Page 41 - The Homeowner's Handbook 2017

Exteriors / Roofing / Structure / Insulation / IAQ / Windows & Doors / Heating & Cooling / Lighting / Appliances / Plumbing / Finishes / Cabinets & Tops / Alternative Energy

GEOTHERMAL
Earth Energy GE Aros Smart Window
A geothermal heat pump (GHP) uses refrigerant-filled underground Air Conditioner Could
piping loops, installed horizontally or vertically, to exchange heat with
the earth. These systems work well in both warm and cold climates. Be a Game Changer
A good GHP is able to move three to five times more energy than it
consumes. Models are available for use with forced-air or hydronic
distribution systems. While the hydronic models don’t get water as hot Typical window air conditioners, the kind you pick up at
as a conventional boiler (122 °F, compared to 150 °F or more) their low Walmart for $150, are about as “smart” as a toaster and far more
temperature output is a perfect match for radiant floor heat. polluting. They’re noisy, inefficient, include minimal controls
and, if you’re lucky, contain an on-board thermostat.
DOMESTIC WATER HEATING Over time, we need to phase out this technology completely,
Multiple Options in favor of more efficient ways of cooling, such as heat pumps,
Most homes have reservoir-type water heaters, which use gas, pro- mini-split systems, evaporative coolers and geothermal loops. In
pane or electricity to heat water that is stored in a 50- or 80-gallon the meantime, GE came up with a solution.
tank until the water is needed. Other homes have tankless water The Aros, co-designed by Quirky and GE, is the first AC unit to
heaters, which heat water on demand. Another option, condensing include Wi-Fi compatibility. That means you can program and
heaters, capture the heat that would otherwise be lost in the exhaust control it from your smartphone or laptop. Just as importantly,
gases and use it to heat water via a heat exchanger. Recirculating the Wink app that controls it provides feedback on performance,
pumps move water from the source and back again, creating a con- telling you which settings will operate it most efficiently, based on
tinuous loop that results in no water wasted. GB the weather. Chances are, Aros can save you big on energy bills.
Just how much depends on your lifestyle. Simply setting the
Glossary of Terms temperature schedule for your work week and sleeping periods
Know the Lingo should save you 20 percent or more. If you’re a frequent traveler
or rent out your home on Airbnb, your savings could be much
■ ■ Annual Fuel Utilization Efficiency (AFUE): The percentage of a higher, as the wireless app allows you to minimize cooling when
fuel’s potential energy that a furnace or boiler converts to usable heat. the home isn’t in use.
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
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 CREDIT: GE
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. To figure out your “payback” on the unit, a simple formula is:
■ ■ Evaporator Coil: The part of an air conditioner or heat pump that 8,000 BTUs / SEER 10 = 800 W = .8 kWh
exchanges heat with the air in the home.
■ ■ Heat Exchanger: Located in the furnace or boiler, it transfers .8 kWh x $0.15 (average U.S. utility cost) = $0.12 per hour to
heat from the combustion chamber to the air or water in the heat run your window air conditioner.
distribution system. In a hot climate where the unit is run 24 hours a day for 125 days
■ ■ Heating Seasonal Performance Factor (HSPF): The heating efficiency
of a heat pump. It’s a ratio of the heat it generates over the heating of summer, your window air conditioner will have an annual
season, in BTUs, to the watt-hours of electricity it consumes. Heat running cost of $360 per year.
pumps manufactured after 2006 have to have an HSPF of at least 7.7, Let’s say you now have a programmable AC and can save even
but the best units have ratings as high as 10.
■ ■ Seasonal Energy Efficiency Ratio (SEER): The cooling efficiency a modest 20 percent over a comparable conventional unit. You
of an air conditioner or heat pump. It’s the ratio of cooling output will pay off the “extra” cost of the wireless unit in about three
to electricity used. The minimum SEER requirement for units years, because you’re saving $72 a year in energy costs. After
manufactured beginning in 2006 is 13. that, you’ll save a flat 20 percent on your energy bills every year
■ ■ Zoning: A method of partitioning a home’s hydronic or forced-air the unit remains in service. Not a bad deal.
distribution system into independently controlled comfort zones.

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