## 5.9 Miscellaneous Energy Uses

Miscellaneous energy uses are defined as those that may be treated separately since they have little or no interaction with the conditioned thermal zones or the HVAC systems that serve them.

### 5.9.1 Water Heating

When the construction documents show a water heating system, the layout and configuration of the baseline building system shall be the same as the proposed design, e.g. the baseline building shall have the same number of water heaters and the same distribution system.

5.9.1.1 System Loads and Configuration

Water Heating System Name
Applicability | All water heating systems
Definition | A unique descriptor for each water heating system. A system consists of one or more water heaters, a distribution system, an estimate of hot water use, and a schedule for that use. Nonresidential buildings will typically have multiple systems, perhaps a separate electric water heater for each office break room, etc. Other building types such as hotels and hospitals may have a single system serving the entire building.
Units | Text, unique
Input Restrictions | Where applicable, this should match the tags that are used on the plans such that a plan reviewer can make a connection.
Standard Design | The naming convention for the baseline building system shall be similar to the proposed design.
Standard Design: Existing Buildings |

Water Heating Peak Use
Applicability | All water heating systems, required
Definition | An indication of the peak hot water usage (e.g., service to sinks, showers, kitchen appliances, etc.). When specified per occupant, this value is multiplied by design occupancy density values and modified by service water heating schedules to obtain hourly load values which are used in the simulation. Peak consumption is commonly specified as gallons per hour (gph) per occupant, dwelling unit, hotel room, patient room, or floor area. If consumption is specified in gph, then additional inputs would be needed such as supply temperature, cold water inlet temperature, etc. Software that specifies peak use as a thermal load in Btu/h can apply ACM rules for the mains (cold water inlet) temperature and supply temperature to convert the prescribed peak use from gph/person to Btu/h-person. The thermal load does not include conversion efficiencies of water heating equipment.
Units | gph/person
Input Restrictions | For nonresidential spaces, prescribed values from Appendix 5.4A if a service hot water heating system is installed; otherwise, all values are 0. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed.
Standard Design | Prescribed values from Appendix 5.4A if a service hot water heating system is installed; otherwise, all values are 0. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed.
Standard Design: Existing Buildings |

Water Heating Schedule
Applicability | All water heating systems
Definition | A fractional schedule reflecting the time pattern of water heating use. This input modifies the water heating peak use described above.
Units | Data structure - schedule, fractional
Input Restrictions | The schedules from Appendix 5.4A shall be used. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed.
Standard Design | The schedules from Appendix 5.4A shall be used. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed.
Standard Design: Existing Buildings |

Water Heating System Configuration
Applicability | All water heating systems
Definition | The configuration and layout of the water heating system including the number of water heaters; the size, location, length and insulation of distribution pipes; recirculation systems and pumps; and any other details about the system that would affect the energy model.
Units | Data structure
Input Restrictions | None
Standard Design | The baseline building shall have one gas storage water heater, except for high-rise residential buildings which shall follow the rules in the Residential ACM Reference Manual.
Standard Design: Existing Buildings |

Water Mains Temperature Schedule
Applicability | All water heating systems
Definition | A monthly temperature schedule indicating the water mains temperature. This temperature and the setpoint temperature are used to convert the load into a water flow rate.
Units | Data structure - schedule,°F
Input Restrictions | For nonresidential spaces, the schedules from Appendix 5.4A shall be used. The water mains temperature schedule shall be fixed for a given climate zone. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed.
Standard Design | For nonresidential spaces, the schedules from Appendix 5.4A shall be used. The water mains temperature schedule shall be fixed for a given climate zone. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual *are followed.
Standard Design: Existing Buildings |

5.9.1.2 Water Heaters

This section describes the building descriptors for water heaters. Typically, a building will have multiple water heating systems and each system can have multiple water heaters, so these building descriptors may need to be specified more than once.

