Heat Recovery Ventilator Controller Variant 7 Kit with Arduino Uno + DHT22
Arduino-Based Heat Recovery Ventilator Controller Kit — Master Precision Climate Automation
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Build a fully functional heat recovery ventilator controller that actively decides when to run the fresh-air fan. Twin DS18B20 probes mounted inside and outside your space feed thermal data to an Arduino Uno, while a DHT22 tracks indoor humidity. The controller runs a differential algorithm that speeds up the DC fan only when bringing in outside air won't rob your room of expensive heated or cooled energy. This is climate-responsive automation for real Indian homes and campus hostels, where seasonal extremes demand intelligent air exchange decisions at every hour of the day.
What You'll Build
You assemble and program a vent control brain that reads indoor and outdoor temperature gradients through stainless-steel probes, compares moisture levels via a calibrated DHT22, and commands a 12V DC fan through an L298N driver. The 0.96-inch OLED displays real-time thermal deltas, fan PWM duty cycles, and time-stamped logs from the DS3231 RTC. When the microcontroller sees a favorable temperature difference, your system exchanges stale air without wasting air conditioning or heater output — a working controller you can deploy in a dorm room, apartment kitchen, or tinkering lab.
What You'll Learn
- Integrate multiple DS18B20 probes on a single OneWire bus and parse their unique ROM addresses in Arduino C++
- Calibrate and cross-reference DHT22 humidity readings to refine the ventilation trigger logic
- Program PWM-based fan speed curves on an L298N driver tied to real-time temperature differential thresholds
- Log sensor data with DS3231 RTC timestamps and render live dashboards on a 0.96-inch OLED display
Kit Contents
| Component | Quantity |
|---|---|
| Arduino Uno R3 | 1 |
| DS18B20 Probe | 3 |
| DHT22 | 1 |
| L298N Driver | 1 |
| DC Fan 12V | 1 |
| DS3231 RTC | 1 |
| 0.96in OLED | 1 |
| 4.7kΩ Resistors | 5 |
| 100nF Caps | 10 |
| PCB Prototype Board | 2 |
| 12V Adapter | 1 |
| Soldering Iron | 1 |
| Solder Wire | 1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part | Pre-tested as a system |
| Build support | Forums and scattered tutorials | AI companion trained on this exact project |
| Time to first working build | Days of debugging | Hours, with step-by-step guidance |
| Shipping coordination | Multiple sellers, multiple delays | One shipment from Bengaluru in 3-5 days |
Who This Kit Is For
This advanced controller build is designed for B.Tech ECE and EEE students executing Smart India Hackathon prototypes on energy-efficient building systems, and for IIT, NIT, VIT, or BITS Pilani undergraduates who need a working HVAC automation model for capstone projects. It also serves ATL Tinkering Lab instructors running advanced climate-monitoring workshops where participants must interpret sensor datasheets, design feedback loops, and solder prototypes on PCB boards. If you have prior experience with Arduino IDE and basic sensor wiring, this kit pushes your skills into closed-loop environmental control.
Built and Backed by Compoden
Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.
What if I get stuck during the build?
Scan the QR code inside the box to start a session with the AI companion trained on this exact HRV controller build. If the AI doesn't resolve your issue, a Compoden engineer will reply within 24 hours on WhatsApp or email with targeted debugging steps.
Can this controller handle a real HRV unit beyond the included DC fan?
The L298N driver can switch up to 2A at 12V, sufficient for small-to-medium axial fans. For larger blower motors, the control logic remains identical — you would replace the driver stage with an appropriate relay or MOSFET module while reusing the same Arduino code structure you develop with this kit.
Do I need to write the differential control algorithm from scratch?
The AI companion provides a baseline Arduino sketch that reads DS18B20 dual-probe deltas and maps them to PWM fan curves. You modify threshold values, hysteresis windows, and humidity compensation parameters as part of the learning process — the skeleton code is ready, the climate logic is yours to tune.
What calibration steps are needed for accurate indoor-outdoor comparison?
You will use the DS3231 RTC to log synchronized readings from all three DS18B20 probes in a controlled environment, calculate offset values, and apply those corrections in the main loop. The DHT22 requires humidity offset calibration using the saturated salt method, which the AI companion guides step by step.
DS18B20 probes inside and outside control HRV fan speed to maintain ideal fresh air exchange without heat loss.
What's in this kit
Choose your assembly option:
- Soldering Kit — 25W soldering iron, 60/40 solder wire, flux, and small perfboard for permanent assembly.
- Breadboard Combo — 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.
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Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items