The cool corridor. Coolest zone by 5-9°F during peak heat. Home to the hydroponic system (60 positions), seedling shelves, and the patio door — the single most important climate variable in the building.
Climate Profile
Metric
Value
Context
Peak temperature (hot day)
~91°F
When south hits 100°F, east is at 91°F
Temperature delta vs avg
-5 to -9°F
Consistently the coolest active zone
Humidity
Higher than other zones
Hydro evaporation adds local RH
VPD
Lowest in greenhouse
Cool + humid = most plant-comfortable
Why It’s Coolest
Three factors stack to create the east zone’s microclimate:
Tree shade — A large tree on the east side blocks morning solar until ~10:18 AM. The shadow shifts west through the day, but the east wall gets the least total solar radiation. Light transmission at the east wall sensor position: 6.9% (vs 57% spec).
Patio door — The glass/screen combo at the NE corner provides cross-ventilation in summer. When open or screened, outdoor air enters here directly.
Blocked morning solar — The combination of tree shade and the house to the northwest means the east zone misses the strongest morning heating period.
Seasonal Door Management
Season
Patio Door Config
Effect
Winter
Glass insert in
Insulation. Minimal heat loss.
Spring/Fall
Glass insert, sometimes screen
Partial ventilation on warm days
Summer
Glass removed → screen or fully open
Major vent opening — cross-ventilation drops east zone temps significantly
The patio door is the #1 manual climate lever. Open it for cooling but lose humidity. Close it for fog retention but temps climb. On a 90°F/16% RH day, there is no configuration that achieves both comfortable temperature AND comfortable VPD simultaneously.
Physical Layout
Hydroponic System (~half of east wall)
Component
Spec
Rails
4” PVC, 3 rails (A, B, C)
Rows
2 per rail (top + bottom)
Positions
60 total (1-30 top row, 31-60 bottom row)
Media
Grodan rockwool → net cups → clay pellets
Nutrients
General Hydroponics Flora/Bloom/Grow
Type
Recirculating pump system
Grow lights
14× Barrina 2FT LED (7 per row, 12” OC, 336W total)
Hydro Water Quality Monitoring (YINMIK)
Parameter
Current Reading
Target
Status
pH
~1922 (raw)
5.5-6.5
⚠️ NEEDS CALIBRATION
EC
~1,400 µS/cm
800-2,500
✅ In range
TDS
~690 ppm
400-1,250
✅ In range
ORP
-1 mV
200-400 mV
⚠️ NEEDS CALIBRATION
Water temp
~70°F
65-75°F
✅ Good
Battery
1%
> 20%
⚠️ NEEDS ATTENTION
Wall Shelving (~half of east wall, south of patio door)
Position
Contents
Notes
EAST-SHELF-T1
Seedlings (unknown) on heat mat
Heat mat for germination
EAST-SHELF-T2, T3
Available
Grow lights: 5× Barrina 2FT
EAST-SHELF-B1, B2, B3
Available
Partially blocked by hydro tank below
Water Systems
System
Type
Control
Notes
Hydro recirculating
Continuous pump
Independent
Not on ESP32 control
Wall drip (shared)
pcf_out_1 pin 4
Scheduled 6 AM
Shared with south + west
South mister access
pcf_out_1 pin 3
VPD-triggered
South misters reach into east zone
Sensor Coverage
Sensor
Address/Source
Interval
Notes
Temperature
Modbus addr 5 (SHT3X)
10s
±0.3°C accuracy
RH
Same probe
10s
±2% RH
VPD
Derived on ESP32
10s
Magnus formula
pH
YINMIK (LocalTuya → HA)
5 min
Uncalibrated
EC
YINMIK
5 min
Flowing
TDS
YINMIK
5 min
Flowing
ORP
YINMIK
5 min
Uncalibrated
Water temp
YINMIK
5 min
Flowing
Soil moisture
Modbus addr 8 (DFRobot SEN0600)
30s
%VWC
Soil temp
Same probe
30s
°F
The east zone has the most comprehensive instrumentation of any zone — climate probe + 5 hydro parameters + soil probe.