Multi-split type air conditioning systems have become notably popular in recent years. When operating this system with excess air conditioning capacity, operation will generally be intermittent at a load factor of 25% or less. This means the room air temperature will undergo periodic fluctuations. The author conducted a subject-based experiment in a test chamber. It was found that many of the test subjects felt warm and uncomfortable while the room temperature was increasing during intermittent operation under a partial load. The subjects also felt cool and comfortable while the room temperature was dropping. While a distinguished difference was not found between “comfortable” and “uncomfortable” in the aggregate of the periodic reporting conducted every two minutes, a fairly clear difference was seen in impression reporting after the test, which indicated that intermittent air conditioning was more uncomfortable.