Below is a practical, Indonesia‑focused plan to design, build and operate a smart greenhouse — from goals and site selection to sensors, automation, and maintenance. I’ll keep it actionable so you can start a small pilot (100–200 m²) and scale up.

Summary (one‑line)

• Build a well‑ventilated polyhouse/shadehouse suited for Indonesia’s hot, humid, and monsoonal climate; automate climate, irrigation and fertigation with low‑power IoT (ESP32/LoRa + Raspberry Pi gateway + MQTT/Node‑RED) and use IPM for pest control. Key local partners: Kementerian Pertanian programs and Telkom/Indonesian IoT vendors for connectivity and scale-up. (climateknowledgeportal.worldbank.org)

1. Start with goals, crops and budget

• Decide target crop(s): leafy greens (lettuce, pakcoy), chilies, cucumbers, tomatoes, or highland crops (strawberries, tomatoes) in cooler sites. Each crop has different light/water/spacing needs. Use a small pilot (50–200 m²) first to validate settings and ROI. (lahanirigasi.pertanian.go.id)
• Budget tiers (rough): DIY small pilot 100 m² ≈ USD 3,000–8,000 (IDR ~45–120M); low‑end commercial 1,000 m² ≈ USD 30,000–120,000+ (IDR ~450M–1.8B). (These are indicative — get quotes from local fabricators.)

2. Site selection & layout (Indonesia specifics)

• Pick a site with good drainage and easy water/electric access, not in flood‑prone low spots. Consider elevation: highland sites (cooler nights) reduce cooling needs for some crops. Indonesia is tropical with high humidity and heavy seasonal rains—plan for roof drainage and wind protection. (climateknowledgeportal.worldbank.org)
• Orientation: orient long axis east–west to get more even light distribution, and allow prevailing winds for natural ventilation where possible.
• Leave service space for tanks, pumps, control cabinet, and a shaded workspace.

3. Greenhouse type & materials (what works in tropical Indonesia)

• Common and cost‑effective: polyhouse / tunnel covered with UV‑stabilized polyethylene film (polyfilm) or shade net (for nurseries/leafy greens). Advantages: low cost, easy to repair. Lifespan of simple PE film is shorter in intense UV (replace every 2–5 years). (jhuete.com)
• For longer‑term/commercial: twin‑wall polycarbonate panels or rigid claddings (better durability, insulation, heavy rain/hail resistance) — higher CAPEX but lower replacement and maintenance. (growspan.com)
• Structure: galvanized steel frames (corrosion resistant) sized to withstand local wind/rain loads. Add gutters and water harvesting for irrigation.

4. Tropical climate control strategy (low energy, practical)

• Avoid trying to “heat” — you’ll mainly need to manage high temperature and high humidity:
  • Passive ventilation: ridge vents + side roll‑up curtains sized for cross‑flow. Proper vent area is critical in humid tropics.
  • Active ventilation: exhaust fans and circulation fans to move air and reduce localized humidity/condensation.
  • Shading: external shade cloth (30–50% for vegetables) to reduce solar load in hot months.
  • Evaporative/misting only where water quality is good and drainage is managed — they increase humidity so use carefully.
  • Dehumidifiers are energy‑intensive; better to design for airflow and crop spacing to reduce disease risk.
• Use anti‑condensate film/coatings or diffuse coverings to reduce drip and light hot‑spots. (help.hortitechdirect.com)

5. Water, irrigation & fertigation

• Use drip irrigation + fertigation for most vegetables; it’s water efficient and easy to automate with solenoid valves and dosing pumps.
• Include a water filtration/sediment system and a storage tank sized for dry season needs. Harvest roof runoff during rains for storage.
• Use flow meters and pressure sensors if you want accurate water accounting and fault detection.

