Two flat-plate solar panels will produce 70% to 75%
of the energy required for domestic hot water.
is hardly any heat loss. If this were a
traditional stick-built house, it would
have required 10 to 12 tons of cooling.
Because of the insulation, we were able
to specify a 5-ton Altherma.”
The unit is tied into an 80-gallon,
stainless steel Altherma water tank.
Foley could have specified another
brand, but says the tank is of high
quality. Although the heat pump could
supply much of the energy required
to heat the water, Foley suggested two
Viessmann flat-plate solar panels for
the job as well.
“We hesitated to install a solar
thermal system for heating hot water
because the Altherma does a pretty
good job of producing domestic hot
water,” Lorraine says. “However, our
goal is to reduce fossil fuel energy con-
sumption as much as we can, so we
agreed. We have good southern expo-
sure on our roof where Dan installed
the panels and, with the 30% tax credit,
it was affordable.”
The solar panels should produce
70% to 75% of the energy required
for domestic hot water, with the heat
pump providing the remaining energy.
There are three zones of radiant floor
heating in the full finished basement
(which has an office, media room, full
bath and in-law suite), with a fourth in
the garage; the garage zone is isolated
with a heat exchanger and propylene
glycol to eliminate the risk of freezing.
The tubing is 1/2-in. Uponor HePEX.
The first floor is one zone split into
three areas using EWC dampers. The
first of two First Co. fan coils feeds
the heating and cooling to those
three areas. The second fan coil, in
the attic, heats and cools the second
floor, which is split into two zones.
The fan coils include 5-in. Honeywell
media filters. Foley also installed a
200-cfm RenewAire Energy Recovery Ventilator.
budget and will meet her energy-effi-
At the time of this writing, Foley was
planning his second Altherma project
for the personal residence of David
Peabody, AIA, LEED, a Passive House
Certified Consultant and principal of
Peabody Architects, a residential green
In addition to the innovative
mechanical system, the Horbaly house
features many other energy- saving
technologies, such as:
for the foundation and lower level
for the upper walls and roofs
They also hope to install a wind tur-
bine in the future.
“We’ve estimated that our cost to
heat and cool the house will be approx-
imately $700 per year,” says Lorraine,
who was hoping that she and Judd
would be able to move into the house
within about six weeks from the time
of this writing.
THE RIGHT FIT
What made the Altherma a good
fit for this job? “It met the needs of
the client,” Foley says. “It fit with her
Lisa Murton Beets is a Cleveland-based
freelance writer and frequent contributor to Green Mechanical Contractor
and Radiant Living magazines.