Washington Administrative Code › Title 51 - Enterprise Services, Department of (Building Code Council) › Chapter 51-11C - State Building Code adoption and amendment of the 2021 edition of the International Energy Conservation Code, Commercial › Section 51-11C-40625 - Section C406.2.6-Service water measures

Current through Register Vol. 24-14, July 15, 2024
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.