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VPD climate control
Temperature and humidity driven by VPD targets. 12 bands per growth phase × day/night. Hysteresis on every decision point eliminates oscillation.
Home Assistant VPD climate automation for grow tents
Your grow tent climate runs on autopilot. You stay in control.
SmartGrowLab Climate Brain is a ready-to-use Home Assistant YAML package that controls your fan, humidifier, optional heater and light schedule using VPD targets, day/night logic, and the sensors and smart plugs you already own.
One-time payment. Runs locally in Home Assistant. No subscription.
See how Climate Brain works
Plants from my own grow box, Home Assistant dashboard walkthrough and controlled automation demo using test sensors.
Subscribe to @SmartGrowLab ↗ — time-lapses, dashboard previews (Setup, Grow, Settings, Diagnostics), and setup walkthroughs.
A complete climate control layer for your Home Assistant grow tent
Climate Brain combines VPD targets, device timing, safety overrides, phase logic and diagnostics into one ready-to-install package.
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Climate Brain
Central decision engine running every 15 seconds. Priority cascade: safety → VPD → temperature. Min on/off times prevent device cycling.
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Emergency stop
One toggle stops all climate actuators. Heater, fan, humidifier — switched off. Light schedule remains independent.
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System health
Aggregate health indicator: OK, WARNING, ERROR, or OFF at a glance. Combines alarms, sensor status, mapping validation, and engine state.
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Automatic phases
Phase transitions happen automatically based on grow days. Photoperiod plants transition seedling → vegetative; autoflowers also vegetative → flowering. VPD and temperature targets adapt per phase, day and night.
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Air exchange calculator
Enter your box dimensions and fan airflow — Climate Brain calculates a recommended cyclic vent runtime to exchange the full air volume. Optional and available as a free tool.
Is Climate Brain right for your setup?
A quick fit check before you buy. Climate Brain is built for growers who already use Home Assistant and want local VPD control without writing everything from scratch.
Good fit
- ✓ You already use Home Assistant
- ✓ You run a grow tent or growbox
- ✓ You have temperature / humidity sensors in HA
- ✓ Your fan, humidifier and light are exposed as
switch.*entities - ✓ You want VPD-based control without writing everything from scratch
- ✓ You are comfortable copying files into your HA config and mapping entities
Not a fit
- — You do not use Home Assistant
- — You want a physical controller in the box
- — You expect plug-and-play hardware
- — You are not comfortable editing Home Assistant configuration files
- — You want cloud app control instead of local HA automation
Built by a Home Assistant grower, for Home Assistant growers
I’m Daniel – a Linux admin and home grower. SmartGrowLab started as my own Home Assistant setup for controlling climate inside my grow tent. The result is a documented, ready-to-use package for growers who want local VPD control without building everything from scratch.
Small, focused, and built for people who understand sensors, switches and local-first automation.
Install in 3 steps
Copy package files
Copy the SmartGrowLab package files into Home Assistant.
Add include lines
Add the package and dashboard include lines to configuration.yaml.
Configure from dashboard
Map your sensors and switches from the SmartGrowLab dashboard.
Uses your existing Home Assistant sensor.* and switch.* entities.
No custom integration. No proprietary controller. No subscription.
Founder Edition — limited launch window.
First public release of Climate Brain. Launch price is available until June 30. After the launch window, regular price is €59.
SmartGrowLab Climate Brain v1.0
€39 one-time · regular €59
The complete system. Full automation engine, dashboard, safety layers, installation guide and lifetime v1.x bugfixes, Home Assistant compatibility updates, and minor dashboard improvements. Launch price is available until June 30.
What you get after purchase- Complete Climate Brain v1.0 package for Home Assistant
- YAML files for mapping, climate logic and automations
- 4-view Lovelace dashboard: Setup, Grow, Settings, Diagnostics
- VPD-based climate control with phase targets and day/night logic
- Fan, humidifier, optional heater and independent light schedule
- Emergency stop, sensor failure handling and heater watchdog
- SmartGrowLab User Guide PDF (installation, mapping, troubleshooting)
- License for one Home Assistant instance
- v1.x bugfixes and Home Assistant compatibility updates
📦 Package contents (click to expand)
- mapping.yaml — helper entities for sensor and device mapping
- climate.yaml — VPD targets, sensor logic and day/night parameters
- automations.yaml — decision loop, safety logic and notifications
- ui-lovelace-smartgrowlab.yaml — dashboard with Setup, Grow, Settings and Diagnostics views
- SmartGrowLab_User_Guide.pdf — installation and configuration guide
- LICENSE.txt — license for one Home Assistant instance
Secure checkout via Gumroad · Launch price until June 30
Install as a Home Assistant Package — copy a folder, add a few lines to configuration.yaml, restart. Map your sensors and switches once, the rest runs automatically.
