Indoor Air Quality of Texas

12/16/2019

We sealed the ductwork in this 5 system home over the past few days. This beautiful Kentucky estate is almost 200 years old! They had humidity issues as well as other comfort problems. So interesting to go to other parts of the country and see how differently things are done. Metal ductwork is everywhere, but no one uses mastic to seal the ducts. Occasionally tape will be used. Consequently, there was a lot of leakage for us to seal. We sealed a total of 1224 CFM of leakage over the 5 systems. Not including the huge gaps we hand sealed.

09/19/2019

Aerosealing the ductwork in this 120 yr old historic home in San Antonio today. Helping to get their humidity under control. Started at 225 CFM of leakage. By the end we will be close to 20 CFM remaining. 225 CFM is like a 6x8 inch hole in the ducts that’s letting in all the heat and humidity from the attic. The second two pics are the consequences of duct leakage: air sucked through the insulation which is acting as a filter, creating discoloration and growth and insulation on the back of the supply registers.

@ San Antonio, Texas

05/10/2019

Ductwork is an important part of the building envelope and the quality of the install is often hidden from view. Here is a 1980’s metal supply plenum with grey Mylar flex. Someone took the time to seal the insulation liner to the plenum, so you’d think that the ductwork is sealed.....wrong! Swiping right to the 2nd picture, removing the outer layer, you see gaps in an unsealed metal start collar. This leakage has been here for some time as the insulation is discolored. This ‘staining’ is due to the cold air from the duct leakage making the insulation cold, which caused condensation in the attic. When the unit isn’t running and you aren’t actively pushing air into this attic, this is a building envelope leak causing: dust, bugs, humidity to get into the house and into the air stream.

@ Travis County, Texas

05/02/2019

We are sealing up some 🐀 holes today. If you see insulation start to appear behind your registers, you probably have duct leakage. Not only can duct leakage impact your indoor air quality but mice droppings and fluids can be toxic and even deadly to humans. Not something you want in your air stream.

04/11/2019

There is 55 cfm of leakage between these two leaks in the supply ductwork of this system. Imagine 55 basketballs of cold air going into the attic every minute the unit is running. The white streak in the first pic is Aeroseal starting to seal the gap. This will be hand sealed with tape and mastic as well. Part of this truss actually runs through the duct! It’s a bad idea to have organic materials (like wood) inside ductwork, especially the supply side. After we seal, we will encapsulate the wood in mastic, so that it’s technically out of the duct. Not the best solution, but there doesn’t seem to be many other options. Aeroseal will seal these ducts from 150 cfm down to 15-20 cfm.

03/10/2019

Here is an example of Aeroseal sealing a leak in a ductboard trunkline. Aeroseal works on all types of ductwork and building materials, sealing holes up to 5/8”. You can see the grey discoloration of the ductboard that is actually supposed to be yellow. That is from years of puling attic air and moisture into the duct system. Older homes, like this one, look nice and well maintained, but are more connected to their attics and crawlspaces than you think.

02/27/2019

We sealed the ductwork in this 80 year old home. After finding two disconnected ducts and partially sealing the return, we started Aerosealing with 200+ cfm of leakage. We reduced that to just 24 cfm. The first picture is inside the return cavity. You can see where I stoped hand sealing and the blue circle is pointing out where continued sealing. The next picture is our sealing profile showing an estimated 15% on the heating & cooling portion of their utility bill. The last two pictures are the discounted ducts we found: one didn’t have a panduate strap or any fluid applied sealant and the other one wasn’t attached to the sheetrock.












@ San Antonio, Texas

12/18/2018

Anyone else glue a magnet to the back of their drill to hold screws?

12/06/2018

Here is a picture of a standard, internally insulated, supply bucket. All of the seems are notoriously leaky. Just looking at the first picture you may not think so but swiping to the second picture you can see where the cold air has blown onto the insulation, creating a cold surface that can then condense the humidity from the attic. This is just one of the 20+ supply buckets in this home, all of that small leakage adds up! - death by a thousand cuts.

10/22/2018

Here is a great article about indoor air quality.

That face above is of a physician, alchemist, and astrologer named Philippus Aureolus Theophrastus Bombastus von Hohenheim. He is deemed the father of toxicology and is better known by the name Paracelsus. I begin this article with him because Dr. Brett Singer, at Building Science Summer Camp this y...