- advanced air sealing -

what's under the skin at 340 fairfax?  

you won't see it, but at 340 Fairfax, we used cases of caulk, cans of foam and ½ mile of building gaskets to eliminate air leaks.

our aim was to stop uncomfortable drafts, unhealthy summer heat and humidity and cold winter dryness.


we knew these were the elements that could compromise our health, wellness and comfort. Plus, air leaks increase dust, introduce harmful pollutants and run up our energy bills.

So we wanted the house as airtight as possible.


but when we were done, we really didn’t know how good of a job we had done.

did our air sealing efforts earn an A+, C-, D or even an F?


 -- we HAD to find out -- 

we scheduled a test to measure the airtightness using a device called a blower door. the blower door was installed in an outside door. the frame fits tightly, leaving little to no leakage around the enclosure. then the blower pulls air out of the house.




when the pressure inside the house reaches an industry standard of -50 Pascal, the airflow is measured through the fan. then all the information is received by a complex software, which tells us how we did on air sealing the house.

the good news is we passed.


with flying colors.


here’s how we know:

a popular method to evaluate house air leakage is to calculate the Air Changes Per Hour with the blower door running. scientifically, it is written as ACH(50)

in simple terms, ACH(50) tells how many “house-fulls” of air will go through the fan in one hour to maintain the -50 Pascal pressure. in other words, how many times will the blower door turn over the air in the house in an hour? of course, the lower the ACH(50) the more airtight the house.

meeting the minimum allowed by the building code would earn us a D-. if our house tested at the code maximum, we did the worst possible job we could legally get away with. we kept our fingers crossed for a better grade, confident all that effort had paid off.


NC code doesn’t allow more than 5.0 ACH(50).


our house leakage was tested at .85 ACH(50)

a second method might be easier to understand, called the equivalent leakage area.


if you waved a magic wand and brought all the holes and cracks into one big hole the equivalent leakage area represents the size of that hole.

at 340 Fairfax, our equivalent leakage area was measured at 60.4 square inches.


that size hole is a wee bit smaller than an iPad.

step into 340 fairfax and you'll feel the difference that size of a hole makes in the overall comfort of our home.  it's never drafty, dusty or humid.  we won't suffer the horrible effects of winter's dry air.  our power bills will be cheaper.  and, because we're using resources wisely to protect our home from the pollutants outside, we're helping the environment by easing the carbon burden our home emits into the air around us.  

that's a home like you've never seen.  it's an experience you can only imagine.