!! NEVER again will I get a bank owned home where they sell it "AS IS." At least I have some hope now though. Any other thoughts from anyone? thanks so much for your help!!!
ERV to keep a positive pressure in your home is not the best way. An ERV is a balance flow device that exhaust as much air as it brings in. They do conserve energy but that is not your real problem.
Originally Posted by CarolinaDawn
This is not about how air tight your home is. On windy days, most homes get enough fresh air. On calm days, your home gets much less fresh air. Because of all the problems you are having, just bring in the correct amount of fresh, filtered air that will pressurize the space. Forget the exhaust part, your clothes drier, bath fans, and kitchen exhaust hood need make-up air. 2,500 sqft. home needs about 70-80 cfm of fresh air when occupied.
I like the idea of having enough dehumidification to maintain <50%RH during all of the variable weather you experience in your area. Right now the outdoor dew point is low and dehumidification is minimal. When the outdoor dew points are high, you need about 70-80 pints of dehumidification to maintain <50%RH.
Filtered, fresh air ventilation and maintain <50%RH is the guts of indoor air quality. The operating cost to do this with well designed equipment is from upto a $1 per day during hot/cold weather and nothing during mild weather.
You can do this with residiental dehumidifiers and a make-up air inlet on a good air handler/merv 11 air filter.
I suggest long term, use a whole house ventilaitng dehumidifier. Units like the Ultra-Aire whole house ventilating dehumidifier are designed to ventilate, filter, blend, and maintain <50%RH throughout the home. With 80 cfm of filtered make-up air, a positive pressure will reduce infiltration of unfiltered fresh air.
Most of us have had to learn these lessons in good air quality the hard way.
Brands of equipment are not critical.
Your local a/c contractor can do these things for a modest investment.
Have your IAQ man contact me for help if he is interested. I have +15 years of experience with these kind of problems.
Thanks TB. I wanted to add that our outside air does not seem to be the problem. He has tested it against the inside air and the inside is where the problem is. Likely the broken down cellulose insulation inside the walls. The dust was tested and has a disproportionate amount of cellulose in it. Would the ERV not be able to create a more positive pressure system and let the dust stay in the walls? That seems to be the goal here. The amount of dust is our main problem right now since the dehumidification is going to be taken care of. We have at least a 13 MERV filter AprilAire expensive unit. We have also used room filters. This problem is much bigger than just getting a good furnace filter or even ensuring proper air exchange, etc. The dust is constant and very irritating to me, regardless of the weather outside. And even when there is no humidity. I am itching my face off so to speak and constantly blowing my nose. The "unfiltered fresh air" outside my home is WONDERFUL and I prefer it greatly to what I have to breath inside my house...
Using only makeup air without exhaust will produce much more positive pressure on your home. More positive pressure will slow infilteration through the walls. This is important. During strong winds, nothing will will stop infiltration.
Originally Posted by CarolinaDawn
Thank you TB. We live in a very low wind area...lots of trees to break the wind and sort of down in a protected valley type area. Do you think the ERV would be beneficial at least somewhat, for our problem? (provided the dust IS indeed coming from the insulation in the walls) We are also going to go ahead and replace the subfloor which is not a good material anyway, and we are getting rid of high pile carpet for a commercial type and getting rid of our stuffed furniture and using a leather couch we have instead. I am hoping these things will all help the problem. Any other ideas for dust control? Thanks so much for your help!
An erv will help somewhat, but not as much as a have a high quality filtered make-up air device to pressurize your home. Removing your carpet and subfloor will not help. Weekly vacuuming with a hepa filtered vacuum cleaner and wiping horizontal surfaces are the best ways of collecting settled duct from your home. Dust in itself is usually ot a problem if is dry. If damp is grows and is a health hazard to many.
Originally Posted by CarolinaDawn
A fresh air change in 4 hours, like 80-90 cfm of filtered make-up air and maintaining <50%RH through your through the all the damp seasons of the year are most important. I would suggest a whole house ventilating dehumidifier as a start to provide 80 cfm of filtered make-up air, blend the fresh air into the home while maintaining <50%RH during the wet times of the year. Units like the co-sponsoring Ultra-Aire are designed to introduce the correct amount of filtered fresh air into the home. The Ultra-Aire maintains <50%RH when the outdoor dew points are high and the a/c is running. Also the dehu will keep your a/c ducts dry when the a/c is not operating. After having fresh air and <50%RH, than tackle these less important issues if needed. Subfloors and well vaccumed carpets do not cause duct problems. There are studies that slow carper hold dust until you vaccum. Fresh filtered air, pressurize the home, and <50%RH!
You are ultimately responsible for your own health.
Keep us posted.
erv is an investment, a better investment is the whole house dehumidifier with fresh air intake.
still you need to seal the leakage sites. mine is the top of the line from teddy bear.
think of your house as inhaling..negative pressure, pulling voc's thru leaks into the house.
then exhaling pushing air out of leakage sites. you still have to seal the leak sites.
the blower door will show these sites, and you should mark the sites, take notes to
do the sealing down the road.
while it isn't humid now...it will be in a few months. as you have stand alone dehumidifiers, the
whole house systems do a much better job,
mastic is bucket of duct sealant, applied with a chip brush. here is a short video of how to
mastic seal ducts
here is a short video that shows how to apply mastic.
no foil tapes, no duct tapes. never ever.
there is also a excellet mastic tape, hardcast brand #1402 that seals well.
it seals metal to metal , metal to wood..as long as surfaces are clean & dry it works well.
if cellulose is in the walls then you seal the penetrations, caulk, & backer rods
for large openings.
here is a pic of the way I seal supply boxes from inside the house.
hope this helps, it has worked well for me for years.
if blower door is done, then testing ducts is a good option . keeping the air you pay to heat/cool is a cost saving idea
that is my advice, based on my years in the efficiency bizl
best of luck!
guess I need to attach the picturel!
and take the cover off the bath van & seal that oversized
Thanks both of you! Ok, our home is below 50% RH and the "dry" dust is still very irritating to me. I had to go outside to eat breakfast this morning due to the constant itching of my nose, face and blowing my nose! Could there be a VOC that is really the problem? Humidity is not an issue right now and I am still highly allergic to this house!