New mask and new machine, now I'm tired again

It might be your new machine's calibration is different than your original machine. You might have gotten used to that old machine. Just a few tenths of a CM of water decrease in pressure can make a huge difference in how you sleep and feel during the daytime.

If your old machine blew at an exact pressure of 8.1 and you slept on that for a couple years, your body gets used to that. If your "new and improved" machine blows at 7.8 even though the computer settings are the same, say a pressure of 8, that small decrease of .3 pressure can make you feel cruddy. Not everybody is this sensitive, but some are. Sleep doctors will usually pooh pooh that idea, btw.

Premium bipaps, like Resmed bipaps, are usually calibrated tighter btw than standard CPAPs and even premium APAPs. Hint hint. Some of the premium bipaps you can really dial in tight and exact. Resmed machines also can be dialed in tighter and more exact than Phillips Respironics and other machines that only adjust in .5 increments. Resmed adjusts in .2 increments and some of their bipaps even adjust in .1 increments.

Eric