Here’s a list of great reference sites for those of you looking for looking for the nuts-and-bolts science that underlies the hands-on information I’m blogging about.
Building Science corp. has devoted itself to teaching about the science of building. If you’re looking for hard-core, well researched information, start here. This should be on every builder’s “must-read” list. I cannot recommend it highly enough.
Building Science Guides and Manuals
Start here if you want to go right to the reference documents for the most important building science issues.
Building Science Information Sheets
Read these if you want a short overview of the most important building science issues. This is a great place to start if you’re new to the field.
Ted's Energy Tips 
What would you advise me to do? I live in Houston, Tx., and I have Central Heat and Air. It is a one story house with the air conditioning system being above my master bath on one end of the house. That side gets much more dust than the other side. We replaced our air conditioning unit about two years ago. But the dust has been a problem since we moved into house 13 yrs ago. The house was built about 19 years ago. In my mind I am trying to connect a persistent, threatening cough that has gone on for years to this dust problem. It is severe. What would you suspect in the attic? And who do I call that I can trust to help me? Any suggestions at all would greatly be appreciated.
I would definitely recommend having the ducts evaluated/tested. There’s a couple steps to this:
1 – the ducts are pressure tested to determine if there are any substantial leaks. This is done using a device called a “duct blaster” and that is really the only valid way to test the ducts for leakage. People may try to convince you otherwise. If they do, that typically means that they don’t have the equipment and will try to do a visual inspection only, which can miss a lot of huge leaks.
2 – if the leakage test shows significant leakage, then the ducts have to be carefully visually inspected. Sometimes, they can locate the duct leaks using a thermal imaging camera to look around the house for telltale signs of problems while the duct blast test is going on. Otherwise, it’s a process of elimination.
The best qualified company to do this would be an independent energy auditor who specializes and is trained in these types of tests. There should be a number in your area.
p.s. I hope you survived the hurricane without too many ill effects. From the news, your area was hit very badly!
Would like to talk to you about an attic insulation mold issue.
I’m happy to answer questions on TedsEnergyTips so others can learn from the discussion. However I no longer take on private clients.