garage on the south to the two-story shed roof home to the north. This “
outdoor room” would connect the front yard, backyard, garage and main living
spaces. In short, it would be the central organizing spatial element uniting
the disparate places on the property — the departure point that gives clarity
to moving in and out of the building.
I know architects always blame zoning ordinances for screwing up their
design intentions, but this time it was true. Local zoning rules don’t allow
an open-air breezeway between a house and an attached garage, so the
breezeway became an entry vestibule but retained its initial intended role
as the lynchpin of the design. And the name stuck — “Foyer House” just
doesn’t have the same ring to it.
reduced demand, renewable Supply
The Passive House standard results in an extremely energy-efficient
building. This reduction in heating and cooling loads allows designers to
use innovative systems to meet the reduced demand.
The heart of the Breezeway House’s heating system is a 120-gallon TiSun
solar hot water tank that supplies the domestic hot water (DHW) system
and the hydronics. The tank has about 110 gallons of hydronic water storage,
with another 10 gallons of DH W storage in a stainless steel heat exchanger.
Most of the windows in the Breezeway House are on the south side to
take advantage of passive solar heating in the winter. Shading prevents
34 May 2012 SOLAR TODA Y solartoday.org
In addition to exemplary energy efficiency and comfort, the Breezeway
House owners wanted a generous open floor plan for entertaining large
groups of friends.
Copyright © 2012 by the American Solar Energy Society Inc. All rights reserved.
The hot water from the hydronic system runs through a heating coil in the
ventilation air stream to heat the house and through pipes embedded in
the floor of the foyer to provide backup heat to the entry vestibule during
extremely cold weather.
Very hot (160o F/71o C) hydronic fluid surrounds and continually heats
the 10 gallons of water stored in the heat exchanger, acting as an on-demand
heater for domestic hot water. A second heat exchanger at the bottom of the
tank connects to two TiSun solar thermal collectors on the roof.
A Passive House is airtight, so an energy recovery ventilator (ERV) is
mandatory to ensure that pollutants and moisture do not build up in the
home. The overall efficiency and energy consumption of the ERV is critical
to meeting the stringent requirements of the Passive House standard. We
chose an ERV with an efficiency of 93 percent at 200 cubic feet per minute
(cfm), which means that only 7 percent of the heat in the home’s air is lost
in the exhaust.
In addition, we installed a simple geothermal heat exchanger in the
incoming ventilation airstream, which is connected to 800 feet of HDPE
“slinky” tube buried about five feet below the ground behind the home. A
glycol solution flows through the buried tubing and through a copper heat