Controlled Environment Horticulture: Space Conditioning Systems for Indoor CEH

Measure Overview

This proposed measure would establish new mandatory sizing, functional, equipment, and controls requirements for space conditioning systems serving Indoor Growing spaces in Controlled Environment Horticulture (CEH) facilities. These systems provide cooling, heating, dehumidification, reheat, heat recovery, heat rejection, and airflow control to support plant growth.

The proposal applies to Indoor Growing spaces, a subtype of CEH space where actively growing plants are cultivated, not to greenhouse cultivation spaces or to non-cultivation spaces within a CEH facility. Other facility spaces, such as drying rooms, processing rooms, packaging rooms, offices, corridors, restrooms, break rooms, storage rooms, and support spaces, would continue to be subject to applicable nonresidential requirements based on occupancy and space type.

The new high-intensity Indoor Growing HVAC/D requirements would apply to facilities with at least 5,000 square feet of indoor plant canopy area served by horticultural lighting with power density greater than or equal to 30 watts per square foot of plant canopy area. The proposal would establish mandatory requirements only, clarify that Indoor Growing spaces are not subject to nonresidential prescriptive HVAC or envelope requirements, and would not allow performance-based HVAC/envelope tradeoffs for Indoor Growing. The proposal also establishes a California rating, test, and certification pathway for commercial dehumidifiers used in Indoor Growing spaces.

Table 1 summarizes the scope of the proposed code change. Note that this proposal includes acceptance testing performed by a field technician. Because the field technician is typically a member if the installation team, this acceptance testing is not considered “third party verification.”