New Standard Showcases Efficiency of VRF Multi-Splits

The Air-Conditioning. Heating and Refrigeration Institute (AHRI) has for the first time created a standard to compare the efficiency of variable refrigerant flow (VRF) multi-split heating and cooling systems. The standard, AHRI 1230-2010, creates testing procedures for VRF multi-split systems, including those with variable-speed compressors. It covers VRF air conditioners and heat pumps using distributed refrigerant technology with heating and cooling capacities for outdoor units from 12,000 to 300,000 Btu/hr (3,500–90,000 W) and indoor units from 5,000 to 60,000 Btu/hr (1,000–20,000 W), with indoor units conditioning a single zone.

Because VRF multi-split systems come in a wide variety of configurations and often operate at variable speeds, assessing their efficiency and comparing them with other cooling systems has been difficult (see “Ductless Mini-Splits and Their Kin: The Revolution in Variable-Refrigerant-Flow Air Conditioning,”

EBN Aug. 2008). “There were no standards in the system when we brought VRFs in seven years ago,” said Paul Doppel, director of government affairs at Mistubishi. “We had to show how to test with variable- speed compressors and multiple indoor units,” he continued. Doppel, along with other industry representatives, worked with the U.S. Department of Energy to develop the standard.