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California Title 24

What it means. Why it matters.


California Title 24 updates

On January 1, 2023 updates pertaining to cannabis and other indoor agriculture went into effect for California’s Title 24, Part 6 (Energy Efficiency), which contains regulations relating to energy efficiency building regulations for all residential and non-residential buildings.

The updates include the new category Controlled Environment Horticulture (CEH) and subsections: Conditioned Greenhouses and Indoor Growing. Complete Title 24 updates can be found on California’s official government website.

New Definitions

New Definitions

Controlled Environmental horticulture (CEH)

Technical Definition: A Controlled Environment Horticulture (CEH) space is a building space dedicated to plant production by manipulating indoor environmental conditions, such as through electric lighting, irrigation, mechanical heating, mechanical cooling, or dehumidification. CEH space does not include building space where plants are grown solely to decorate that same space.

What this Means: CEH is broken down into 3 categories:

  • Greenhouses
  • Conditioned Greenhouses
  • Indoor Growing (Included in the CEH category separately because it uses much more energy than a greenhouse)

For CEH new construction, there are several new rules that need to be followed during the building process. You will want to be aware of these new rules to ensure your project doesn’t experience delays. It’s important to note: These regulations apply at the discretion of your building inspector and when they determine your building is approved for occupancy. In other words, if you have a multiple-phase buildout project, you may need to recheck your plans to ensure your dehumidification meets the minimum efficiency requirements (outlined in the charts below).

conditioned greenhouses

Technical Definition: A Conditioned Greenhouse is a greenhouse that is provided with wood heating, mechanical heating that has a capacity exceeding 10 Btu/hr-ft2, or mechanical cooling that has a capacity exceeding 5 Btu/hr-ft2.

What this Means: While this new section does not directly include dehumidification, we thought it would be worth including. Building out a conditioned greenhouse was previously regulated by generic regulations. The new definition and regulations were prompted by the large growth in the market, along with the high energy loads that come with greenhouses.

integrated hvac system

Technical Definition: An integrated HVAC system is an HVAC system designed to handle both sensible and latent heat removal. Integrated HVAC systems may include, but are not limited to: HVAC systems with a sensible heat ratio of 0.65 or less and the capability of providing cooling, dedicated outdoor air systems, single package air conditioners with at least one refrigerant circuit providing hot gas reheat, and dehumidifiers modified to allow external heat rejection.

What this Means: Integrated HVAC system is a newly defined system type which does not directly impact Quest equipment. It may, however, come into play if an integrated system is used in conjunction with Quest equipment. An example of this equipment type is Agronomic IQ.

Non-ducted requirements

Non-ducted Requirements

Example of Non-ducted Dehumidifier (portable as defined in Title 24).

Non-ducted (referred to as portable dehumidifier in Title 24): A dehumidifier designed to operate within the dehumidified space without the attachment of additional ducting, although means may be provided for optional duct attachment.

What this Means: If you are hanging your dehumidifier in a space with no ducting, these requirements will apply.

Title 24 Non-ducted (portable) Dehumidifier Minimum Requirements

10 CFR 430.32(v)2 Efficiency requirements for equipment at the following pint/day capacities Minimum integrated
energy factor (p/kWh)*
25.01-50.00**3.38 p/kWh
50.01 pints or more5.92 p/kWh
*Pints/kWh at rating conditions: 65 F | 60% RH
+*The Quest 70 qualifies under the 25.01-50.00 requirements at these conditions.

Qualifying Quest Equipment

Model Energy Factor @65 F | 60% RH
Quest 70**3.9 p/kWh
Quest 1006.4 p/kWh
Quest Dual 1058.5 p/kWh
Quest Dual 1556.6 p/kWh
Quest Dual 1657.0 p/kWh
Quest 225 (208/230V)6.6 p/kWh
Quest 335 (208V)7.2 p/kWh
Quest 335 (230V)6.7 p/kWh
Quest 335 (277V)6.9 p/kWh
Quest 506 (230V)6.5 p/kWh
Quest 506 (277V)6.5 p/kWh
Quest 746 (480V)6.3 p/kWh

Ducted requirements

DUCTED Requirements

Example of Ducted Dehumidifier (whole-home as defined in Title 24).

Ducted (referred to as whole-home dehumidifier in Title 24): A dehumidifier designed to be installed with ducting to deliver return process air to its inlet and to supply dehumidified process air from its outlet to one or more of the dehumidified space.

What this means: The use of any ducting qualifies a dehumidifier as a whole-home dehumidifier.

Title 24 Ducted (whole-home) Dehumidifier Minimum Requirements

10 CFR 430.32(v)2 Efficiency requirements based on case volume of equipment (cubic feet)Minimum integrated
energy factor (p/kWh)*
8 or less3.74 p/kWh
More than 85.09 p/kWh
*Pints/kWh at rating conditions: 73 F | 60% RH and 0.2″ external static pressure

Qualifying Quest Equipment

Model @73 F | 60% RH
Quest 704.2 p/kWh
Quest 100 6.9 p/kWh
Quest 110 (<8 ft3)5.2 p/kWh
Quest 150 (<8 ft3)4.4 p/kWh
Quest Dual 1059.0 p/kWh
Quest Dual 1557.3 p/kWh
Quest Dual 1658.0 p/kWh
Quest 225 (discontinued)5.5 p/kWh
QUEST 225 (208/230V)7.5 p/kWh
Quest 335 ( 208V)8.6 p/kWh
Quest 335 (230V)8.6 p/kWh
Quest 335 (277V)6.9 p/kWh
Quest 506 (230V)7.5 p/kWh
Quest 506 (277V)7.5 p/kWh
Quest 746 (480V)7.1 p/kWh
Quest 876 (230V)6.2 p/kWh