Heat Recovery Ventilator Controller Kit with Arduino Uno + DHT22
Build a Heat Recovery Ventilator with Arduino Uno & DHT22 – Fresh Air Without Heat Loss
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
This kit turns a handful of sensors and an Arduino Uno into a genuine heat recovery ventilator controller. Three DS18B20 probes monitor indoor, outdoor and fresh‑air channel temperatures, while a DHT22 tracks indoor humidity. The controller then continuously adjusts a 12V DC fan’s speed so the home gets clean air without dumping hard‑earned warmth on cold Delhi nights or losing coolness during a Chennai afternoon.
What You'll Build
You will assemble a standalone control unit with an OLED display that shows real‑time temperature differentials, fan duty cycle and the time from a DS3231 RTC. The enclosure‑ready board uses the L298N driver to vary fan voltage proportionally, and the RTC lets you schedule night‑purge or daytime economy modes. The result is a fully functional prototype you can mount inside an existing ventilation duct, complete with screw terminals and a power‑good indicator.
What You'll Learn
- Calibrating multiple DS18B20 probes on the same 1‑Wire bus and compensating for cable length differences
- Implementing closed‑loop fan speed control with a L298N H‑bridge and Arduino PWM
- Using a DS3231 real‑time clock to trigger scheduled ventilation profiles and time‑stamp sensor logs
- Building a menu‑driven OLED interface to set temperature thresholds and view system diagnostics
Kit Contents
| Component | Quantity |
|---|---|
| Arduino Uno R3 | x1 |
| DS18B20 Probe | x3 |
| DHT22 | x1 |
| L298N Driver | x1 |
| DC Fan 12V | x1 |
| DS3231 RTC | x1 |
| 0.96in OLED | x1 |
| 4.7kΩ Resistors | x5 |
| 100nF Caps | x10 |
| PCB Prototype Board | x2 |
| 12V Adapter | x1 |
| Soldering Iron | x1 |
| Solder Wire | x1 |
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 kit is built for final‑year B.Tech ECE/EEE students, Smart India Hackathon teams working on indoor air quality solutions, and makers from IITs, NITs, VIT or BITS Pilani who need a ready‑to‑assemble HVAC prototype. If you have already tinkered with Arduino sensors and want to dive into multi‑point temperature logging, real‑time scheduling and motor control in a single project, you will find it right here.
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?
Our AI companion walks you through every connection and code upload. For tricky hardware faults, WhatsApp support connects you directly to a build engineer.
Can I substitute the DC fan with a ceiling fan?
Yes, by swapping the L298N for a solid‑state relay and adjusting the control logic to phase‑angle firing. The AI companion includes a wiring diagram and sample code for that modification.
Does the kit handle 24/7 continuous operation?
Absolutely. The fan driver is rated for continuous duty, and the DS3231 RTC ensures reliable time‑based mode switching without drift. The 12V adapter has been tested for round‑the‑clock use.
How do I log sensor data to the cloud?
You can connect an ESP8266 module (not included) to the Arduino’s I2C pins. The companion guide provides circuit hints and code snippets to push readings to any MQTT broker.
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