Research >> 1. Energy Saving from HVAC System >>Energy saving from GHP system


■ Energy Saving from GHP System


□ Energy Saving of Buildings and Community

 A lot of Researches on energy saving of buildings and community are conducted to optimize building systems operation. Especially recently a research project on energy saving of buildings during operation is started by the International Energy Agency, which cause much attention all over the world. Although the energy saving in buildings is implemented since the energy crisis, it is mainly considered during design phase and how to design a energy-efficient building is the main topic.However, during actual operation, many energy saving measures do not act as design intent, and many issues that were considered during design phase take place. Such kind of problem was realized recently and it is considered that 20% - 30% energy can be saved if these problems can be solved.



Figure-1 System image



□ Commissioning Method for GHP(Gas-engine Heat Pump) System and Its
 Verification

Purposes of This Study
Building commissioning is the process of ensuring that building systems are designed, installed, functionally tested, and capable of being operated and maintained to perform in conformity with the design intent. Commissioning is considered to be an effective method to ensure the performance of energy saving measures.
 This research focuses on developing a model-based commissioning method for GHP air-conditioning system.



Figure-2 GHP system



Results of This Study
This research focuses on developing model-based commissioning method for Gas-engine Heat Pump (GHP) air-conditioning systems.
 1) The accuracy of heating/cooling load simulation, which is used for commissioning is verified using measurement.
 Four methods are used to calculate heating/cooling load, 1) using measured heat flow, 2) using measured air temperature and humidity at the inlet and outlet air-conditioners, 3) using measured refrigerant temperature and pressure , 4) using simulation. The difference between simulation and measurement is within 20%.
 2) A model estimating air-conditioner filter resistance is developed. Two sorts of value are used as inputs to estimate filter resistance. One is the power consumed by the fan in the indoor unit and the other is the thermal performance. For the room air-conditioners that the real time indoor unit fan power consumption is available, fan power consumptions are used as inputs to estimate filter resistance. For the room air-conditioners that are equipped with refrigerant pressure and temperature sensors, this model estimates filter resistance using refrigerant pressure and temperature, air temperature or enthalpy difference between supply and indoor air. The maximum and average difference between estimated and measured filter resistance are 12.72% and 5.89% when using the fan power consumption as inputs. When using the air-conditioner thermal performance data, the maximum and average estimation errors are13.12% and 5.96%. Based on this model, the method for commissioning filters in air-conditioner is discussed.



Figure-3 Scene of Measurement 1

Figure-4 Scene of Measurement 2