Page 47 - Green Builder Homeowner's Handbook 2016

Exteriors / Roofing / Structure / Insulation / IAQ / Windows / Heating / Lighting / Appliances / Faucets & Fixtures / Finishes / Cabinets & Tops / Alternative Energy

GEOTHERMAL IMAGE: UPONOR (WWW.UPONOR-USA.COM) GE Aros Smart Window
PHOTO BY JOEL SILVERMAN Air Conditioner Could

Earth Energy Be a Game Changer

A geothermal heat pump (GHP) uses refrigerant-filled underground Typical window air conditioners, the kind you pick up at Wal-
Mart for $150, are about as “smart” as a toaster and far more
piping loops, installed horizontally or vertically, to exchange heat with polluting. They’re noisy, inefficient, include minimal controls
and, if you’re lucky, contain an on-board thermostat.
the earth. These systems work well in both warm and cold climates. Over time, we need to phase out this technology completely,
in favor of more efficient ways of cooling, such as heat pumps,
A good GHP is able to move three to five times more energy than it mini-split systems, evaporative coolers and geothermal loops. In
the meantime, GE came up with a solution.
consumes. Models are available for use with forced-air or hydronic The Aros, co-designed by Quirky and GE, is the first AC unit to
include Wi-Fi compatibility. That means you can program and
distribution systems. While the hydronic models don’t get water as hot control it from your smartphone or laptop. Just as importantly,
the Wink app that controls it provides feedback on performance,
as a conventional boiler (122 °F, compared to 150 °F or more) their low telling you which settings will operate it most efficiently, based on
the weather. Chances are, Aros can save you big on energy bills.
temperature output is a perfect match for radiant floor heat. Just how much depends on your lifestyle. Simply setting the
temperature schedule for your work week and sleeping periods
DOMESTIC WATER HEATING should save you 20 percent or more. If you’re a frequent traveler
Multiple Options or rent out your home on Airbnb, your savings could be much
higher, as the wireless app allows you to minimize cooling when
Most homes have reservoir-type water heaters, which use gas, propane the home isn’t in use.
or electricity to heat water that is stored in a 50- or 80-gallon tank until
the water is needed. Other homes have tankless water heaters, which To figure out your “payback” on the unit, a simple formula is:
heat water on demand. Another option, condensing heaters, capture 8,000 BTUs / SEER 10 = 800 W = .8 kWh
the heat that would otherwise be lost in the exhaust gases and use it to .8 kWh x $0.15 (average U.S. utility cost) = $0.12 per hour to
heat water via a heat exchanger. Recirculating pumps move water from run your window air conditioner.
the source and back again, creating a continuous loop that results in no In a hot climate where the unit is run 24 hours a day for 125 days
water wasted. GB of summer, your window air conditioner will have an annual
running cost of $360 per year.
Glossary of Terms Let’s say you now have a programmable AC and can save even
a modest 20 percent over a comparable conventional unit. You
Know the Lingo will pay off the “extra” cost of the wireless unit in about three
years, because you’re saving $72 a year in energy costs. After
¦¦ Annual Fuel Utilization Efficiency (AFUE): The percentage of a that, you’ll save a flat 20 percent on your energy bills every year CREDIT: GE
fuel’s potential energy that a furnace or boiler converts to usable heat. the unit remains in service. Not a bad deal.
Government standards that take effect in 2015 require AFUE levels of
82 percent for gas boilers, 83 percent for oil boilers, 80 percent for gas The Homeowner’s Handbook 2016 GREEN BUILDER 45
furnaces and 82 percent for oil furnaces.

¦¦ Air Handler: In a forced-air heating or cooling system, the air handler
unit moves heated or cooled air through the home’s ductwork.

¦¦ British Thermal Unit (BTU): The unit of measurement for heat,
whether it’s the heat given off by burning fuel or extracted from a
home for cooling. Technically, one BTU is the energy required to raise
one pound of water one degree Fahrenheit.

¦¦ Combustion Chamber: The part of a furnace or boiler where the fuel
is burned.

¦¦ Compressor: The part of the air conditioner or heat pump that
compresses and pumps refrigerant.

¦¦ Condenser Coil: The part of an air conditioner or heat pump that
releases heat from the surrounding air in cooling mode and collects it
in heating mode.

¦¦ Distribution System: The network of air ducts or hot water pipes that
delivers heat from a furnace, boiler or heat pump to the home’s rooms.

¦¦ Evaporator Coil: The part of an air conditioner or heat pump that
exchanges heat with the air in the home.

¦¦ Heat Exchanger: Located in the furnace or boiler, it transfers
heat from the combustion chamber to the air or water in the heat
distribution system.

¦¦ Heating Seasonal Performance Factor (HSPF): The heating efficiency
of a heat pump. It’s a ratio of the heat it generates over the heating
season, in BTUs, to the watt-hours of electricity it consumes. Heat
pumps manufactured after 2006 have to have an HSPF of at least 7.7,
but the best units have ratings as high as 10.

¦¦ Seasonal Energy Efficiency Ratio (SEER): The cooling efficiency
of an air conditioner or heat pump. It’s the ratio of cooling output
to electricity used. The minimum SEER requirement for units
manufactured beginning in 2006 is 13.

¦¦ Zoning: A method of partitioning a home’s hydronic or forced-air
distribution system into independently controlled comfort zones.

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