This section summarizes the changes to the requirements for residential water heating for the 2016 Standards.
1. Isolation valves must be installed on instantaneous water heaters that have an input rating greater than 6.8 kBTU per hour (2 kW). The valves must be installed on the cold water line leading to the water heater and the hot water line leaving the water heater. As discussed in Section 5.2.3 of this chapter, manufacturers recommend flushing the heat exchanger in instantaneous water heaters. Isolation valves simplify this routine maintenance practice, which reduces the cost and burden of maintaining the water heater.
2. Storage water heaters do not need to have blankets anymore. The 2013 Standards required storage water heaters with efficiency levels equivalent to the minimum federal efficiency standard to be externally wrapped (i.e. water heater blanket) with insulation of R-12 or greater. This requirement has been deleted. With the amended federal standards that went effect on April 16, 2015, insulation of water heater storage tanks is no longer cost effective.
3. For alterations all newly installed hot water piping and existing accessible piping must be insulated if installing new piping at the time an existing water heater is replaced (i.e. replacement water heating systems).
The prescriptive requirements for single family buildings and multi-family buildings with a dedicated water heater in each dwelling unit have been updated. Note that a single dwelling unit is defined as a residence with its own water heater. Use of the term pertains to both a single family home and a unit (e.g., apartment) within a multi-family building that has a dedicated water heater.
The 2016 prescriptive requirements for single family buildings and multi-family buildings with a dedicated water heater in each dwelling unit are as follows:
Option 1: Install a natural gas or propane instantaneous water heater that meets the minimum requirements in California’s Title 20 Appliance Efficiency Regulations, Section 1605.1(f) for federally-regulated appliances.
Option 2: Install a natural gas or propane storage water heater with a rated storage volume of 55 gallons or less that meets the minimum requirements in California’s Title 20 Appliance Efficiency Regulations Section 1605.1(f) for federally-regulated appliances. In addition, the building must comply with the HERS verified Quality Insulation Installation (QII) requirements (see Chapter 3, Section 3.6.3.4(B) of the Compliance Manual) as well as one of the following requirements:
1. HERS Verified Pipe Insulation (see Reference Appendix RA 3.6, RA4.4.1, RA4.4.3 and RA4.4.14 for the requirements of proper installation of pipe insulation and Section 5.6.2.5 of the Compliance Manual); or
2. HERS Verified Compact Hot Water Distribution Design (see Reference Appendix RA 3.6 and RA4.4.16 for requirements and Section 5.6.2.4 of the Compliance Manual);
Option 3: Install a natural gas or propane storage water heater with a rated storage volume over 55 gallons and an input rating of 105,000 Btu/hr or less. The water heater must meet the requirements in California’s Title 20 Appliance Efficiency Regulations Section 1605.1(f) for federally-regulated appliances. In addition, the building must comply with one of the following:
1. HERS Verified Pipe Insulation; or
2. HERS Verified Compact Hot Water Distribution Design.
There is no longer a prescriptive option that allows electric water heating. Users that wish to use electric water heating can comply with the Standards using the performance approach.
1. The water heating energy budget is now based on the energy performance of a natural gas instantaneous water heater that meets the minimum requirements in California’s Title 20 Appliance Efficiency Regulations Section 1605.1(f) for federally-regulated appliances.
2. The Point of Use Distribution credit no longer requires HERS verification.