IAQ problems, mold in vents etc.
We live in a single story 2150 sqft home in The Woodlands, TX (just north of Houston). House was built in 2003. We bought it in 2007. Previous owner had a dog and even after steam cleaning the carpets we still encountered dog hair so we changed over to laminate floors and new carpet in the house in 2009.
We noticed a steady increase in blocked sinuses, sneezing, itchy eyes and allergies for the last couple of years. In Oct 2010, I had the ducts cleaned by a company and they found mold in the vents in the master bedroom and master bath closet. The company cleaned the ducts, used biocides (BBJ) and told us all would be good.
Our new laminate flooring seemed to have a problem settling down so we had to call out the installers atleast 3 times to adjust as it seems to be bowing and flexing.
I started looking into whether humidity was the culprit for all our woes. I checked a wall clock we own which has a hygrometer built in. To my horror, it was reading 80% humidity. So I called our regular a/c guys last month and they thoroughly checked our a/c and said everything was ok but that the vents still had mold in them. The duct cleaning company came out again and did additional cleaning and biocides under warranty.
Subsequently, I bought a portable dehumidifier from Lowes and am running it in the master bedroom and our allergy symptoms seem to be less (there is one return in the master bed). The dehumidifier reads around 70 ish when it has not run for along time (around 5 maybe 10% lower than the wall clock).
Points of note:
1. I have not checked my a/c size and will do that tomorrow and post here.
2. We keep the house at 75F all the time.
So after that long post my questions are;
1. Is putting in a whole house dehumidifier going to be a good solution to our problems? Is a whole house dehumidifier addressing the symptom and not the cause?
2. The a/c has no problems cooling but we constantly wake up at night with the air feeling stale and stuffy. Is there anything we need to consider changing in the a/c system?
3. What causes high humidity in the house? We do not have leaks and/or drips (I have checked the whole house).
4. I have checked a few whole house dehumidifiers and see that there is a fresh air option available. Is that a good idea for areas like Houston where the humidity is high? I am asking this from an IAQ point of view.
Instead of me going on and on, search my posts for most of your my suggestions to solve the problem.
1. Get your a/c removing as much moisture are possible. You ac coil temp should be 25-30^F colder than the return air temp.
2. Set the fan on the "auto" mode.
3. Check the amount of condensate that your a/c removes. Should remove 2-3 lbs. per hour per ton when operating. This assure the a/c doing its best.
With normal air infiltration, your home should be dry during peak cooling load. Hopefully, no supplemental dehumidification is needed during peak cooling loads. If the home is damp with the a/c removing proper water, look for excess fresh air infiltration/duct leakagein the attic.
Avoid watering the walls of your home with irrigation.
During evening hours and rainy days, supplemental dehumidification will be needed to maintain 50%RH when outdoor dew points are +60^F.
Check out the Ultra-Aire, a site sponsor, whole house dehumidifier. No fresh air until you can maintain <50%RH. Check my endless posts and Ultra-Aire.com. There will be other good suggestion, I am sure.
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"
Easy, but you need to get some info first! What is the RH% inside the home?
Originally Posted by tamudude
Whats in your air?If your humidity levels are low enough (55% or less) you shouldn't be having too much of a problem unless the enviroment you live in is condusive to mold. It happens. Easy way to get rid of it AND improve your breathing in the home is to get quality IAQ products. First: a UV lamp that has microwattage of over 80 mW at 1 meter. Be sure you know the distance they are measuring the output at. Any one can inflate a number by measuring closer to source. 2: get a quality filtration device. a better "filter" will catch the mold spores but even then your not going to remove many particles below 5 microns in size....thats important because almost 98% the particles in your air are between 1 and .3 microns in size (micron= 1/25,400 inches) Two steps to improving air quality are: kill it and capture it. Since you've already got a high output UVC producing lamp (and no, honeywell doesnt make good UV systems) you need to pick an electronic air cleaner. I recommend polarized media solely because of the ease of maintance. The 5" ones with big metal plates only have 48 sq ft of surface area and NEED (regardless of what people say) to be cleaned every 30 days. Cleaning them properly is a pain due to the electroplating process which makes them work. Look for a polarized media system with a merv 14 equiv or higher and a quality UVC lamp and your sniffles will vanish!