The DHW load for the Design Model is a user-defined load. The DHW load can be coupled from the room or decoupled from the room. Details of this have been explained in Section 1, “Assigning DHW load” of the “Modeling Domestic Hot Water” FAQ.
Furthermore, if there are multiple DHW systems serving the same building, then users can zone the DHW loads and assign the DHW zones to their respective DHW systems. Details of this have been explained in Section 2, “DHW Zones” of the “Modeling Domestic Hot Water” FAQ.
Proposed Model
Similar to the standard model, the DHW load of the proposed model is based on the thermal template assigned to the space. As per section 5.4.10 (Water Heating Use) of the Title 24 ACM, the DHW load is predefined in Appendix 5.4A and cannot be edited by users. The unit for the DHW load is Gal/hr/person.
Furthermore, if there are multiple DHW systems serving the same building, then users can zone the space with the identical system to the same DHW zone and assign the DHW zones to their respective DHW systems. In other words, users can have multiple DHW zones in the proposed model and each DHW zone can be assigned to a separate heating source(s). Steps to create DHW zones and assign spaces to these DHW zones are explained in Section 2, “DHW Zones” of the “Modeling Domestic Hot Water” FAQ.
Standard Model
Similar to the Proposed model, the DHW load of the proposed model is based on the thermal template assigned to the space. As per section 5.4.10 (Water Heating Use) of the Title 24 ACM, the DHW load is predefined in Appendix 5.4A and cannot be edited by users. The unit for the DHW load is Gal/hr/person.
Based on Appendix 5.4A, some spaces may have an “Electric” heating source and others may have a “Gas” heating source. If the building has a mix of spaces with “Electric” and “Gas” heating sources IESVE will create two DHW Zone groups, “Electrical source DHW” and “Gas source DHW” and assign the spaces with “Electric” heating source to “Electrical source DHW” and the spaces with “Gas” heating source to “Gas source DHW.”
