9a. Home Heating Systems

1. 9a. Home Heating Systems

2. Heating Systems EGEE 102

3. Heating Systems • Some hot water systems circulate water through plastic tubing in the floor, called radiant floor heating. EGEE 102

4. 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) EGEE 102

5. 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/factsheets/geo_heatpumps.html#sidebar EGEE 102

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7. Geo Exchange Heat pump system Movie EGEE 102

8. World’s 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=3297896&display_type=verbose EGEE 102

9. 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. EGEE 102

10. 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 EGEE 102

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12. 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 EGEE 102

13. 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 EGEE 102

14. 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) EGEE 102

15. 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 EGEE 102

16. Passive Solar Heating EGEE 102

17. EGEE 102 Source: Global Science, Energy Resources Environment

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19. 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 EGEE 102

20. Active Solar Heating EGEE 102

21. Flat Plate Collector • Solar Collectors heat fluid and the heated fluid heats the space either directly or indirectly EGEE 102

22. 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. EGEE 102

23. Efficiencies of Home Heating EGEE 102

24. 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. EGEE 102

25. 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. EGEE 102

26. 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 vents—closing 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. EGEE 102