Section 120.6[h]|topic=(h) Mandatory Requirements for Controlled Environment Horticulture (CEH) Spaces. sets efficiency standards for controlled environment horticulture (CEH) spaces. These standards are divided into indoor facilities which do not use sunlight and greenhouse CEH facilities. For indoor facilities, requirements exist for lighting technology and dehumidification. For greenhouses, there are requirements for lighting and building envelope materials. These requirements impact all newly constructed CEH spaces. These requirements will help reduce the energy usage of horticulture facilities that are becoming increasingly popular business operations across the state. These requirements not dependent on the type of crop is being grown in the facility.
§120.6[h]|topic=(h) Mandatory Requirements for Controlled Environment Horticulture (CEH) Spaces.
There are two main mandatory requirements in this section:
a. Indoor horticultural growing facilities - §120.6[h]|topic=(h) Mandatory Requirements for Controlled Environment Horticulture (CEH) Spaces.1 - 3, and
b. Greenhouse facilities - §120.6[h]4|topic=(h) Mandatory Requirements for Controlled Environment Horticulture (CEH) Spaces..
§120.6[h]1|topic=(h) Mandatory Requirements for Controlled Environment Horticulture (CEH) Spaces.
Section 120.6[h]1|topic=(h) Mandatory Requirements for Controlled Environment Horticulture (CEH) Spaces. sets efficiency standards for dehumidification equipment for indoor facilities. Compliance can be reached with one of the four following pathways.
•Dehumidifiers subject to federal appliance standards that comply with the federal performance and testing requirements; or
•Integrated HVAC system with on-site heat recovery designed to fulfill at least 75 percent of the annual energy for dehumidification reheat; or
•Chilled water system with on-site heat recovery designed to fulfill at least 75 percent of the annual energy for dehumidification reheat; or
•Solid or liquid desiccant dehumidification system for system designs that require dewpoint of 50°F or less.
Example 10-76
Question
How do I find a dehumidifier that meets the federal regulations?
Answer
The Department of Energy’s Compliance Certification Management System maintains a database of products that have been certified to meet the federal requirements.
Section 120.6(h)2 requires indoor CEH growing spaces with more than 40 kilowatts (kW) of horticultural lighting load to have electric lighting systems used for plant growth and maintenance that meet all of the below requirements:
1. Luminaires with removable lamps shall contain lamps with a rated photosynthetic photon efficacy (PPE) of at least 1.9 micromoles per joule (μm/J). All other luminaires shall have a rated PPE of at least 1.9 μm/J for the wavelengths between 400 and 700 nm. Photosynthetic photon efficacy is photosynthetic photon flux for the wavelengths between 400 nm and 700 nm divided by input electric power in units of micromoles per second per watt, or micromoles per joule as defined by ANSI/ASABE S640.
Note that some manufactures will also publish the total photon flux which includes the wavelengths outside of the 400 to 700 nm range. This higher photon flux value should not be used to calculate PPE as it includes wavelengths that are not photosynthetically active as defined by ANSI/ASABE S640.
2. Time-switch lighting controls shall be installed and comply with Section 110.9(b), the lighting control acceptance requirements of Section 130.4(a)4|topic=SECTION 130.4 –LIGHTING CONTROL ACCEPTANCE AND INSTALLATION CERTIFICATE REQUIREMENTS., and applicable sections of NA7.6.2|topic=NA7.6.2 Shut-off Controls Acceptance Tests.
3. Multilevel lighting controls shall be installed and comply with Section 130.1(b)|topic=(b) Multilevel Lighting Controls..
Electrical power distribution systems servicing indoor CEH spaces must be designed so that a measurement device is capable of monitoring the electric energy usage of aggregate horticultural lighting load.
A 40 kW threshold equates to roughly 800-1,000 square feet of canopy for an indoor grower using 1,000 watt high pressure sodium lights every 20-25 square feet. For compliance with existing California Department of Food & Agriculture CalCannabis regulations, growers must submit canopy size calculations and a lighting diagram for indoor and mixed-light licensing types. The lighting diagram includes the maximum wattage for each light so through this diagram one can determine total horticulture lighting load.
Luminaires with a PPE of 1.9 micromoles per joule will largely be LED with a tuned spectrum for growing plants or double-ended high-pressure sodium (HPS) lamps . LEDs are becoming more popular in the market as growers become familiar with their impacts on plant quality and yield. A photosynthetic photon efficacy (PPE) of 1.9 micromoles per joule for lamps can be met by high efficiency double-ended high-pressure sodium (HPS) lamps. HPS technology has been in the horticulture market for considerable time and use of highly efficient options will allow growers to use familiar technology while still achieving energy savings.
Example 10-77
Question
How do I find the photosynthetic photon efficacy of a particular lighting fixture or lamp?
Answer
A variety of options exist to determine the PPE of a given product. The DesignLights Consortium (DLC) Qualified Products List notes the PPE level of over 415 products from popular lighting manufacturers. If your product is not found in this listing, your manufacturer’s product specification may list PPE. Additionally, there are industry test procedures that can assist in the determination of a PPE level. IES LM-46-04: IESNA Approved Method for Photometric Testing of Indoor Luminaires Using High Intensity Discharge or Incandescent Filament Lamps is the most appropriate test standard for lamps and can be used to report PPE when certain data gaps are filled. The information needed to conduct the test procedure for PPE is found in existing IES standards, LM-51 and LM-79.
