Page 37 - Green Builder Sept-Oct 2019 Issue

Annual Building Science Roundup 2020 A GRAND SYNERGY

inexpensive to live in for years to come.”
Habitat for Humanity, Grand Traverse Region engages in a vari-
ety of events designed to educate the community about the need
for affordable housing, and the benefits of net-zero energy homes.
Habitat home owners also learn about energy-efficient construction
through the sweat equity hours they put into building their homes.
The Habitat affiliate also teaches homeowners how to keep the
house running efficiently. They are shown how to change the filters in
the mini-split air handlers and the energy recovery ventilation (ERV)
system. They learn about habits that can increase or decrease their
Airtight utility bills. Homeowners are given a comprehensive home opera-
planning. tion binder that includes a sustainable energy manual, schedules
for regular maintenance activities, and information on how to do a
Fiberglass
COURTESY OF HABITAT FOR HUMANITY, GRAND TRAVERSE REGION and cement warranty information.
self-guided home inspection. The binder also contains manuals for
and foam
insulation,
all of the home’s appliances and mechanical equipment as well as
lap siding
For Habitat homeowners, the economic impacts of energy-efficient
give the
housing have been life changing. “Previously if you took our gas
home an
bill and electric bill, it was over $300 a month,” says one Depot
R-value that
Neighborhood homeowner. “Now, our electric bill is under $10 a
is twice
month. I can actually afford to not only save for repairs and upkeep
Michigan’s
required total
save for our kids’ future.” GB
(per code).
unit to vary its speed and output to match the comfort needs of the on the house, and make the payments on the house, but I can also
home’s occupants. KEY FEATURES
The heat pump has a cooling efficiency or Seasonal Energy
Efficiency Ratio (SEER) of 18, a heating efficiency or Heating Season DOE ZERO ENERGY READY HOME PATH: Performance.
Performance Factor (HSPF) of 9.3, and a Coefficient of Performance WALLS: R-43: 2-by-6, 24-inch o.c. with 5.5-inch R-23 blown fiberglass
(COP) of 3.44 (which exceeds the current Federal minimum efficien- in cavity, 0.5-inch OSB, two 2-inch layers XPS R-20 rigid foam on
cies). A heat pump water heater with an energy factor (EF) of 2.75 exterior, fiber cement lap siding over 1-by-4 battens.
provides domestic hot water to the home. An energy recovery ven- ROOF: Raised heel trusses, 2-foot overhangs at eaves and gables,
tilator (ERV) provides ventilation for the air-tight home. asphalt shingles.
ATTIC: Vented attic with 20-inch (R-80) blown cellulose insulation,
OTHER COST CUTTERS plus closed-cell spray foam at eaves and penetrations.
All lighting is provided by LED based and all appliances are Energy FOUNDATION: R-22.5 ICF foundation walls, three 2-inch layers EPS
Star rated. The home’s design optimizes natural daylight to elimi- under slab for R-30.
®
nate the need to use electric lights during the day. WINDOWS: Triple-pane low-e, argon-fill, U=0.19.
The home is expected to cost its owners about $106 per year, or AIR SEALING: 0.88 ACH 50.
roughly $9 per month, in energy bills. The home achieved a Home VENTILATION: ERV.
Energy Rating System (HERS) score of 36 without factoring in the HVAC: Ductless mini-split heat pump, two indoor wall units, 18 SEER,
roof-mounted solar panels. With the panels, the home achieved a 9.3 HSPF.
HERS score of -1. Over the course of a year, this net zero home can
produce as much energy as it uses. For this home, this equates to HOT WATER: Heat pump water heater, 2.75 EF.
about $900 in annual energy bill savings for the homeowners. LIGHTING: 100 percent LED.
®
The home also includes water-saving features such as low-flow APPLIANCES: All Energy Star .
shower heads, toilets and plumbing fixtures, and an irrigation system SOLAR: 7.43-kW PV.
that is LEED certified for maximum water efficiency. WATER CONSERVATION: All fixtures low flow.
“Net zero is where it’s at,” says Habitat board member Ryan
McCoon, who served as project manager during the planning stages ENERGY MANAGEMENT SYSTEM: Energy monitoring of PV HVAC,
appliances and plug load.
of the Depot Neighborhood project. “This is the direction everyone
should be going. Low energy and water use mean this home will be OTHER: No-/low-VOC paints.

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