Literature Review on Building Envelope, Heating and ... - Beeshive.org

healthy, sustainable, durable, and affordable housings. The house is a 107 m 2 (1152 sq.
ft.) bungalow. The approaches for the design, materials, and construction method were
discussed and agreed to by the First Nations Tribal Council.
The building envelope: In the exterior walls, I-beam trusses were used to accommodate
additional fibreglass insulation to a total of R-50 (RSI-8.8). Fibre cement board siding, a
composite material of cement and wood fibres, finished the outside. The fire resistance
property of the fibre cement siding lowers the threat from forest fires that are common in
the region. Two layers of drywall were used in the interior face of the walls to act as a
heat sink for storing heat.
The triple-glazed, low-e casement windows can be opened to provide cross-ventilation in
summer. Fixed, sealed window units were also used.
The attic was insulated with R-60 (RSI-10.6) blown-in-place fibreglass. Metal roofing
was used for durability.
For the foundation, insulated concrete slab was used. Three layers of 600 mm (24 in.)
styrofoam insulation (a total of about R-30 (RSI-5.3)) were placed below and around the
concrete slab.
Power and utilities: An integrated combined heating and utilities module, EcoNomad®
was used to provide heat, power, drinkable water, and wastewater sufficient for a family
of five. EcoNomad is operated by a small 6 kW diesel generator, which co-generates
electricity, space heating, and domestic hot water. The system uses 20 to105 ampere-hour
sealed batteries configured in a 48-volt system. Photovoltaic panels and a wind generator
provide backup power to the batteries. Four photovoltaic panels, each provide 75 watts at
peak and produce up to 1/3 kWh of electricity. A wind generator, mounted on the roof,
produces 550 to 600 watts of electricity.
The concrete slab was heated by a hot-water radiant floor heating system, which allows
for a low temperature setting indoors. The concrete slab and the double layer of gypsum
walls provide thermal storage for the house.
Ventilation was provided by a balanced HRV system.
Healthy features: Low VOC paint was used on the walls. Cabinets were made of boards
that combine straw fibres and non-toxic resins. The radiant floor heating does not stir up
dust compared to forced air systems. A balanced HRV continually provides fresh air and
removes stale, moisture-laden air. Closets did not have conventional doors to allow for
air movement to help preventing condensation and mould growth.
Environmental efficiency features: The EcoNomad utility unit uses a small diesel
engine generator that achieves over 90% fuel efficiency by producing electricity as well
as reclaiming heat simultaneously. Wastewater is reclaimed and treated for use in toilets.
PERD-079: Task 2 - <strong>Literature</strong> <strong>Review</strong> 61