24
Answer:
New Rating
= 297 gal/hr x (180,000 BTU/h)/(220,000 BTU/h)
= 297 gal/hr x 0.818 = 243 gal/hr
NOTICE
Increasing the boiler DOE heating capacity above the
values listed in Table 3 will not increase the rating of the
water heater.
Ratings are based on 200°F boiler water. If 180°F boiler
water is supplied, First Hour and Continuous Draw ratings
will be reduced by approximately 27%.
2. Circulator Sizing – Refer to Table 4 for the
corresponding pressure drop through the coil for the
given model. Calculate the pressure drop of all straight
pipe and fittings on the supply and return of the water
heater at the selected flow rate. Add the piping/fitting
pressure drop to the pressure drop through the water
heater coil.
Select a circulator that will provide an appropriate flow
rate at the combined pressure drop.
The Single-wall Indirect water heater must be installed as a zone
separate from the space heating system. The domestic hot water
zone’s piping and circulator must be sized for a minimum flow rate
with all zones in use and a maximum flow rate with only the water
INTERNET VERSION FOR REFERENCE ONLY