17
Pre-installation continued-
DOMESTIC HOT WATER PRIORITY
Two options are available, Priority and Non-Priority.
1.
Priority –
Demand for space heating is interrupted or postponed
until the domestic hot water demand is satisfied. This option
provides maximum delivery of domestic hot water. Priority is
recommended when:
a) Boiler net output is 100,000 Btu per hour or less, or
b) When boiler output required to satisfy domestic hot water
demand is at least 50% of the boiler output required to satisfy
space heating demand, or
c) When an interruption in space heating can be tolerated during a
long domestic hot water draw.
2.
Non-Priority –
Boiler output is divided between space heating
and domestic hot water heating. Delivery of domestic hot water
can be reduced during simultaneous space and domestic hot water
heating operations, depending on such factors as boiler output,
boiler over-sizing, number of space heating zones calling for heat,
and the ratio of domestic hot water load to space heating load.