A new AHRI study says the use of a bypass-type, single-stage cooling zone system in HVAC construction does not negatively affect the unit’s energy-efficiency ratio.

An engineering firm tested the performance of the zoned HVAC construction cooling system July 17, 2013. The results showed no negative impact on the cooling system’s efficiency due to the bypass airflow volume. The study actually showed a positive impact, the authors said. A second test 12 days later showed the same results.

"The data from this study will be valuable for manufacturers and contractors, and we are proud to have taken the lead on this important project," said Richard Foster, president of Trolex Corp. and chairman of the zone-control system technology project section.