9a. Home Heating Systems Heating Systems Heating System

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9a. Home Heating Systems
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Heating Systems

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Heating Systems

• Some hot water systems circulate water through
  plastic tubing in the floor, called radiant floor
  heating.

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Electric Heating Systems

• Resistance heating systems
• Converts electric current directly into heat
• usually the most expensive
• Inefficient way to heat a building
• Heat pumps
• Use electricity to move heat rather than to
  generate it, they can deliver more energy to a
  home than they consume
• Most heat pumps have a COP of 1.5 to 3.5.
• All air-source heat pumps (those that exchange
  heat with outdoor air, as opposed to bodies of
  water or the ground) are rated with a "heating
  season performance factor" (HSPF)

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Geothermal Heat Pumps

• They use the Earth as a heat sink in the summer
  and a heat source in the winter, and therefore
  rely on the relative warmth of the earth for
  their heating and cooling production.

Additional reading http//www.eren.doe.gov/erec/f
actsheets/geo_heatpumps.htmlsidebar
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• Geo Exchange Heat pump system Movie

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Worlds Largest Heat Pump

• The Galt House East Hotel and Waterfront Office
  Buildings in Louisville, Kentucky, use a 4,700
  ton GHP system to meet the heating and cooling
  needs of the complex.
• The 750,000-square-foot (70,000 square meter)
  Galt House East Hotel, completed in 1984, uses a
  1,700-ton GHP system, which cost 1,500 per ton
  to install

http//www.eren.doe.gov/geothermal/geobasics.html
http//www.nrel.gov/data/pix/searchpix.cgi?getrec
3297896display_typeverbose
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• This house in Aurora, Colorado, uses a geothermal
  heat pump system that will provide al the
  heating, cooling, and hot water needs. For a home
  of 1,500 square feet with a good building
  envelope and a geothermal heat pump, energy costs
  are about 1 a day.

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Cost Comparison, Gwinnet, GA

• Heating and Cooling Components
• 3-ton Addison heat pump, 15 kW auxiliary heat
  Closed loop Central thermostat
• Installation Costs
• 4,700 increment over comparable system 3,600
  indoor hard costs 2,766/ton 1,800/house
  incentive from Jackson EMC
• Operating Costs (air source/water source)
• Heating 307/211 Cooling 252/230 Water
  heating 270/136 Annual total 1,073/577
  5.84-year payback to recover 2,900

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Benefits of a GHP System

• Low Energy Use
• Free or Reduced-Cost Hot Water
• Year-Round Comfort
• Low Environmental Impact
• Durability
• Reduced Vandalism
• Zone Heating and Cooling
• Low Maintenance

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Solar Heating and Cooling

• Most American houses receive enough solar energy
  on their roof to provide all their heating needs
  all year!
• Active Solar
• Passive Solar

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Passive Solar

• A passive solar system uses no external energy,
  its key element is good design
• House faces south
• South facing side has maximum window area (double
  or triple glazed)
• Roof overhangs to reduce cooling costs
• Thermal mass inside the house (brick, stones or
  dark tile)

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Passive Solar

• Deciduous trees on the south side to cool the
  house in summer, let light in in the winter.
• Insulating drapes (closed at night and in the
  summer)
• Greenhouse addition
• Indirect gain systems also such as large concrete
  walls to transfer heat inside

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Passive Solar Heating
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Source Global Science, Energy Resources
Environment
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Active Solar Heating

• Flat plate collectors are usually placed on the
  roof or ground in the sunlight.
• The sunny side has a glass or plastic cover.
• The inside space is a black absorbing material.
• Air or water is pumped (hence active) through the
  space to collect the heat.
• Fans or pumps deliver the heat to the house

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Active Solar Heating
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Flat Plate Collector

• Solar Collectors heat fluid and the heated fluid
  heats the space either directly or indirectly

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Efficiency of Furnace

• The "combustion efficiency" gives you a snapshot
  in time of how efficient the heating system is
  while it is operating continuously
• The "annual fuel utilization efficiency" (AFUE)
  tells you how efficient the system is throughout
  the year, taking into account start-up,
  cool-down, and other operating losses that occur
  in real operating conditions.
• AFUE is a more accurate measure of efficiency and
  should be used if possible to compare heating
  systems.

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Efficiencies of Home Heating
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Tips (Individual) to Save Energy and Environment

• Set your thermostat as low as is comfortable in
  the winter and as high as is comfortable in the
  summer.
• Clean or replace filters on furnaces once a month
  or as needed.
• Clean warm-air registers, baseboard heaters, and
  radiators as needed make sure they're not
  blocked by furniture, carpeting, or drapes.
• Bleed trapped air from hot-water radiators once
  or twice a season if in doubt about how to
  perform this task, call a professional.
• Place heat-resistant radiator reflectors between
  exterior walls and the radiators.

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• Use kitchen, bath, and other ventilating fans
  wisely in just 1 hour, these fans can pull out a
  houseful of warmed or cooled air. Turn fans off
  as soon as they have done the job.
• During the heating season, keep the draperies and
  shades on your south-facing windows open during
  the day to allow sunlight to enter your home and
  closed at night to reduce the chill you may feel
  from cold windows. During the cooling season,
  keep the window coverings closed during the day
  to prevent solar gain.

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• Close an unoccupied room that is isolated from
  the rest of the house, such as in a corner, and
  turn down the thermostat or turn off the heating
  for that room or zone. However, do not turn the
  heating off if it adversely affects the rest of
  your system. For example, if you heat your house
  with a heat pump, do not close the ventsclosing
  the vents could harm the heat pump.
• Select energy-efficient equipment when you buy
  new heating and cooling equipment. Your
  contractor should be able to give you energy fact
  sheets for different types, models, and designs
  to help you compare energy usage. Look for high
  Annual Fuel Utilization Efficiency (AFUE) ratings
  and the Seasonal Energy Efficiency Ratio (SEER).
  The national minimums are 78 AFUE and 10 SEER.