2019 Title 24 Part 6 New Design Requirements
Below are a few of the changes under the 2019 Title 24 Part 6 Energy Code. The information below will be needed to prepare a Title 24 Part 6 Energy Report. Most of the information pertains to "newly constructed, newly conditioned" residential spaces. However, there are a few notes that pertain to all new residential design drawings. Section II and Section III (Doors and Kitchen, respectively) pertain to all residential projects.
PHOTOVOLTAIC SYSTEMS:
A Photovoltaic System is required for every "newly constructed", "newly conditioned" residential space.
CalFlex Standard Design Parameters are: Roof Pitch is less than 7:12, PV unit installed between 150 degree to 270 degree azimuth.
If the design does not meet CalFlex Standard Design requirements above, here is the information needed to model the Photovoltaic System in the energy analysis.
- Output (as expressed in kW) [if unknown will use the standard PV size as shown in Table 7-1 below]
- Array Type (3 types available - choose one):
- Fixed (open rack) [this will be the default if an array is not specified]
- Tracking (one axis)
- Tracking (two axis)
- Tilt (as expressed in degrees)
- Azimuth (as expressed in degrees)
- Electronics (3 choices available) choose one:
- None [this will be the default if an electronic is not specified]
- Microinverters
- DC Power Optimizers
Prescriptive Requirements for Photovoltaic System
§150.1(c)14To comply with the prescriptive requirements, all low-rise single family and multifamily buildings are required to have a PV system installed unless the building qualifies for an exception. The minimum qualifying size of the PV system is based on the projected annual electrical usage as described by the Equation 7-1 below.
Equation 7-1
- kWPV required = (CFA x A)/1000 + (NDwell x B)
WHERE:
- kWPV = kWdc size of the PV system
- CFA = Conditioned floor area
- NDwell= Number of dwelling units
- A = Adjustment factor from Table 7-1
- B = Dwelling adjustment factor from Table 7-1
Exceptions to PV Requirements:
Annual Solar Access: The annual solar access is the ratio of solar insolation including shading over the solar insolation without shading. Refer to Example 7-12 for an example of how to calculate solar access.
Effective Annual Solar Access: The effective annual solar access shall be 70 percent or greater ofthe output of an unshaded PV array on an annual basis.
Effective Annual Solar Access Roof Areas: Roof areas that meet the Effective Annual Solar Access requirements and are at least 80 contiguous square feet.
There are six allowable exceptions to the prescriptive PV requirements as listed below.
Exception 1 may apply if there is limited unshaded roof space. No PV is required if the effective annual solar access is restricted to less than 80 contiguous square feet by shading from existing permanent natural or manmade barriers external to the dwelling, including but not limited to trees, hills, and adjacent structures.
Exception 2 may apply to climate zone 15, and the required PV size may be reduced, if there is inadequate space on the roof to accommodate the PV size specified in Section 7.2.1. The PV size shall be the smaller of a size that can be accommodated by the Effective Annual Solar Access Roof Areas, or a PV size required by the equation above, but no less than 1.5 Watt DC per square foot of conditioned floor area.
Exception 3 may apply to two storied residential buildings and the required PV size may be reduced if there is inadequate space on the roof to accommodate the PV size specified in Section 7.2.1. The PV size shall be the smaller of a size that can be accommodated by the Effective Annual Solar Access Roof Areas, or a PV size required by the Equation 150.1-C, but no less than 1.0 Watt DC per square foot of conditioned floor area.
Exception 4 may apply to three stories or higher residential buildings and the required PV size may be reduced if there is inadequate space on the roof to accommodate the PV size specified inSection 7.2.1. In all climate zones, for low-rise residential dwellings with three habitable storiesand single family dwellings with three or more habitable stories, the PV size shall be the smaller of a size that can be accommodated by the Effective Annual Solar Access Roof Areas, or a PV size required by the Equation 150.1-C, but no less than 0.8 Watt DC per square foot of conditioned floor area.
Exception 5 — for a dwelling unit plan that is approved by the planning department prior to January 1, 2020 with available solar ready zone between 80 and 200 square feet, the PV size is limited to the lesser of the size that can be accommodated by the effective annual solar access or a size that is required by the Equation 150.1-C.
Exception 6 may apply to buildings with a battery storage system. The required PV sizes from Equation 7-1 may be reduced by 25 percent if a battery storage system is installed. For single family building, the minimum capacity of the battery storage system must be at least 7.5 kWh. For multifamily buildings, the battery storage system must have a minimum total capacity equivalent to 7.5 kWh per dwelling. In all cases the battery storage needs to meet the qualification requirements specified in Joint Appendix JA12 and be listed with CEC.
If any of these exceptions apply to the new home project, please note the exception on the plans.
PHOTOVOLTAIC SYSTEMS STORAGE BATTERIES:
A credit is available for a Photovoltaic System Storage Battery. Please see attachment with this e-mail entitled: "JA12 — Qualification Requirements for Battery Storage System."
If a battery storage system is planned, please provide the following:
- Control Type (3 types available):
- Basic — Does not feed to the Grid
- Time of Use (Also provide discharge hour)
- Advanced DR (demand response) control
- Capacity (expressed at kWh)
- Efficiency of Charging (expressed as a percentage)
- Efficiency of Discharging (expressed as a percentage)
DOORS:
Doors are now looked at with more detail. On plans please notate:
- The complete size of the door in width and height.
- The type of door, such as solid core/opaque door, defined as, "An opaque door is an installed swinging door separating conditioned space from outside or adjacent unconditioned space with less than 25 percent glazed area."
Note: Opaque doors will have to meet an energy rating maximum of 0.20.
OR "glazed door", defined as an installed swinging door separating conditioned space from outside or adjacent unconditioned space with more than 25 percent glazed area. A glazed door is treated like a window/fenestration/glazing product.
KITCHEN FANS:
The proper installation of a new kitchenfan will now be verified by a 3rd Party HERS rater. The CFM must be in accordance with the listing on the CF-1R Title 24 Part 6 Energy Document.
On plans please notate in the kitchen area:
- The size of the designated kitchen area in width and length
- The ceiling height of the kitchen
Specify fans on plans listed in the Home Ventilating Institute directory, meeting CFM and Sone requirements shown on the CompuCalc provided Title 24 Part 6 Summary Sheet.
As always, I am available to discuss the process of meeting the California Energy Code for any building project. Contact me …