Water Heater Name
Applicability | All water heaters
Definition | A unique descriptor for each water heater in the system. Some systems will have multiple pieces of equipment. For instance, a series of water heaters plumbed in parallel or a boiler with a separate storage tank.
Units | Text, unique
Input Restrictions | Where applicable, this should match the tags that are used on the plans such that a plan reviewer can make a connection.
Standard Design | The naming convention for the baseline building system shall be similar to the proposed design.
Standard Design: Existing Buildings |

Water Heater Type and Size
Applicability | All water heaters
Definition | This building descriptor includes information needed to determine the criteria from baseline standards. The choices and the associated rated capacity (heat input rate) are listed in the 2015 Appliance Efficiency Regulations, except that oil-fired water heaters and boilers are not supported.
Units | List conventional, heat pump split, or heat pump packaged
Input Restrictions | As designed
Standard Design | Gas storage water heater for nonresidential buildings and common, nonresidential spaces of high-rise residential buildings and hotel-motel guestrooms. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed.
Standard Design: Existing Buildings | Same as proposed if water heater is existing

Rated Capacity
Applicability | All water heaters
Definition | The heating capacity of a water heater (input rate) at the rated conditions specified in DOE 10 CFR Part 430 or ANSI Z21.10
Units | Thousands of British thermal units per hour (MBH)
Input Restrictions | As designed
Standard Design | The standard design capacity equals 60 percent of the total proposed design capacity (combined rated capacity, converted to gph, and storage capacity in gallons).
Standard Design: Existing Buildings |

Storage Volume
Applicability | Gas-fired water heaters
Definition | The storage volume of a gas-fired water heater used in the standby loss calculations and baseline calculations of energy factor
Units | Gallons
Input Restrictions | As designed
Standard Design | The compliance software shall size the storage tank to 40 percent of the proposed total rated capacity and storage volume for the peak hour, in gallons. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed.
Standard Design: Existing Buildings |

Input Power
Applicability | Heat pump water heaters
Definition | The total design electrical input to a heat pump water heater at design conditions. This power includes the input to the compressor, controls, evaporator fan, and pump (if present).
Units | Kilowatts (kW)
Input Restrictions | As designed
Standard Design | Not applicable
Standard Design: Existing Buildings |

Storage Tank Location
Applicability | Heat pump water heaters
Definition | The storage volume of a gas-fired water heater. This is used in the standby loss calculations and baseline calculations of energy factor.
Units | List: • Conditioned • Unconditioned
Input Restrictions | List see above
Standard Design |
Standard Design: Existing Buildings |

Energy Factor
Applicability | Equipment covered by the National Appliance Energy Conservation Act (NAECA), which includes small storage and instantaneous water heaters
Definition | The energy factor (EF) is the ratio of the energy delivered by the water heater divided by the energy used, in the same units. EF is calculated according to the DOE 10 CFR Part 430 test procedure, which specifies a 24-hour pattern of draws, a storage temperature, inlet water temperature, and other test conditions. These conditions result in the energy delivered for the test period. Energy inputs are measured for the same test period and the EF ratio is calculated.
Units | Unitless ratio
Input Restrictions | Building descriptors for the proposed design should be consistent with equipment specified on the construction documents or observed in the candidate building. For water heaters manufactured after June 1, 2017 that contain a Uniform Energy Factor, the EF shall not be input by the user, but shall be calculated by: Where:
| Energy Factor
| Recovery Efficiency
| Power Input (W)
| UEF
| Recovery efficiency defined as 0.80 for storage water heater UEF to EF conversion
Draw Pattern | a | b | c | d
Very Small | 0.250266 | 57.5 | 0.039864 | 67.5
Low | 0.065860 | 57.5 | 0.039864 | 67.5
Medium | 0.045503 | 57.5 | 0.039864 | 67.5
High | 0.029794 | 57.5 | 0.039864 | 67.5
Standard Design | For nonresidential buildings and nonresidential spaces, the EF for the baseline building system shall be determined from the Appliance Efficiency Regulations. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed.
Standard Design: Existing Buildings |

Uniform Energy Factor
Applicability | Equipment covered by NAECA that is rated after June 1, 2017 with a Uniform Energy Factor (UEF) that includes small storage and instantaneous water heaters
Definition | The UEF defines an efficiency level for a specific targeted use pattern
Units | Unitless ratio
Input Restrictions | Must meet mandatory minimum requirements defined by federal or state appliance efficiency standards
Standard Design | Not applicable
Standard Design: Existing Buildings |

First Hour Rating
Applicability | Water heating storage tanks with a UEF rating
Definition | The first hour rating is a measure of the overall capacity of the water heater that incorporates both the heat input rate and the tank storage capacity and is used to determine the draw pattern.
Units | gal/hr
Input Restrictions | As designed
Standard Design | Not applicable
Standard Design: Existing Buildings |

