Appendix B - Boiler Altitude Derate Schedule - Patterson-Kelley P-K STORM ST-1250 Installation & Owner's Manual

Appendix B – Boiler Altitude Derate Schedule
For installations over 2,000 ft. elevations, a derate schedule is applied. The boiler input rating must be
reduced by 4% per 1,000 ft. which is illustrated in the graph below.
Although the appliance's capacity is reduced due to the lower air density, the combustion tuning should
follow the standard combustion guidelines of 3.11. Tune the combustion for the same O
levels as discussed in 3.11.2.
Revised: October 2, 2019
Released: October 2, 2019
 Patterson-Kelley 2019
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