6. Sensors, controllers and an example automation stack

• Minimum sensor set:
  • Air temperature & relative humidity (SHT31/SHT85 or industrial equivalents)
  • PAR / light intensity sensor (for crop light monitoring)
  • Soil/medium moisture (capacitive probes) or substrate EC/pH probes for fertigation control
  • CO2 sensor for fruiting crops (optional)
  • Roof/ambient rain and wind sensors (for safety/vent control) — useful in Indonesia’s monsoon storms
• Actuators:
  • Relay modules for fans, pumps, heaters (if used)
  • Motor controllers for vent/curtain motors
  • Solenoid valves for irrigation/fertigation
• Recommended architecture:
  • Sensor nodes: ESP32 or low‑power MCU for Wi‑Fi or LoRa node for longer range. Use industrial sensors for reliability at scale.
  • Gateway: Raspberry Pi or dedicated LoRaWAN gateway; forward data to an MQTT broker.
  • Software layer: MQTT → Node‑RED for logic + dashboards → Database/visualization (ThingsBoard, Grafana, or cloud IoT platform). Use mobile alerts (Telegram/WhatsApp/email) for alarms.
• Connectivity options in Indonesia:
  • If close to Wi‑Fi/cellular coverage, ESP32 + local 4G/3G router works.
  • For larger farms or remote locations, LoRaWAN is widely used in Indonesian smart‑ag deployments (low power, long range). Telkom and other local providers offer IoT/LoRa services. (lora-alliance.org)
• Example logic: if air temp > X °C → open side curtains/turn on exhaust fans; if soil moisture < Y% → turn on drip zone A for Z minutes; if EC out of range → suspend fertigation + alert.

7. Power & backup

• Grid power + inverter/UPS for the control cabinet and gateway.
• Solar + battery is popular for remote greenhouses; size solar to run pumps/fans during peak hours if grid unreliable.
• Prioritize UPS for controllers and comms to avoid data loss.

8. Pest & disease management (IPM)

• Use insect‑proof screens on vents and antechambers for seedling handling.
• Keep good sanitation: remove infected plants, control weeds, disinfect tools.
• Monitor pests with yellow sticky traps and use biological controls (parasitoids, predatory insects) when possible.
• In humid tropics, fungal diseases are common — spacing, airflow and fungicide rotation (if needed) are key.

9. Build & commissioning steps (practical timeline)

• Week 0–2: finalise crop plan, site survey, permits check with local desa/kelurahan and Kementan extension (if required).
• Week 2–6: order structure, covering, fans, pumps, tanks and IoT gear.
• Week 6–10: construct frame, install covering, gutters, irrigation plumbing and electrical.
• Week 10–12: install sensors, controllers, gateways; configure MQTT/Node‑RED dashboards and alarms.
• Week 12+: run a 4–8 week pilot (tune thresholds, irrigation timings), then document SOPs and scale.

10. Operation & maintenance

• Daily: quick checks of fans, vents and water pressure; review dashboard alarms.
• Weekly: clean gutters, inspect film or panels, check sensor calibration.
• Quarterly: replace worn film sections, check batteries, review data trends to optimize fertigation.
• Keep spare parts on hand (pump, relay module, spare film, sensor probes).

11. Local regulations, grants & partners (Indonesia)

• Kementerian Pertanian runs hortikultura/greenhouse programs and training — check local extension office for subsidies, training or pilot schemes. Recent collaborations with the Netherlands promote greenhouse tech in Indonesia. (lahanirigasi.pertanian.go.id)
• For connectivity and large‑scale IoT rollout, Telkom Indonesia and local AgTech providers offer LoRaWAN and smart‑farm platforms. Use them for regional coverage and scale. (theleap.id)

12. Example inexpensive parts list for a small pilot (100–200 m²)

• Frame & PE film or 8 mm twin‑wall polycarbonate (depending on budget)
• 2–4 circulation fans + 1 exhaust fan
• Side roll‑up curtains with motor(s)
• Irrigation pump + drip lines + solenoid valves + dosing pump (for fertigation)
• Sensors: 2× temp/humidity, 1× PAR, 4× soil moisture probes, 1× EC/pH probe (if fertigation)
• Controller: Raspberry Pi (gateway) + 2–4 ESP32 sensor nodes or LoRa nodes + relay board
• Software: Node‑RED + MQTT broker (Mosquitto) + dashboard (ThingsBoard/Grafana)
• Misc: UPS, cables, water tank