When the season starts, the Full-inverter HP runs at 100% capacity to heat up the pool in the first few days. After that, the Full-inverter HP runs at AVERAGE 50% capacity to maintain the desired pool temperature. Normally, the pool temperature drops 0.5~1.5℃ daily, 50% capacity of a Full-inverter HP is sufficient to heat the pool by 1.5~2.2℃ in 15 hours running with the right model selection. The AVERAGE COP 11.5 leads to half the running cost compared with an On/Off HP. Meanwhile, the AVERAGE sound pressure of a Full-inverter HP is 45.2 dB(A) at 1m, which is 10 times quieter than an On/Off HP and even can be negligible.