Many common software questions are answered in the categories below. If you can’t find a response for yours, try checking our User Forum, or, contact HelpDesk for direct assistance

MarketManager » Heating Equipment
Q: Why have part load ratios for boilers when they cycle on and off? Do they cycle on and work at less than full load, and then when load reaches a floor, they cycle off?


Indeed, boilers cycle on and off. The issue is that, if the PLR is, say, 50%, the boiler's duty cycle will generally be more than 50%. This is because as the boiler begins an on-cycle, much of the initial heat output is used just to heat up the heat exchanger, boiler jacket, and other thermal inertia. As the boiler cycle continues and the boiler reaches "steady state", its losses increase (since everything is hotter now), also wasting some additional heat. Finally, as the cycle ends (because the hot water has reached the upper setpoint throttling range), everything that had to be heated up at the beginning of the cycle is now nice and hot and has nowhere to go, i.e. is mostly lost in the intervening time until the next cycle begins.

I can’t find the answer to your question ? Try checking our User Forums.

Otherwise feel free to contact our Tech Support staff at (805) 329-6565, or via email at helpdesk@abraxasenergy.com.

MetrixMarketManagerReportMakerOption C