But there are some shortage of ordinary single-stage heat pump in low-temperature environment, such as high compression ratio, devoid heating power and low efficiency.
但普通单级空气源热泵热水器在低温环境下运行中存在压缩比过大、制热量不足和制热效率太低等问题。
2
FOUR-CYLINDER COMPRESSOR, air cooled, single effect, four-stagecompression.