Page 27 - Green Builder Magazine Sept-Oct 2021

DOE Annual Building Science Roundup
SILVER LININGS

the drywall in the attic. upstairs bunk room and master bedroom.
The home achieved an air tightness of The windows are triple-paned, with
1.25 air changes per hour at 50 Pascals an insulation value of U-0.19 (R-5.26).
(ACH 50). To provide ventilation, a heat They have two low-emissivity coatings
recovery ventilator (HRV) was installed to help minimize radiative heat trans-
to bring in fresh air through a MERV 12 fer through the glass. The windows are
filter and to exhaust stale air. The HRV not gas filled due to the high altitude.
was separately ducted to provide fresh air All of them have aluminum-clad wood
to every room in the house and to exhaust frames. The windows have a high solar
air from several locations, including the heat gain coefficient (SHGC) of 0.50 to
kitchen and bathrooms, which have boost allow in beneficial solar heat gain in the
switches to remove steam more quickly. winter.
Motorized blinds were installed on the
HEAT REPELLENTS interior side of the windows and can be
The home meets all requirements of the set to operate automatically on a schedule
EPA Indoor airPLUS program, including to keep out unwanted summer solar heat
the use of low- and no-VOC and form- gain. Meanwhile, lighting controls are
aldehyde-free products. ENERGY STAR integrated with the home automation and
appliances, LED lighting and low-flow energy management system.
WaterSense-labeled fixtures add to energy Hunter Mantell-Hecathorn says proj-
and water savings. ects such as this one for his parents are
A 95 percent efficient boiler provides an example of the company’s motto, “per-
domestic and hot water for the hydronic sonal attention to detail, one home at a
radiant floor heating for both floors, con- time.” Mantell-Hecathorn Builders limits
trolled by four smart thermostats. Cooling the number of projects it takes on to three
is provided by a SEER 16 wall-mounted to five per year so that Hunter or Greg can
mini-split heat pump installed in the liv- personally be on site daily to ensure that
ing room, and three ceiling cassette-style quality standards are being met by the
mini-splits installed in the upstairs hall, subcontractors and crews.

HIGH HOPES. A vented attic
includes 23 inches (R-60) of
blown fiberglass.

LOCKED IN. Triple-paned
windows with an insulation value
of U-0.19 (R-5.26).
COURTESY OF MANTELL-HECATHORN BUILDERS AND MARONA PHOTOGRAPHY

CENTER PIECE. Dual
2-by-4, 24-inch on-center
stud-framed walls.

www.greenbuildermedia.com September/October 2021 GREEN BUILDER 25