that's the one thing about Delta I don't care for. When that fan first surfaced a few weeks ago, the Delta Web site didn't even mention it existed. My guess is that ThermoSonic buys them and ships the ThermoEngine with them. They may be a custom part and custom parts don't always show up on the discreet component markets. I stumbled upon some EBM turbine style 80mm DC fans. They are very good at pumping air, especially in a higher static pressure environment. The model is not documented anywhere as it was a special run for some equipment manufacturer, nor can you buy it on the open market. I hope that the "focused airflow" fan eventualy finds its way into the inventory of some of the stateside resellers, but I am not holding my breath. Look how long the Delta 80mm 69cfm fan, used on the MC-462A, took to become available as a discreet component.
Hoot