Draw Pattern
Applicability | Storage water heating tanks with a UEF rating
Definition | The draw pattern is determined as: very small, low, medium, or high from the user entry of first hour rating (FHR). Very small: 0-18 gal/hr Low: 18-51 gal/hr Medium: 51-75 gal/hr High: > 75 gal/hr
Units | List: • Very small • Low • Medium • High
Input Restrictions | Not user editable. Draw pattern is determined from FHR user input.
Standard Design | Not applicable
Standard Design: Existing Buildings |

Thermal Efficiency
Applicability | Oil and gas-fired water heaters not covered by NAECA
Definition | The full load efficiency of a water heater at rated conditions expressed as a dimensionless ratio of output over input. It is also referred to as recovery efficiency.
Units | Unitless ratio
Input Restrictions | Building descriptors for the proposed design should be consistent with equipment specified on the construction documents or observed in the candidate building.
Standard Design | For nonresidential buildings and nonresidential spaces, the thermal efficiency is determined from Table F-2 in the 2015 Appliance Efficiency Regulations. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed.
Standard Design: Existing Buildings |

Baseline efficiency is set from the Appliance Efficiency Regulations

Tank Standby Loss
Applicability | Water heaters not covered by NAECA
Definition | The tank standby loss for storage tanks, which includes the effect of recovery efficiency
Units | Btu/h for the entire tank
Input Restrictions | Standby loss is calculated as: Where:
| The standby loss fraction listed in the Energy Commission’s Appliance Database of Certified Water Heaters
| The actual storage capacity of the water heater as listed in the Energy Commission’s Appliance Database of Certified Water Heaters (gallons)
Standard Design | Table F-2 of the 2015 Appliance Efficiency Standards
Standard Design: Existing Buildings |

Tank Off-Cycle Loss Coefficient
Applicability | Water heaters
Definition | The tank standby loss coefficient (UA) for the water heater. For small water heaters covered by NAECA, the loss coefficient is a derived parameter, a function of the EF and recovery efficiency.
Units | Btu/h - °F
Input Restrictions | For NAECA covered water heaters, the loss coefficient is calculated by: Where:
| The energy factor of the rated water heater (unitless)
| The recovery efficiency of the rated water heater. If this data is not available the default shall be 0.78 for gas water heaters and 0.93 for electric water heaters.
| The input power to the water heater, in Btu/h
Standard Design | For nonresidential spaces, 10 Btu/h-F. For high-rise residential spaces and residential living spaces of hotels and motels (guestrooms), the rules in the Residential ACM Reference Manual are followed
Standard Design: Existing Buildings |

The baseline loss coefficient for NAECA water heaters shall be:

10 Btu/h-F for gas-fired water heaters

Off Cycle Parasitic Losses
Applicability | Water heaters
Definition | The rate of parasitic losses, such as a pilot light or controls, when the water heater is not heating
Units | Watts
Input Restrictions | As designed
Standard Design | 0
Standard Design: Existing Buildings |

Off Cycle Fuel Type
Applicability | Water heaters
Definition | The type of fuel that serves energy using parasitic equipment, such as a pilot light or controls, when the water heater is not heating
Units | List electricity, gas, oil, or propane
Input Restrictions | As designed
Standard Design | Not applicable
Standard Design: Existing Buildings |

Not applicable

On-Cycle Parasitic Losses
Applicability | Water heaters
Definition | The rate of parasitic losses, such as a pilot light or controls, when the water heater is not heating. It may be different than off-cycle losses if the flue energy is considered.
Units | Watts
Input Restrictions | As designed
Standard Design | Not applicable
Standard Design: Existing Buildings |

0

On-Cycle Fuel Type
Applicability | Water heaters
Definition | The type of fuel that serves energy using parasitic equipment, such as a pilot light or controls, when the water heater is not heating
Units | List electricity, gas, oil, or propane
Input Restrictions | As designed
Standard Design | Not applicable
Standard Design: Existing Buildings |

Water Heater Ambient Location
Applicability | Water heaters
Definition | The location of the water heater for determining losses and energy interaction with the surroundings
Units | List schedule, zone, outdoors
Input Restrictions | As designed
Standard Design | Not applicable
Standard Design: Existing Buildings |

