Sustainable Energy

  • Y. H. Venus LunEmail author
  • S. L. Dennis Tung
Part of the Green Energy and Technology book series (GREEN)


There are many factors to study in designing sustainable heat pump systems. Among them, the loading calculation dictates the system’s equipment selection. Calculating the loading demand for equipment sizing and selecting high-performance system are important in the process to plan for sustainable energy system. When sizing a heat pump, it is essential to determine the required cooling and heating capacity. To begin, this chapter examines factors affecting the heating/cooling demand for indoor thermal comfort. Key variables of thermal comfort are also discussed. To further investigate energy efficiency, coefficient of performance (COP) is examined. There are several methods that exist in determining COP. Equations and methods to determine COP are investigated. Examples of COP calculation on water-to-water heat pump and air-to-water heat pump are illustrated. The findings indicate that the COP level varies with types of heat pumps.


Load calculation Thermal comfort Balance point temperature Heating capacity Cooling capacity Coefficient of performance 


Seasonal energy efficiency ratio


Seasonal energy efficiency ratio


Reference annual cooling demand


Annual electricity consumption






Nomenclature: Fanger’s comfort equation


Thermal resistance of clothing


Rate of metabolic rate production


Water vapor pressure


Mean radiant temperature


Air temperature


Relative air velocity

Nomenclature: Heating and Cooling Capacity


Specific heat at constant pressure, expressed in joules per kilogram and kelvin


Energy balance


Energy into a system


Energy out of a system


Mass flow rate


Cooling capacity, expressed in watts


Heating capacity, expressed in watts


Heat recovery capacity, express in watts


Volume flow rate, expressed in cubic meters per second


Density, expressed in kilograms per cubic meter


Difference between inlet and outlet temperatures

Nomenclature: Coefficient of Performance (COP)


COP of cooling


COP of heating


COP of heating and cooling


Capacity of condenser (for heating)


Capacity of evaporator (for cooling)


Capacity of heat recovery of condenser (for heating)


Total input power


Enthalpy in front of the compressor


Enthalpy behind the compressor


Enthalpy at the injection valve


  1. 1.
    European Commission (2016) Overview of support activities and projects of European Union and energy efficiency and renewable energy in the heating and cooling. European UnionGoogle Scholar
  2. 2.
    British Standard (BS EN 14522-1) (2013) Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling. BSI Standards PublicationGoogle Scholar
  3. 3.
    Burdick A (2011) Strategy guideline: accurate heating and cooling load calculations. U.S. Department of Energy (Building Technologies Program)Google Scholar
  4. 4.
    Robin R (2010) Getting warmer: a field trial of heat pumps. The Energy Saving TrustGoogle Scholar
  5. 5.
    Li Y, Cheng Z (2003) A balance-point method for assessing the effect of natural ventilation on indoor particle concentrations. Atmos Environ 37:4277–4285CrossRefGoogle Scholar
  6. 6.
    En 14825 (2016) Air conditioners, liquid chilling packages and heat pumps, with electrically driven compressors, for space heating and rating at part load conditions and calculation of seasonal perform. British StandardGoogle Scholar
  7. 7.
    ANSI/ASHARE Standard 55 (2014) Thermal environment conditions for human occupancyGoogle Scholar
  8. 8.
    Hensen JLM (1990) Literature review on thermal comfort in transient condition. Build Environ 25(4):309–316CrossRefGoogle Scholar
  9. 9.
    Ekici C (2013) A review of thermal comfort and method of using Fanger’s PMV equation. In: 5th International symposium on measurement, analysis and modelling of human functions. Vancouver, CanadaGoogle Scholar
  10. 10.
    Fanger PO (1970) Thermal comfort, analysis and application in environmental engineering. Danish Technical Press, CopenhagenGoogle Scholar
  11. 11.
    Noel D, Rene T, Donatien N (2010) Thermal comfort: a review paper. Renew Sustain Energy Rev 14:2626–2640CrossRefGoogle Scholar
  12. 12.
    Dear RJ (2002) Thermal comfort in naturally ventilated buildings: revisions to ASHARE Standard 55. Energy Build 34(6):549–561CrossRefGoogle Scholar
  13. 13.
    Kwok A, Rakovich NB (2010) Addressing climate change in comfort standards. Build Environ 45:18–22CrossRefGoogle Scholar
  14. 14.
    Mui K, Chan W (2003) Adaptive comfort temperature model of air-conditioned building in Hong Kong. Build Environ 38:837–852CrossRefGoogle Scholar
  15. 15.
    Schiavon S, Melikov AK (2008) Energy saving and improved comfort by increased air movement. Energy Build 40:1954–1960CrossRefGoogle Scholar
  16. 16.
    Cheng CC, Lee D (2016) Enabling smart air conditioning by sensor development: a review. Sensors 16(12):2028. Scholar
  17. 17.
    British Standard (BS EN 14522-3) (2013) Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling. BSI Standards PublicationGoogle Scholar
  18. 18.
    AHRI (550/590) (2015) Standard for performance rating of water-chilling and heat pump water-heating packages using the vapor compressor cycle. Air Conditioning Heating and Refrigeration InstituteGoogle Scholar
  19. 19.
    ASHARE Handbook (2017) Fundamentals 2.3Google Scholar
  20. 20.
    Shao S, Shi W, Li X, Ma J (2004) A new inverter heat pump operated all year round with domestic hot water. Energy Convers Manag 45:2255–2268CrossRefGoogle Scholar
  21. 21.
    Shao S, Shi W, Li X, Cheng H (2004) Performance representation of variable-speed compressor for invert air conditioners based on experimental data. Int J Refrig 27(8):805–815CrossRefGoogle Scholar
  22. 22.
    Bonin J (2016) Heat pump planning handbook. Routledge, LondonGoogle Scholar
  23. 23.
    Zogou O, Stamatelos A (1998) Effect of climatic conditions on the design optimization of heat pump systems for space heating and cooling. Energy Conserv Manage 39(7):609–622CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.Sustainable Energy LimitedHong KongPR China
  2. 2.Sustainable Energy LimitedHong KongPR China

Personalised recommendations