Compare Energy Use in Variable Refrigerant Flow Heat Pumps Field Demonstration and Computer Model
Variable Refrigerant Flow (VRF) heat pumps are often regarded as energy efficient air-conditioning systems which offer electricity savings as well as reduction in peak electric demand while providing improved individual zone setpoint control. One of the key advantages of VRF systems is minimal duct losses which provide significant reduction in energy use and duct space. However, there is limited data available to show their actual performance in the field. Since VRF systems are increasingly gaining market share in the US, it is highly desirable to have more actual field performance data of these systems. An effort was made in this direction to monitor VRF system performance over an extended period of time in a US national lab test facility. Due to increasing demand by the energy modeling community, an empirical model to simulate VRF systems was implemented in the building simulation program EnergyPlus. This paper presents the comparison of energy consumption as measured in the national lab and as predicted by the program. For increased accuracy in the comparison, a customized weather file was created by using measured outdoor temperature and relative humidity at the test facility. Other inputs to the model included building construction, VRF system model based on lab measured performance, occupancy of the building, lighting/plug loads, and thermostat set-points etc. Infiltration model inputs were adjusted in the beginning to tune the computer model and then subsequent field measurements were compared to the simulation results. Differences between the computer model results and actual field measurements are discussed. The computer generated VRF performance closely resembled the field measurements.
- Research Organization:
- Univ. of Central Florida, Orlando, FL (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDOE EE Office of Building Technologies (EE-2J)
- Contributing Organization:
- Florida Solar Energy Center
- DOE Contract Number:
- EE0003848
- OSTI ID:
- 1093846
- Report Number(s):
- DOE-EE0003848-DE-13-C072
- Resource Relation:
- Conference: ASHRAE Annual Meeting, Denver, CO, June 2013
- Country of Publication:
- United States
- Language:
- English
Similar Records
Computer Modeling VRF Heat Pumps in Commercial Buildings using EnergyPlus
Predictive Optimal Control of Active and Passive Building Thermal Storage Inventory