Merry Christmas!!! WE PASSED THE TEST!!!
There are many reasons to celebrate this day. For one: our son Joel was bornthis week 37 years ago in Nampa, Idaho! We carried him home from the hospital in the red Christmas stocking with white ruff he still wears as a Santa hat at Christmas time.
For another: We spent the most wonderful early Christmas with our 2 daughters Erin and Amy (we’re in NYC with Joel for the big day, so did our first celebration last week). We went to the Nutcracker, then to McMinnBill’s house and made a Net Zero gingerbread house, both Wood family traditions (Bill is Amy’s Dad).
Then, of course, there are the geese-a-laying, maids-a-milking and the International Climate Accord and the fact that we’re still in love after 41 Christmases, you know, stuff like that. But today we want also to celebrate another gift of Christmas 2015, symbolized by these three Lords-A-Leaping!!!! Here we have Scott Kosmeki (Passive House consultant Hinge-Build.com), Ryan Shanahan (Passive House certifying agent from Earth Advantage) and John Mead (our builder from Cellar Ridge Construction). They are leaping to high fives around the air blower because WE PASSED THE BLOWER DOOR TEST!!! THE METER HAS SPOKEN!!!!
I’m sure many of you understand the Blower Door Test from your experience of the same, run on your own homes to evaluate air-tightness. Our certifier, Ryan Shanahan, sealed the front door hole with an air-tight barrier surrounding the air blower. The blower facilitates two tests: 1) It will suck air from the space, creating a negative pressure, drawing outside air in through leaks and weaknesses in our envelope. Then, reversing the flow, it will blow air into the space, creating positive pressure which will force inside air to the outside through the same leaks.
We have spent 3 months creating the most leak free envelope possible. The black plastic under the cement floor is sealed to the Blueskin barrier that seals the walls and ceiling. Windows and doors are sealed in place with sticky-backed butterflies, caulked flashings and coiled worms of expandable insulation foam.
Penetrations for electrical wires and ducting have been mindfully plugged. The Blueskin itself is engineered so penetrations by nails and screws are self-sealing as long as the carpenters are trained to never pull out a nail or unscrew a screw, even if they miss a stud. Signs on windows and doors remind everyone that air-tightness is our vocation in this brave new world of construction. And the eyes of the Gestapo of All Things Leaky are WATCHING YOUR EVERY MOVE!
Mind you now, we must meet the Passive House standard of leakage before we can move on with construction. Failing the test is not an option! We keep plugging holes until we pass!!! So you’ll understand what I mean when I tell you the pressure in the room was substantial and it wasn’t from the blower alone.
The German Passive House standard is .6 Air Exchanges per Hour at 50 pascals of air pressure (.6 ACH50). In the U.S. it’s Cubic Feet Per Minute divided by total area of floors, walls and ceiling or CFM/ft2. Confused yet? Just keep in mind that the our digital meter must read 183 or lower, ok? Well, when Ryan cranked up the negative (sucking) pressure for the first time, this is what we got: 340 I have to say a little panic ensued.
We all scurried around to find the leaks, holding our hands by window frames, corners and crannies and recalling and taping the best we could. Ryan doubled the suction so tiny streams of air coming in from the outside would be easier to feel. It’s amazing how much leakage can come through a tiny hole where the silicon bubbled on a minuscule seam.
After several minutes of that, a shout came from the back, “The bedroom door was open!” Seriously? Anyway, after that small trauma we tried again and you see why our Lords were leaping!!!! Our goal was 183 and we tested below 100 on negative pressure and below 90 with positive pressure. We extrapolated the numbers to find we also surpassed the German standard of .6 air exchanges per hour, coming in at .51 ACH!!!!!
Since passing our test, 3 inches of Roxul (spun volcanic rock) Insulation have been secured all around the outside of the Blueskin. 10 inches of dense packed fiberglass will be blow in to the inside walls tomorrow morning. Sheet rocking will begin on the inside while corrugated metal is added to the outside before the old bearded one attempts his ascent down our non-existent Net Zero chimney. And oh…remember to close the door. I mean, were you born in a barn? Wow! Just wow!!!
Anyway, to all of you out there, we hope your Christmases, Hanukas, Kwanzas, Solstice Celebrations and figgy puddings remind you of what and who matter most. We look forward to a New Year with you, as we continue to share our communal quest of the Net Zero life. Wait for it. Wait for it. Wait for it. If we keep trying, sooner or later we’ll get it right! Happy Birthday Joel. We love you.
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