Section 120.6(h)4 provides separate building envelope requirements for conditioned greenhouses. Roof/ceiling and wall insulation must meet assembly requirements of Section 120.7. Buildings have different U-factor requirements for roof/ceiling and wall insulation depending on whether they are constructed with metal or wood products and their climate zones.
Non-opaque wall and non-opaque roof assemblies shall have greenhouse glazing with two or more glazing layers separated by air or gas fill.
Examples of non-opaque glazing products that meet these requirements include double pane glass, double and triple wall polycarbonate, and double film polyethylene.
Section 120.6(h)5 requires that space-conditioning systems used in conditioned greenhouses for plant production must meet requirements applicable to the systems
Pertaining to Section 120.6(h)6, greenhouse growing spaces with more than 40 kW of horticultural lighting load shall have electric lighting systems used for plant growth and maintenance that meet all of the below requirements:
1. Luminaires with removable lamps shall contain lamps with a lamp photosynthetic photon efficacy (PPE) of at least 1.7 micromoles per joule (μm/J); all other luminaires shall have a luminaire photosynthetic photon efficacy of at least 1.7 μm/J.
2. Time-switch lighting controls shall be installed and comply with Section 110.9(b), Section 130.4(a)4|topic=SECTION 130.4 –LIGHTING CONTROL ACCEPTANCE AND INSTALLATION CERTIFICATE REQUIREMENTS., and applicable sections of NA 7.6.2.
3. Multilevel lighting controls shall be installed and comply with Section 130.1(b)|topic=(b) Multilevel Lighting Controls..
A lamp and luminaire PPE of 1.7 μm/J can be met by high efficiency double-ended high-pressure sodium (HPS) and ceramic metal halide (CMH) lamps. HPS and CMH technology have been in the horticulture market for considerable time and use of highly efficient options will allow growers to use familiar technology while still achieving energy savings. LED technology is also an option for attaining a luminaire PPE of 1.7 μm/J.
Example 10-78
Question
How do these Title 24, Part 6 requirements interact with any CalCannabis requirements?
Answer
Title 24, Part 6 requirements for CEH greenhouses and indoor growing spaces apply to all building spaces that “are dedicated to plant production by manipulating indoor environmental conditions, such as through electric lighting, mechanical heating, mechanical cooling, or dehumidification.” The Title 24, part 6 requirements apply regardless of the type of crop grown in these spaces. Title 24, part 6 defines a CEH indoor growing space as having a skylight area to roof area ratio less than 50 percent. A CEH greenhouse has a skylight area to roof area ratio of 50 percent or greater. Thus, the Title 24 definitions of greenhouse and indoor growing space are solely determined by the fraction of roof area that has glazing and is not affected by how much electric lighting is used in the space.
CalCannabis (operated by the Department of Cannabis Control) grants licenses for cannabis growing. Different types of licenses are based on factors such as lighting density and light deprivation. As of 2021, CalCannabis defines Indoor Cultivation as “Cultivation of cannabis within a permanent structure using artificial light exclusively, or within any type of structure using artificial light at a rate above 25 watts per square foot.” Therefore, a CalCannabis indoor cultivation license applies to indoor spaces with no skylights and any space, even greenhouses, with more than 25 Watts of electric lighting per square foot of growing area. A CalCannabis mixed light cultivation license makes use of some amount of sunlight and must have no more than 25 Watts of electric lighting power installed per square foot of growing area.
The CalCannabis definitions of “indoor growing” and “mixed light” for licensure are not equivalent to the “indoor growing” and “conditioned greenhouse” definitions used for obtaining building permits under Title 24, Part 6 and are not relevant to Title 24 compliance.
There are no prescriptive measures for controlled environmental horticulture.
Section 120.6(h) applies to major retrofits of all CEH spaces. Alterations to indoor or greenhouse horticulture lighting systems that increase lighting wattage or that include adding, replacing, or altering 10 percent of more of the horticulture luminaires servicing an enclosed space must meet the applicable requirements of Section 120.6(h).
Greenhouses being converted into conditioned greenhouses or additions to conditioned greenhouses meet requirements of 120.6(h)yu A conditioned greenhouse is an enclosed space that is provided with wood heating, mechanical heating that has a capacity exceeding 10 Btu/hr-ft2 or mechanical cooling with capacity exceeding 5 Btu/hr-ft2. In conditioned greenhouses, space-conditioning systems used for plant production shall comply with all applicable Title 24, Part 6 requirements.
Example 10-79
Question
Alterations that change the occupancy group of a building do trigger the CEH requirements. Occupancy groups are defined in Chapter 3 of Title 24, Part 2. One common change of building type that would trigger the requirements is converting an indoor warehouse into a CEH grow facility of over 10 percent of the luminaires in my greenhouse or indoor CEH facility. Do I need to meet the lighting efficiency standards in 120.6(h)2 or 6?
Answer
Lamp replacements do not trigger the horticulture lighting efficacy alteration requirements. Only replacement of 10 percent or more of the horticulture luminaires serving an enclosed space trigger the lighting efficacy requirement. When replacing 10 percent or more of the luminaires in an enclosed space, only the replacement luminaires need to meet the applicable requirements.
Example 10-80
Question
If I replace the lamps of over 10 percent of the luminaires in my greenhouse or indoor CEH facility, do I need to meet the lighting efficiency standards in 120.6(h)2 or 6?
Answer
Lamp replacements do not trigger the horticulture lighting efficacy alteration requirements. Only replacement of 10 percent or more of the horticulture luminaires serving an enclosed space trigger the lighting efficacy requirement. When replacing 10 percent or more of the luminaires in an enclosed space, only the replacement luminaires need to meet the applicable requirements.