Safety question: understanding powerventing

A question about using a powervented flue instead of a traditional chimney. Perhaps it is due to my perhaps limited understanding of the way a powervented appliance works, bit I would greatly appreciate an explanation please. For instance in a gas or oil boiler, the powerventer operates when the boiler fires, venting exhaust gases.

However in a coal stoker, the pile of coal within continues to smolder and burn, even if the boiler is not "firing". Therefore:

1. How is the matter of exhaust gases when the boiler is not firing dealt with? The continuously smoldering pile of coal requires venting, which in a traditional flue, relies on the natural draft present to evacuate flue gases. How is this dealt with in a powervented situation? Is the powerventer continuously running or does it operate on a timed schedule, every few minutes?

2. In an electrical outage, the pile of coal will continue to smolder, yet no electricity is available to operate the powerventer and thus evacuate flue gases. What is the method of dealing with this situation?

Powervent is always on in a coal install...
Powervent is only used on coal stokers not hand fired with large amounts of coal in them...

The amount of rice coal on a flat bed stoker is pretty small so if the power goes out...
Not much to burn out...

Yes, Power venter is ON all the time. I have been running my Keystoker 90K stove (in the winter) for 6 years now with a direct vent.

Once the power goes out, your fire will go out since the Stoker type stoves or boilers need a "combustion "blower to keep the fire going. The stove is pretty sealed, so the fumes will just migrate out the pipe even though the power vent is not on.

2 Terms for them.
Power vents typically mount on the outside wall and suck the fumes out of the stove, typically a 6" pipe.

Direct Vents are typically mounted to the stove and push the fumes out, advantage, smaller pipe (4") but pipes must be sealed.

If you do a search on here.....

Direct vent vs Power vent...

Direct vs power vents.

Direct Vent Question

Thank you for the replies.