Slideshow Transcript

1. Slide 1: Heat Pumps
2. Slide 2: What is a heat pump?  A heat pump enables energy-efficient heating  It does not produce energy  It ‘pumps’ heat at a relatively lower temperature from air, water, or soil and gives it off at a higher temperature into a building www.leonardo-energy.org
3. Slide 3: Pros and Cons  Advantages – Lower life cycle cost due to high efficiency – Reduction of final energy demand by a factor 3 – Reduction of CO2 emissions by 25 – 65% (depending on baseline) – Business opportunity for contractors  Disadvantages – To be combined with low-temperature heating in a well- insulated building – High initial investment cost – Requires large soil surface or water volume (in case of a high efficiency water or soil heat pump) www.leonardo-energy.org
4. Slide 4: Basic principle (1/2) Principle is similar to refrigerator: Refrigerator: Heat pump: Heat is withdrawn from inside a Heat is withdrawn from refrigerator (low environment: air, soil, or temperature) water (low temperature) Temperature inside refrigerator Negligible temperature drop of drops the environment Extracted heat is given off to Extracted heat is given off into environment (higher building (higher temperature) temperature) Negligible temperature rise of Temperature of building’s the environment interior rises www.leonardo-energy.org
5. Slide 5: Basic principle (2/2) www.leonardo-energy.org
6. Slide 6: Four main components  Evaporator: – contains work fluid at lower temperature than environment. Heat is extracted from ground, air, or water. Pressure is low, so the work fluid evaporates  Compressor: – brings gas to higher pressure, the temperature rises  Condenser: – gas temperature is higher than fluid temperature of heating system. Excess heat is transferred to fluid. The gas cools and condenses  Pressure relief valve: – causes pressure reduction, the temperature drops, and the cycle begins again www.leonardo-energy.org
7. Slide 7: www.leonardo-energy.org
8. Slide 8: Also used for cooling  Has to be equipped with reverse valve to change circulation of the work fluid  This application is becoming popular www.leonardo-energy.org
9. Slide 9: High efficiency  To obtain 100% useful energy:  Traditional system on fossil fuel: – 120% combustion heat (paid for) – Coefficient of performance = 0.8  Heat pump: – 30% electrical energy to drive compressor (paid for); 70% taken from nature – Coefficient of performance = 3 www.leonardo-energy.org
10. Slide 10: Competitive life cycle cost www.leonardo-energy.org
11. Slide 11: Should be combined with low-temperature heating Lower temperature of heating fluid Compensated by larger heating surface  Large radiators  Floor heating  Wall heating  Ceiling heating (ideal in combination with reversible heat pump for cooling) www.leonardo-energy.org
12. Slide 12: Round-up  Transfers available heat from air, water, or soil at lower temperature into higher temperature for a building  Also used for cooling  High efficiency – Competitive life cycle cost – Lower environmental impact  Only effective in combination with low- temperature heating and adequate insulation  Investment cost is still high www.leonardo-energy.org
13. Slide 13: Further information  Heat Pump Centre: www.heatpumpcentre.org  Green Building: www.greenbuilding.com www.leonardo-energy.org