Code Cycle: 2016 & 2019 Standards
Reference: CalCERTS New Construction Training Manual Chapter 5, Section 5
HERS Point of Use
A point-of-use distribution system design significantly reduces the volume of water between the water heater and the hot water use points. Use of this type of system requires a combination of good architectural design (that is, water heater location adjacent to hot water use points), an indoor mechanical closet, or the use of multiple water heaters. Figure 5-10 provides an example of the latter approach where three water heaters are installed close to the use points. This system is not applicable to systems serving multiple dwelling units.
Installation Criteria and Guidelines
All applicable mandatory features must be met, and the distance between the water heater and any fixture using hot water cannot exceed the length specified in Table 5-10 below. The adopted requirements for installation guidelines are included in RA4. All water heaters and hot water fixtures must be shown on plans submitted for a local building department plan check.
HERS Verification: RA4.4.5
This measure requires that all hot water fixtures in the dwelling unit, with the exception of a stand-alone tub must use no more pipe per run than defined in Table 4.4.5. To meet this requirement most houses will require multiple water heaters.
(a) Measurements shall be made to the nearest half foot.
(b) If a combination of piping is used in a single run then one half the allowed length of each size is the maximum installed length.
(c) The hot water distribution system piping from the water heater(s) to the fixtures and appliances must take the most direct path. For example, in a house with more than 1-story and the water heater in the garage, this requirement would exclude running hot water supply piping from the manifold to the attic, and then running the line back down to a first floor point of use.
(d) Hot water piping shall be insulated to a level that meets the requirements of 150.0(j) and be installed in accordance with Proper Installation of Pipe Insulation RA4.4.1, See article titled "2016 & 2019 HERS Residential Hot Water Distribution Pipe Insulation Requirements."