Boiler Ratings & Capacities; Boilers For Use At High Altitude - Dunkirk Q90-50 Installation, Operation & Maintenance Manual

Model
90-50
90-75
90-100**
* 1 MBH = 1,000 Btuh
** 90-100 model is certifi ed for natural gas only.
++ AFUE (Annual Fuel Utilization Effi ciency) and Heating Capacity is based on the D.O.E. (Department of Energy) test
procedure.
Heating Capacity indicates the amount of heat available after subtracting losses up the stack. Most of this heat is available
to heat water. A small portion is heat from jacket and surfaces of the boiler, and it is assumed that this heat stays in the
structure.
Net AHRI rating represents portion of remaining heat that can be applied to heat radiation or terminal units (i.e. fi nned
tube baseboard, cast iron radiators, radiant fl oor, etc.). The difference between Heating Capacity and Net AHRI Rating,
called piping and pickup allowance, establishes reserve for heating volume of water in system and offsetting heat losses
from piping.
Net AHRI ratings shown are based on piping and pickup factor of 1.15 in accordance with AHRI Standard as published
by Hydronics Institute. Net AHRI rating of boiler selected should be greater than or equal to the calculated peak heating
load (heat loss) for building or area(s) served by boiler and associated hot water heating systems. Consult manufacturer
before selecting a boiler for installations having unusual piping and pickup requirements.
Boilers are factory equipped for operation at altitudes ranging from 0-5,000 feet above sea level (4,500 feet in Canada).

Boilers for use at high altitude

Canada - Contact Provincial authority having jurisdiction for installations above 4,500 feet (1,350m) above sea level.
United States - See "Boilers For Use At High Altitude" on page 6.
BOILER RATINGS & CAPACITIES
Table 1 - SEA LEVEL RATINGS – NATURAL AND PROPANE GASES
Input
++ Heating Capacity
*(MBH)
*(MBH)
50 45
75 68
100 90
Net AHRI Rating
*(MBH) Weight (lbs.)
39
59
78
Btuh = British Thermal Units Per Hour
5
Shipping
Flue Diameter
220 2" CPVC & PVC
220 2" CPVC & PVC
220 2" CPVC & PVC