Water Heater Compressor Location
Applicability | Heat pump water heaters
Definition | The location of the heat pump compressor for determining losses and energy interaction with the surroundings. The air temperature at the compressor location also controls the compressor’s crankcase heater operation.
Units | List zone, outdoors
Input Restrictions | As designed
Standard Design | Not applicable
Standard Design: Existing Buildings |

Zone

Tank Standby Loss Fraction
Applicability | Storage tank water heaters
Definition | The tank standby loss fraction for storage tanks
Units | Unitless
Input Restrictions | Prescribed to the value listed in the Appliance Database of Certified Water Heaters
Standard Design | Not applicable The part-load curve procedure in Title 24 can be an alternate method of specifying the effects of standby and parasitic losses on performance. The primary method is to specify a loss coefficient for the storage tank.
Standard Design: Existing Buildings |

Fuel Water Heater Part-Load Efficiency Curve
Applicability | Water heating equipment for which a loss coefficient is not specified (alternate method)
Definition | A set of factors that adjust the full-load thermal efficiency for part load conditions; set as a curve
Units | Percent (%)
Input Restrictions | The following prescribed curve shall be used based on user inputs. The curve shall take the form of a quadratic equation as follows: For Title 24, the coefficients shall be determined by: Recovery efficiency substituted with thermal efficiency when applicable. For boilers, instantaneous gas or other storage type water heaters, not in the scope of covered consumer products as defined in the Title 10 or the Code of Federal Regulations, Part 430: Required inputs and standard and proposed design assumptions depend on the type of water heater and whether or not it is a DOE covered consumer product. Where:
| The fuel heating part load efficiency curve
| The fuel consumption at part-load conditions (Btu/h)
| The fuel consumption at design conditions (Btu/h)
| The water heater capacity at part-load conditions (Btu/h)
| The water heater capacity at design conditions (Btu/h)
| Part-load ratio for the nth hour and shall always be less than 1
| The input capacity of the water heater expressed in Btu/hr
| Hourly standby loss expressed in Btu/hr. For large storage gas water heaters, STBY is listed in the Energy Commission’s appliance database. The value includes pilot energy and standby losses. For all systems, refer to equation N2-62.
| The standard recovery load, taken from Appendix 5.4A, in Btu/hr, adjusted for the number of occupants according to the occupancy schedules.
| The standby loss fraction listed in the Energy Commission’s Appliance Database of Certified Water Heaters
| The actual storage capacity of the water heater as listed in the Appliance Database of Certified Water Heaters
Standard Design | Not applicable
Standard Design: Existing Buildings |

5.9.1.3 Recirculation Systems

This section describes the building descriptors for hot water recirculation systems. The baseline building has a recirculation system when the proposed design does. This is one aspect of the water heating system configuration (see above).

Recirculating systems shall follow the rules set forth in Appendix E of the Residential ACM Manual.

5.9.1.4 Water Heating Auxiliaries

External Storage Tank Insulation
Applicability | All water heating systems that have an external storage tank
Definition | Some water heating systems have a storage tank that is separate from the water heater(s) that provides additional storage capacity. This building descriptor addresses the heat loss related to the external tank, which is an additional load that must be satisfied by the water heater(s).
Units | R-value (h-ft2-F/Btu)
Input Restrictions | As specified in manufacturer data and documented on the construction documents
Standard Design | Heat loss associated with the storage tank in the baseline building shall meet the requirements for an unfired storage tank in the baseline standards which is an insulation R-value of 12.5. The surface area and location of the storage tank shall be the same as the proposed design.
Standard Design: Existing Buildings |

External Storage Tank Area
Applicability | All water heating systems that have an external storage tank
Definition | Some water heating systems have a storage tank that is separate from the water heater(s) that provides additional storage capacity. This documents the entire exterior surface area of the tank.
Units | ft2
Input Restrictions | As specified in manufacturer specifications
Standard Design | Not applicable
Standard Design: Existing Buildings |

External Storage Tank Location
Applicability | All water heating systems that have an external storage tank
Definition | Location of the storage tank, used to determine the heat loss rate and energy exchange with the surroundings
Units | List schedule, zone, outdoors
Input Restrictions | As designed
Standard Design | Not applicable
Standard Design: Existing Buildings |

