Chapter 2 of this compliance manual addresses the compliance and enforcement process generally and discusses the roles and responsibilities of each of the major parties, the compliance forms, and the process for field verification and/or diagnostic testing. This section highlights compliance enforcement issues for water heating systems.
The design review verifies that the certificate of compliance matches the plans and specifications for the proposed building. The certificate of compliance has a section where special features are listed. The following are water heating features that should be listed in this section of the certificate of compliance:
1. Any system type other than one water heater per dwelling unit
2. Non-NAECA large water heater performance
3. Indirect water heater performance
4. Instantaneous gas water heater performance
5. Distribution system type and controls
6. Solar system
7. Combined hydronic system
If any of these measures are called out on the certificate of compliance, special attention should be given to make sure that identical information is located on the plan set. Highlighting key concerns or adding notes will allow field inspectors to quickly catch any measures that should be installed that made a significant difference in compliance.
During construction, the contractor and/or the specialty contractors complete the necessary sections of the certificate of installation. For water heating, there is only one section to be completed where information about the installed water heating system is entered if complying prescriptively with the installation of a gas instantaneous water heater. However, if complying prescriptively with a gas storage water heater, the completion of additional documents will be needed. (See Appendix A.)
Inspectors should check that the number and types of water heating systems indicated on the installation certificates match the approved certificate of compliance. The distribution system is also significant and must correspond to plan specifications.
5.11.3.1 Single Family
HERS verification is required for all hot water distribution types that include options for field verification. The first type is alternative designs to conventional distribution systems that include parallel piping, demand recirculation, and automatic and manual on-demand recirculation. The second type is for compact distribution systems, which can be used only when verified by field verification. In addition, HERS-verified QII is also required for users that comply prescriptively by installing a minimally compliant gas storage water heater that is 55 gallons or less; QII is not required if prescriptive compliance is pursued by installing a minimally compliant gas instantaneous water heater or gas storage water heater larger than 55 gallons. For all of the cases where HERS verification is required, the HERS Rater must verify that the eligibility requirements for the specific system are met.
In addition, HERS-verified pipe insulation is an option for prescriptive compliance and as a compliance credit for the performance approach. This credit applies if all pipes in a non-recirculating distribution system are insulated. HERS verification is required if this credit is taken in combination with the installation credit. Uninsulated hot water pipes in insulated walls or buried in the attic insulation would comply with the requirements. In this case a HERS Rater must verify that the eligibility requirements for pipe insulation have been met.
As previously described in this chapter, if a user wishes to comply prescriptively with the Energy Standards and installs a minimally compliant gas storage water heater (55 gallons or less) plus HERS-verified QII or a minimally compliant gas storage water heater with a storage volume greater than 55 gallons, then either the compact distribution design or insulation on all domestic hot water piping must be installed, both of which require HERS verification.
5.11.3.2 Multifamily
The only HERS verification for water heating that applies to central domestic hot water recirculation systems in multifamily buildings is the verification of multiple distribution lines for central recirculation systems.