Page 45 - Green Builder Sept-Oct 2020 Issue
P. 45
DOE Annual Building Science Roundup A BETTER WAY
DINING
of classic wood windows. The engineered,
sloped sills form a negative pressure pocket
that keeps sashes securely in place and water
BEDROOM owing away from the home, even during KEY FEATURES
GREAT ROOM
MASTER the most adverse weather conditions. WALLS: ICF, 11-inch R-22 total: 2.5-inch EPS,
BEDROOM
In addition to the double-hung exterior 6 inch steel-reinforced concrete, 2.5-inch EPS,
KITCHEN 1/2-inch drywall.
windows, transom windows were installed
FOYER above interior doorways on the main oor ROOF: Hip roof; engineered 24-inch on-center,
and in the basement, to bring daylight into 7⁄16-inch OSB sheathing, synthetic felt rain-and-
BATH ice guard in valleys and eaves, 4-inch ridge vent,
the interior of the home, reducing the need 30-year shingles, 1.5-inch aluminum drip edge,
for articial lighting during the day. When
BEDROOM 1-foot overhangs.
lighting is needed, all of the xtures in the ATTIC: Vented attic; 16-inch R-50 blown cellulose,
home use LED light sources. 3-inch R-20 closed-cell spray foam on top plates;
GARAGE This home, with its standard features, R-20 blown cellulose in garage attic.
achieved a Home Energy Rating System FOUNDATION: Insulated basement, R-20 total: 11-
(HERS) index of , which is far better inch ICFs, waterproof membrane, concrete footers
than the typical HERS score of to for with integral interior and exterior drainage system.
new homes built to code across the country. WINDOWS: Triple-pane, argon-filled, vinyl double-
Calculated energy cost savings for this home hung frames, U=0.17, SHGC=0.21.
CHARIS HOMES are $ , a year. The homeowners report AIR SEALING: 1.41 ACH 50.
The Sanctuary, a low $ per month average electric bill, VENTILATION: ERV, MERV 11 filter.
and describe the home as “quiet, comfortable
HVAC: Combined heat and hot water with 0.95 EF
an outdoor condensing unit for a SEER
. and dust-free.” gas tankless boiler, hydrocoil and small-diameter
heat pump so the air handler can provide And, if homeowners wish to save more high-velocity ducts, and radiant floor heat in
heat from the boiler or cooling from the heat money, a smart thermostat includes mobile basement; 16.3 SEER heat pump AC.
pump. This conditioned air is distributed phone-accessed budget control features that HOT WATER: Combi boiler, 0.95 EF; central manifold
throughout the home via a system of small- maximize system eciency and real-time with PEX; smart recirculating pump.
diameter ducts. These ducts discharge higher energy tracking. Also, as a requirement for LIGHTING: 100 percent LED, motion sensors,
velocity jets of air into each room through the Department of Energy (DOE)’s Zero transom windows, daylighting.
multiple small, round supply vents. Energy Ready Home (ZERH) certication, APPLIANCES: ENERGY STAR refrigerator, dishwasher,
The main duct, or plenum, is one-fourth roof trusses were engineered to support microwave drawer.
the size of a conventional duct, and the future photovoltaic panels, and an electrical SOLAR: Solar ready.
branch ducts use exible ducting with an conduit for solar power was run from the
inside diameter of only or . inches, so attic to the electrical panel. WATER CONSERVATION: EPA WaterSense fixtures.
they easily fit within interior walls and Indoor air quality is a signature feature ENERGY MANAGEMENT SYSTEM: Wi-Fi enabled
oor joists. This allows more options for for Charis Homes. In , Charis earned smart thermostat.
keeping the ducts within the conditioned its second Leader Award from the U.S. OTHER: Electric vehicle charging; zero clearance
envelope of the home. The branch ducts Environmental Protection Agency shower and thresholds; no VOC paints, low-VOC
are factory-insulated and have gasket (EPA)’s Indoor airPLUS program (whose sealants and glues; formaldehyde-free hardwood,
plywood, adhesives.
connections to minimize air and thermal specifications are required to be met to
losses. The system provides quiet operation earn a DOE ZERH certication). The builder
and thorough mixing of air in the rooms for incorporates several features in the home
even temperatures. to support clean indoor air, including Meadows says the company uses DOE’s
installation of an energy recovery ventilator ZERH designation as a tool to educate
CLASSIC LOOK, (ERV) that brings ltered fresh air into the customers as to why building such a home is
CONTEMPORARY QUALITY home and exhausts stale air while, eciently worth the additional cost. “[In our education
The builder chose to install triple-pane recovering heating and cooling energy. center], we visually have a money display
windows that are argon filled and vinyl Other features include drywall that showing customers the amount of money
framed, with a U factor of . (R- .) and absorbs formaldehyde and volatile organic a ZERH home saves over the course of a
a solar heat gain coecient of . . These compounds (VOCs), ductwork that is self- -year mortgage,” Charis says. “Showing
windows are easy-to-operate double-hung cleaning and does not allow condensation to them the data helps to prove the investment
styles, where both sashes in the frame can build up within the tubing, zero-VOC paint, is worth it. But our biggest reward is
be moved up and down, helping to facilitate formaldehyde-free hardwood and plywood, comments from homeowners about how
cross ventilation of the home. and water-based wood nishes. comfortable their home, is and how low
A cove molded sash replicates the look Charis Homes’ Marketing Director Emily their utility bills are.” GB
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