Heat Recovery
Applicability | Water heating systems that are coupled to heat recovery equipment
Definition | Building equipment such as air conditioners, chillers, and gas-fired generators that produce thermal energy that may be recovered and used to heat water. The heat-producing characteristics are generally defined for the equipment that is producing the heat, not the equipment that is receiving the heat (water heaters in this case). The building descriptors will vary depending on the equipment. The models for heat-producing equipment need to produce output on an hourly basis so that the schedule of heat production and heating needs can be aligned and evaluated in the water heating model.
Units | Data structure - depends on the equipment producing the heat
Input Restrictions | No restrictions, other than agreement with the construction documents
Standard Design | Not applicable
Standard Design: Existing Buildings |

Solar Thermal
Applicability | Water heating systems with a solar thermal system
Definition | A solar thermal water heating system consists of one or more collectors. Water is passed through these collectors and is heated under the right conditions. There are two general types of solar water heaters: integrated collector storage (ICS) systems and active systems. Active systems include pumps to circulate the water, storage tanks, piping, and controls. ICS systems generally have no pumps and piping is minimal. Solar systems may be tested and rated as a complete system or the collectors may be separately tested and rated. Solar Rating & Certification Corporation (SRCC) OG-300 is the test procedure for whole systems and SRCC OG-100 is the test procedure for collectors. The building descriptors used to define the solar thermal system may vary with each software application and with the details of system design. The solar fraction shall be estimated by the f-chart procedure for solar water heating systems.
Units | Unitless fraction
Input Restrictions | The solar fraction provided by the solar DHW system shall be between 0 and 1.
Standard Design | The baseline building has no solar auxiliary system.
Standard Design: Existing Buildings |

Combined Space Heating and Water Heating
Applicability | Projects that use a boiler to provide both space heat and water heating
Definition | A system that provides both space heating and water heating from the same equipment, generally the space heating boiler. Such systems are restricted by the baseline standards but may be modeled in the candidate building. The restrictions are due to the misalignment of the space heating load and the water heating load. The first is highly intermittent and weather dependent, and the latter is more constant and not generally weather-related.
Units | Data structure
Input Restrictions | The proposed design may have a combined space and water heating system.
Standard Design | The baseline building shall be modeled with separate space heating and water heating systems.
Standard Design: Existing Buildings |

### 5.9.2 Exterior Lighting

Outdoor lighting requirements are specified in Section 140.7 of the standards. Outdoor lighting shall not be modeled in the proposed design or standard design, and no tradeoffs are available with other building end uses or systems. Outdoor lighting shall meet all prescriptive requirements in the standards.

### 5.9.3 Swimming Pools

Swimming pools must meet applicable mandatory requirements and are not required to be modeled for Title 24 compliance or reach.

### 5.9.4 Other Electricity Use

This set of building descriptors should be used to include any miscellaneous electricity use that would add to the electric load of the building and would be on the building meter. These energy uses are assumed to be outside the building envelope and do not contribute heat gain to any thermal zone.

Miscellaneous Electric Power
Applicability | All buildings with miscellaneous electric equipment located on the building site
Definition | The power for miscellaneous equipment
Units | Watts (W)
Input Restrictions | As designed
Standard Design | Same as the proposed design
Standard Design: Existing Buildings |

Miscellaneous Electric Schedule
Applicability | All buildings with miscellaneous electric equipment located on the building site
Definition | The schedule of operation for miscellaneous electric equipment that is used to convert electric power to energy use
Units | Data structure - schedule, fractional
Input Restrictions | The schedule specified for the building should match the operation patterns of the system.
Standard Design | Same as the proposed design
Standard Design: Existing Buildings |

### 5.9.5 Other Gas Use

This set of building descriptors should be used to include any miscellaneous gas use that would add to the load of the building and would be on the building meter. These energy uses are assumed to be outside the building envelope and do not contribute heat gain to any thermal zone.

Other Gas Power
Applicability | All buildings that have commercial gas equipment
Definition | Gas power is the peak power which is modified by the schedule (see below).
Units | Btu/h-ft²
Input Restrictions | As designed
Standard Design | Same as the proposed design
Standard Design: Existing Buildings |

Other Gas Schedule
Applicability | All buildings that have commercial gas equipment
Definition | The schedule of operation for commercial gas equipment that is used to convert gas power to energy use
Units | Data structure - schedule, fractional
Input Restrictions | Continuous operation is prescribed
Standard Design | Same as the proposed design
Standard Design: Existing Buildings |