You could build it yourself. Here’s what we already solved for you.
You are not paying for a few YAML files. You are paying for a tested control system with VPD logic, dashboard, safety states and Home Assistant edge cases already handled.
DIY HA blueprints
Free
- Free
- Basic on/off only
- No VPD logic
- Limited safety
- No structured dashboard
- Self-assembly required
SmartGrowLab Climate Brain
€39 launch
- VPD control — 12 bands per phase
- 15s decision loop
- Dashboard in HA
- Open ecosystem (any sensor)
- 8 safety layers
- No subscription, ever
Dedicated controllers
€200–500
- VPD control
- Built-in display
- Closed ecosystem
- Proprietary sensors
- No HA integration
- Proprietary app ecosystem
Free tools and guides
Explore free resources to understand VPD, ventilation and hardware compatibility before you automate the tent.
What you need
FAQ
Is this a physical controller?
No. SmartGrowLab Climate Brain is a digital product — a Home Assistant Package (YAML configuration) that runs on your existing HA instance. You use your own sensors and smart plugs.
What does Founder Edition mean?
Founder Edition is the first public release of Climate Brain at launch pricing (€39). Launch price is available until June 30. After the launch window, the regular price is €59. Founders keep their license forever and receive v1.x bugfixes, Home Assistant compatibility updates, documentation updates, and minor dashboard improvements.
What's included in v1.x updates?
Bugfixes, Home Assistant compatibility patches, dashboard improvements, documentation updates, and minor setup enhancements. Larger feature modules (e.g. watering, light intensity, timelapse) may be released as separate add-on products.
Does Climate Brain handle ventilation timing?
Yes, if you choose to use cyclic ventilation. You can enter your grow box dimensions and fan airflow; the system calculates a recommended runtime to exchange the full air volume, with a phase multiplier. This is optional — Climate Brain works perfectly on VPD triggers alone if you don't need timed air cycles.
How does automatic phase change work?
You set the grow start date and pick the plant type. For photoperiod plants, Climate Brain only auto-transitions seedling → vegetative; you keep manual control over the switch to flowering (which is driven by your light schedule, not days). For autoflowers, Climate Brain handles both seedling → vegetative and vegetative → flowering automatically. You can turn auto phase change off entirely at any time.
What if a sensor fails?
If both temperature or both humidity sensors become unavailable, the sensor failure detection raises an alert, sends a notification, and Climate Brain falls back into safety ventilation mode — the fan keeps running to prevent heat or humidity buildup until at least one sensor recovers. Reminders fire every hour while the failure persists.
Does it need internet to run?
Climate Brain itself runs locally on Home Assistant. Cloud-based devices such as Tuya or Sonoff Cloud may work, but local-first devices such as Shelly, Tasmota, ESPHome or Zigbee are strongly recommended for unattended grows because they continue working without internet.
Can I use just one sensor?
Yes. Map your sensor to Sensor 1 and leave Sensor 2 empty. Climate Brain will use that single reading for all decisions.
Will my hardware work?
Yes, if Home Assistant exposes your climate readings as sensor.* entities and your controlled devices as switch.* entities. Climate Brain is brand-agnostic, but local and reliable devices are recommended for unattended grows. See the full mapping table in the Hardware Guide.
Can I install on an active grow?
Yes. The system can be installed in monitoring-only mode first, then activated. Full rollback at any point — it's a Package, not a custom integration.
What happens during a Home Assistant restart?
Home Assistant preserves the System Active state. If Climate Brain was running before the restart, it resumes immediately when HA comes back up — there is no global wait for sensors. All safety layers (heater watchdog, critical override, cyclic vent guardian, mapping validation) are active from the first decision cycle. If you prefer a cold start, toggle System Active off before the restart.
Is the heater required?
No. The heater is optional and the entire heating logic is gated on whether you map a heater switch. Climate Brain works without one — the dashboard shows "not configured" for the heater throughout the UI.
Is support included?
Yes — for verified Founder customers via email. Scope covers bugs in Climate Brain, mapping issues per documented procedure, and dashboard problems. General Home Assistant troubleshooting and custom integrations are out of scope.
What's NOT included?
Watering automation, PPFD/DLI light measurement, camera or live video, timelapse generation, HACS components, sensor drift detection, and runtime watchdogs for fan or humidifier. These are deliberately scoped out and may be released or added later.
Stop babysitting your grow tent climate.
Let Climate Brain handle VPD, temperature, humidity and safety — running locally on Home Assistant, every 15 seconds, without subscriptions.