Energy Efficiency Project
In 1992-1993, I built a new home for our growing family and business. It
was designed to be very energy efficient:
- Double stud walls with 2" foam between
- "Perfect" Vapor Barrier
- Super thickly roof framing and insulation
- Air-to-Air Heat Exchanger
- Trane 94% efficient furnace
- No Windows on North side
- Buffered entries on back and front with some storm windows
- Low E double glazed windows with conservation panels
In 2008, I decided to have an energy audit done.
Focus on Energy
hooked me up
with Aaron Riendau, of St. Croix Energy Consultants.
He came and we pressurized the house with his blower door unit. He
tested our air exhaust appliances and the drafts on the furnace and
water heater. With all the doors closed, we looked all around the inside
of the house with his infrared camera.
When we put the house under pressure, we are able to induce drafts into
the house from the outside. When the outside air is either much cooler
or warmer than inside, we are able to see through where the outside air
is coming in.
I was shocked to see incredible leaks along the tops of my finished
walls, around window frames, even around electrical outlets on interior
I had thought that I had done a perfect job of sealing up the thermal
envelope. I would have been happy with a .5 ach but my home tested about
I knew from training that the leakier the home, the more expensive to
heat and to cool. On wind days, I was losing lots of energy due to
leaks. The air tests also revealed in part why my upper floor gets so
warm in the summer and stays so cool in the winter. The dormer lets
loads of air in and the backs of my finished walls are awash in flowing,
heat robbing air.
As my home needed repainting I decided to address as many of the known
air leaks as I could.
This section of my website is devoted to this project.
In pictures and words, I will be documenting the air sealing techniques
I am using to achieve a lower air exchange rate.
When I have all the work on the outside and in the attic completed, we
will retest to see how well my efforts worked.
Then, we will tackle the electrical penetrations and other mechanical
openings in the house, and all the weather strips on doors that are
And we will test again.
I will track my costs in time and material
And will post monthly changes in gas and electricity use over the next
several heating seasons.
We will assess the change in comfort throughout the our home too.
This is the
initial energy audit
on my home with project photos below.
The West Soffit of my home, before, and after actually. The
west side of my home is protected by a hill and trees. We get
more of our direct sun light in the east and west windows as
the sun is more direct when it is low. The tall poplars and
the hill and the trees beyond pretty well shade the west side
in the afternoon.
My "Insulation Dam". The once bright yellow insulation
is now a dull yellow gray/brown. It has been acting as
a 'furnace filter' for 15 years, catching the dusts
that have been blowing up through the soffits and into
my attic. When air blows through fiberglass, the
fiberglass loses its R-Value. Fiberglass has to be
contained on all sides to be effective insulation.
I had prided myself on the joy I get from insulating
and my ability. If you look at the left side of the
air chute, you see a gap in the insulation. This gap
is over the wall plate. Now, I have two wall plates,
so it is not as critical as if I had only one, but it
is still a reduction in insulation, left behind by the
Also, I suppose to save money, I cut the proper vents
in half. Proper vents are very cheap. I reduced the
air flow by half in each truss cavity. When I added
these in to the new garage, I used full width air
vents for maximum air flow above the insulation dam as
seen in photo 5.
My new insulation dam is also an air dam. I used left
over rigid insulation because it is easy to cut with
my Leatherman and it is easy to handle and shape. The
bottom edge is caulked to the osb wall sheathing. The
joints between the dam and the framing and roof deck
are sealed with low expanding foam.
My intent is to block all potential air flow from the
ceiling surface and to direct it up into the attic
itself, where it will be drawn out by the ridge vents.
Much later, when I am working on the inside of the
attic, I will seal any air leaks I can see as I seal
the nearby wall plates.
This portion of my garage had not been finished when I
built our home in 1993. In order to insulate the attic
over the garage, I had to install proper vents, or air
chutes, and insulation dams.
First, I removed the soffit panels from outside. Then
I stapled up air chutes, full with. Then I compass cut
short pieces of rigid foam to closely fit the contours
of the proper vents. I caulked these to the wall
sheathing and foam sealed the gaps.
Later, I will continue stapling up the air chutes from
inside the attic and will air seal the joint between
the wall and the ceiling rock.