Checking amp draw accumulations must be done with meters not by assumptions from reading an instruction book.
Inspiration cycle uses significantly more watts than expiration with a BiPap.
Use something like a Kil-A-Watt meter with the power brick connected to it. Multiply accumulated kWh fraction x 90% for a reasonable guess as to what to expect. A tubing insulation sleeve available from your medical supplier will SIGNIFICANTLY reduce humidifier accumulations because you will set the humidification to a much lower number.
(Above derived from experience not guesswork or assumptions)