Does anyone have any experience on the cold weather heating performance of mini splits, especially if a backup heat source is not provided?
The mini-splits are typically rated as having a rated or nominal heating output at 47F and 17F Dry Bulb per AHRI 210/240. For the sake of discussion a Mitsubishi FE12NA has a stated output rating range at 47F of 3K-21KBTU with a rated capacity of 13,600. What is the difference between "maximum" and "rated"? Is "maximum output" attainable if needed for days or only available for short term as in hours?
A few of the systems claim they can provide close to 100% of (max?) capacity at 5F such as the Mitsubishi FE12 models (with hyper heating) and they claim max of 13,600 at 17F and 12,500 at 5F. But there again the "rated" capacity is 8,300 at 17F, not the 13,600 that they state is maximum.
Is "hyper-heating" just a marketing gimmick that allows them to claim a rated maximum output but is not really a usable output? They also claim heat output at -13F is about 58% although no output is provided. The correction factor for defrost is not included.
Any experience with how Mitsubishi compares with other brands such as the Fujitsu high efficiency single configurations such as 12RLS? Fujitsu does not rate theirs at 5F.