IBC's approach to Ramp is different ?

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Dave Carpentier
Dave Carpentier Posts: 682
in THE MAIN WALL

I thought most boiler Ramp controls start off at a higher fire and then Ramp down. Better models have all sorts of tweaks to this.

On the IBC (with the V10 controller), the Ramp seems opposite ? (or maybe not)

"How fast the boiler tries to raise the water temperature flowing through the heat
emitters. …. You can manually set the Ramp Speed by choosing a value from 1 to 10. A setting of 1 will raise the water temperature very slowly and 10 will raise the water temperature very quickly."

Although there's no mention of it, I would assume it also backs off the burner % as it nears target. Maybe it's a matching fast/slow ramp there too ?

Does this seem like, if you set the Ramp to say "5", it's actually just capping the burner at 50% rate ? You can cap the overall boiler % rate in the main config, but maybe they also added it to each Load profile. Not sure if you end up with a % of a %.

On the other hand a Load could be variable (in-floor), so perhaps the burner% jumps all over to try and maintain a steady rate of temp increase ? (not just a % cap)

I'll probably start my in-floor / buffer tank at a "3" and the air handler Load at a 9 or 10. It's gonna take some playing.

30+ yrs in telecom outside plant.
Currently in building maintenance.

Comments

  • Jamie Hall
    Jamie Hall Posts: 27,911

    I don't know how that boiler does it — but there are two very distinct control philosophies to handle varying power requirements. One is to go full out to start, and then ramp down more or less rapidly as the setpoint is reached. The other, equally valid, is to ramp up and then slack back down as you reach the setpoint (often if there are adequate sensors the power output will be related to both how far off from setpoint you are, and how rapidly you are approaching it). They both have their benefits. (the alternate to either one is to go full out until you reach a setpoint and then drop way back or off — but if you have the option of proportional control, that's not a good approach).

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Dave Carpentier
    Dave Carpentier Posts: 682

    Found a table elsewhere on their web site. It says for all touchscreen boilers.

    Boiler V10 Ramp table.jpg

    You supply your own primary circ, and min/max flow for this boiler (VX-110) is 2-14 gpm.

    They dont specify an @flow rate, so it seems like the burn% can vary up/down to maintain the requested delta across the boiler (within it's burner capabilities of course) ?

    BTU/hr = 500 x gpm x ▲f

    At Ramp-3 and my primary circ flowing ~5.5gpm, this solves for 40kbtu. Very close to my design temp demand for the in-floor (50k). Close enough to try for the first year and wait to see what happens when it gets seriously cold out.

    30+ yrs in telecom outside plant.
    Currently in building maintenance.

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