C406.2.6
Reduced
energy use in service water heating. Buildings with service hot water
heating equipment that serves the whole building, building addition or tenant
space shall achieve credits through compliance with:
1. Section C406.2.6.1, C406.2.6.2, or
C406.2.6.3.
2. Sections C406.2.6.1
and C406.2.6.2.
3. Sections
C406.2.6.1 and C406.2.6.3.
C406.2.6.1
Shower drain heat
recovery. Shower drain heat recovery units shall comply with Section
C404.10 and preheat cold water supply to the showers. Potable waterside
pressure loss shall be less than 10 psi (69 kPa) at maximum design flow. The
efficiency of drain water heat recovery units shall be 54 percent in accordance
with CSA B55.1. Full credits are applicable to the following building use
types: Multi-family, hotel, motel, dormitory, and schools with locker room
showers. Where not all showers in the project have drain heat recovery, the
credit is adjusted based on the following:
[Section C406.2.6.1 table credits] x [Showers with drain
recovery] / [Total number of showers]
C406.2.6.2
Service water heating energy
recovery. Not less than 30 percent of the annual service hot water
heating energy use, or not less than 70 percent of the annual service hot water
heating energy use in buildings with condenser water systems subject to the
requirements of Section C403.9.2.1 or qualifying for one of its exceptions,
shall be provided by one or more of the following:
1. Waste heat recovery from service hot
water, heat recovery chillers, building equipment, process equipment, or other
approved system. Qualifying heat recovery must be above and
beyond heat recovery required by other sections of this code.
2. On-site renewable energy water-heating
systems where not used to meet other requirements or to obtain other energy
credits.
C406.2.6.3
Heat pump water heating. Projects shall achieve credits through
compliance with Section C406.2.6.3.1.
C406.2.6.3.1
Heat pump water
heater. Credit shall be achieved where the primary heat pump service
water heating system is sized to deliver no less than 100 percent of the net
calculated demand for service water production during the peak demand period
with entering dry bulb or wet bulb outdoor air temperature at 40°F
(4°C) for air-source heat pumps, or 44°F (7°C) ground temperature
for ground-source heat pumps, as calculated using the equipment manufacturer's
selection criteria or another
approved methodology. For this
credit, the net calculated demand shall be the gross building demand less any
portion of the demand complying with the exceptions to Section C404.2.1.
Supplemental heating is permitted in accordance with Section C404.2.1, but
cannot use fossil fuels. Heat pump water heaters shall comply with one of the
following:
1. The COP rating shall be a
minimum COP of 3.0 reported at the design leaving heat pump water temperature
with an entering air temperature of 60°F (16°C) or lower. For
water-source equipment, the COP rating will be reported at the design leaving
load water temperature with an entering load water temperature of 74°F
(23°C) or lower.
2. The uniform
energy factor (UEF) shall be a minimum of 3.40 rated based on U.S. Department
of Energy requirements.
C406.2.6.4
High efficiency service
water heating, gas-fired. The credit achieved shall be from Table
C406.2(2) where hot water is supplied by gas-fired equipment with minimum
efficiency of 0.91 UEF.
C406.2.7
Improved service hot water
temperature maintenance. For buildings with gross floor area greater
than 10,000 square feet, credit shall be achieved when hot water temperature
maintenance is installed in accordance with Section C406.2.7.1 or C406.2.7.2.
C406.2.7.1
Self-regulated heat trace
system. The credit achieved shall be from Table C406.2(1). This system
shall include self-regulating electric heat cables, connection kits and
electronic controls. The cable shall be installed directly on the hot water
supply pipes underneath the insulation to replace standby losses.
C406.2.7.2.
Point of use water
heater. The credit achieved shall be from Table C406.2(1) where any
fixtures requiring hot water shall be supplied from a localized electric source
of hot water with no recirculation or heat trace and limited to 2 kW and 6
gallons of storage. The supply pipe length from the point of use water heater
to the termination of the fixture supply pipe shall be no more than 20
feet.
C406.2.8
Service hot water distribution right sizing. To achieve this
credit, where Group R-1 and R-2 occupancies are served by a central service hot
water system, the distribution system serving dwelling units,
sleeping units and guestrooms shall be sized using Appendix M
of the Uniform Plumbing Code.
C406.2.9
High performance service hot
water temperature maintenance system. Systems with multiple riser
service hot water circulation systems shall use only heat pump technology for
temperature maintenance. The heat pump technology shall have a minimum COP of
3.0 or UEF of 3.4. For air-source equipment, the COP rating will be reported at
the design leaving heat pump water temperature with an entering dry bulb air
temperature of 60°F (16°C) or lower and a relative humidity of 50
percent or lower. For water-source equipment, the COP rating will be reported
at the design leaving load side water temperature with an entering source side
water temperature of 74°F (23°C) or lower. The system shall comply with
the requirements of Section C404.7.1.
C406.2.10
High efficiency service hot
water circulation system. Multiple riser service hot water circulation
systems shall use a variable volume circulation pump controlled to vary the
pump speed based on system demand and shall include self-actuated thermostatic
balancing valves to control the system flow at each riser.
C406.2.11
Low flow showerheads for
Group R-1 and R-2 occupancies. All showerheads installed in Group R-1
and R-2 dwelling units or sleeping units
shall have a maximum listed flowrate of 1.25 gallons per minute or less at 80
psi operating pressure for fixed showerheads and a maximum listed flowrate of
1.50 gallons per minute or less at 80 psi operating pressure for handheld
showerheads. When a shower is served by more than one showerhead, including
handheld showerheads, the combined flow rate of all showerheads and/or other
shower outlets controlled by a single valve shall not exceed 1.25 gallons per
minute or less for fixed or 1.5 gallons per minute or less for handheld, or the
shower shall be designed to allow only one shower outlet to be in operation at
a time.