An issue of great interest to electric utilities is how HVAC equipment may interact with the electric grid under different scenarios. As utilities investigate various methods of regulating the grid for efficiency and reliability purposes, it is critical to understand how end-use devices such as air conditioners and heat pumps will respond. Conservation Voltage Reduction (CVR) refers to management of service voltage for the purpose of reducing energy consumption. Many electric distribution utilities are either implementing or planning to implement (CVR) as a mechanism to promote energy conservation and improve the overall efficiency of the electric distribution system. The biggest unknown for evaluating the impact of CVR is the response of different types of loads to voltage reduction. Split-unit residential air conditioners are by far the most important piece of equipment in determining the overall impact of CVR. On the other hand, these air conditioners have a complex relationship between energy consumption and voltage due to thermostatic control and large thermal time constants which makes quantifying the impact of CVR a very challenging task. In order to address this challenge, Electric Power Research Institute (EPRI) tested two residential heat pumps in cooling as well as heating modes. The systems were tested with power supply voltages ranging from 0.8 to 1.05 per unit voltage on 240V base voltage. Measurements of air-side capacity and system power were used to quantify system performance across this range of conditions. This paper summarizes the testing efforts and the results obtained. The work presented in this paper can be used in modeling tools to quantify response of residential air conditioners to evaluate the performance of a distribution system operation with a CVR scheme. Also, the results of this study will help inform the HVAC industry, and may help improve system designs should CVR find broad adoption.
Citation: ASHRAE Papers CD: 2014 ASHRAE Annual Conference, Seattle, WA
Product Details
- Published:
- 2014
- Number of Pages:
- 8
- File Size:
- 1 file , 1.1 MB
- Product Code(s):
- D-SE-14-C069
