... bulb is 15C, and inlet water temp 15C, outlet water temp 55C. Test conditons:2.Low: Air source side inlet dry bulb is 7C ... , wet bulb is 6C, and inlet water temp 10C, outlet water temp 55C. 3.Super low: Air source side inlet dry bulb is -15C ... , wet bulb is -17C, and inlet water temp 10C, outlet water temp 55C. EVI Air Source Heat Pump Hot Water Radiator