Gas fired water heaters shall conform to ANSI Z21.10.1 when input is 22 kW
75,000 Btu/hour or less or ANSI Z21.10.3 for heaters with input greater
than 22 kW 75,000 Btu/hour. [A phenolic resin coating shall be provided.]
2.13.1.3
Electric Type
Electric type water heaters shall conform to UL 174 and have dual heating
elements. Each element shall be 4.5 kW 3,000 Btu/hour. The elements shall
be wired so that only one element can operate at a time. [A phenolic resin
coating shall be provided.]
2.13.1.4
Indirect Heater Type
**************************************************************************
NOTE: The title of the sections covering the
applicable systems will be inserted in the blanks.
Cast-iron heads will be used in steam-to-steam or
nonfired boiler application. Bronze heads will be
used in steam-to-water application. Carbon steel
heads will be used in water-to-water applications.
For most applications, copper coils will be
acceptable. Copper-nickel coils will be used with
high pressure steam, 1.034 MPa (150 psi) or above,
high temperature water, or salty water conditions.
Single wall type exchangers may be allowed if the
requirements in the plumbing code are satisfied (one
requirement is that the heat transfer medium is
potable or recognized as safe).
**************************************************************************
Steam and high temperature hot water (HTHW) heaters with storage system
shall be the assembled product of one manufacturer, and be ASME tested and
"U" stamped to code requirements under ASME BPVC SEC VIII D1. The storage
tank shall be as specified in paragraph HOT-WATER STORAGE TANKS. The heat
exchanger shall be [double wall] [single wall] type that separates the
potable water from the heat transfer medium with a space vented to the
atmosphere in accordance with ICC IPC. [The coil shall be coated as
specified in paragraph Water Heater, Phenolic Resin Coatings.]
a.
HTHW Energy Source: The heater element shall have a working
pressure of 2758 kPa 400 psig with water at a temperature of 204
degrees C 400 degrees F. The heating surface (see 6.2 and 6.8)
shall be based on 0.093 square meter 1 square foot of heating
surface to heat 76 L 20 gallons or more of water in 1 hour from 4
to 82 degrees C 40 to 180 degrees F using hot water at a
temperature of 178 degrees C 350 degrees F. Carbon steel heads
shall be used. Tubing shall conform to ASTM B 111/B 111M, Copper
Alloy No. 706 (90-10 copper-nickel). Heating elements shall
withstand an internal hydrostatic pressure of 4137 kPa 600 psig
for not less than 15 seconds without leaking or any evidence of
damage.
b.
Steam Energy Source: The heater element shall have a working
pressure of 1034 kPa/square meter 150 psi gauge (psig) with steam
at a temperature of 185 degrees C 365 degrees F. The heating
surface (see 6.2 and 6.8) shall be based on 0.093 square meter 1
SECTION 15405A
Page 51
Previous Page
