Commercial boilers

SlamDunk

We have several hps boilers and i noticed all flue dampers are 100% open. Is there a reason? The start up techs never looked at them. I was wondering if we are losing energy doing this.

EBEBRATT-Ed

@slamdunk, I am assuming that "hps boilers" means high pressure steam.

In any event, any boiler that has a damper in the flue the damper must be locked in the open position or if it's a motorized damper it must be driven open and proven open electrically before the burner can fire. If a damper is partially closed to restrict excessive draft at the boiler then it must be locked in position after combustion testing.

Something used widely in the past but not used as often now is "sequence draft control". These controls were usually made by "Cleveland Controls" or "Preferred Utilities" and used a damper actuator and controller to close the damper on the off cycle. Open it when the burner fired and operate automatically "float" to control the draft as the burner modulated from low to high fire. Not seen much any more.

SlamDunk

yes. high pressure steam.

Thanks! they are locked 100% open. I was wondering why they were installed but not used.

the_donut

Maybe to avoid a service call later when the dampers fail closed.

EBEBRATT-Ed

@SlamDunk

What kind of boilers are they? Pressure fired forced draft? or natural draft?

SlamDunk

forced draft. pipe straight to roof about 36’. burner has blower