A quite week. The insulators had other work scheduled but got in a couple hours to clean up Monday, they are coming back Friday to finish the insulation installing. And do a prelim blower door test
Got through the Framing Township inspection. Had a major error, a beam was 3′ out of place. That’s all fixed and when the insulation inspection is complete it’s drywall time.
I’ve been cleaning window seals in prep for the NJ Zero Energy Ready Homes program official blower door test. We noticed a number of the exterior window seals were knocked out of their track. And I noticed there was lots of building debris on the seals.
Last week the roofers did the cooper roof. See photos below:
Build Tight – Ventilate Right
One of the most important thing in building a Energy Efficient house is building it Tight”. The tightness of a house in measured in Air Changes Per Hour. This measurement is done by depressurizing house to 50 Pascal’s. A Pascal is a measurement of vacuum, it used to me measured in inches of water in a column. It is accomplished by putting a big fan in the doorway and sucking the air out of the house until you get to 50 Pascal’s then measuring the CFM of the air leaving the house..
The 2015 building code calls for 3.0 ACH50 to give you a reference point. We test our house at 1.0 ACH50 last week after the closed cell foam was sprayed. I was hopping for less, maybe a 0.5 ACH50 or lower, but as I said in another posting my design with the roof angles and changes didn’t help.
I think we are at 99% sealed at 1.0 AC50, but I’d like to get to 100% I asked a few people for tips on finding the leaks. The best suggestion was to warm the house to apx. 20 degrees above the outside temp. displeasure the house to 5 Pascal’s and using a thermal imaging camera to see the cold air leaking in. Using the torpedo heater I was running up the temp waiting for Ken to come. I got the idea to use my laser thermometer see if I could see a temp different any where that may show up where the leak was. It worked. Where we suspected the leaks were I saw a 3 to 5 degree difference is wall temps with in a foot circle. In other words, the wall temp was 65 and moving just 6 to 12 inches it would drop to 60 to 62. The only place this happened is where we suspected a leak was, no where else. Ken had a plan to fix the leaks so I just told him to proceed.
We will do another blower door test when Ken completes the cellulous installation.
On Wednesday Ken Fields of FSI started the cellulous installation by first instating a Poly bagging material that holes the cellulous in tight. The poly is stapled drum tight.
Then the cellulous is blown in.
Most people have never seen windows like these. European style, tipple pain, argon gas filled, no thermal bridging, R-8 for the opening windows. German Passive House certified. KlearWall windows, the North American branch of Munster Joinery and are made in Ireland. Here is a thermal image of the windows performance. Out side air temp 15 and inside temp 65.
How they work: First the handle, when down the window is locked. Then, when at 90 degrees the top tilts in for ventilation. Lets air in but keeps the rain out. Also secure enough to leave open while your gone.
In the up position the window swings in. Wide open. The Europeans say they only do this for cleaning. A friend in a passive house says the same thing. He says the tilt opening is more than enough ventilation.
Note the latching mechanism. The windows latch in 4 different location to ensure an air tight seal.
Once the closed cell foam was applied the house should be tight, so we could do a blower door test.
The front door is blocked and a fan in installed. The fan sucks the air out of the house to a difference the house pressure at negative 50 Pascal. Pascal is a measure of pressure. A typical existing home might leak at the rate of 15 air changes per hour at 50 pascal. Our test It came out 780 CFM at 50 Pascal or 1.0 ACH50. That’s 1 air change an hour at a negative 50 Pascal. That’s tight, but……I was hopping to get it lower, a 0.5.
To achieve a Passive House rating 0.7 ACH50 is the target. I’m not shooting for a Passive House certificate but I’d like to get to a 0.5 ACH50. But most Passive Houses are box on box construction. My house is far from a box on box. In going over the house it was easy to see how all the roof lines make it extra hard to seal the house as if it were a box on box.
Finding leaks is more art than science. The fan is reversed, pressuring the house. We then look at likely places for leaks hold a smoke wand in the area looking at how the smoke behaves. We found some small ones but no big holes. We are going to do some research and give it another try before the cellulous is installed.
Once it warmed some more and the siding installation was underway the mason could start work on the masonry pillars. First chimney blocks were mounted on the porch deck, filled with concrete, and caped. The columns are put in place and the roof is strapped to a rod imbedded into the pillar.
Again, not every thing lines up like the drawings. The beam on the porch roof wasn’t center on the columns and need building up. See photos.
And almost done.