{"product_id":"kit-heat-recovery-ventilator-controller-v7","title":"Heat Recovery Ventilator Controller Variant 7 Kit with Arduino Uno + DHT22","description":"\u003ch1\u003eArduino-Based Heat Recovery Ventilator Controller Kit — Master Precision Climate Automation\u003c\/h1\u003e\n\n\u003cp class=\"value-summary\"\u003eEvery part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.\u003c\/p\u003e\n\n\u003cdiv class=\"specs-strip\"\u003e\n  \u003cspan\u003e\u003cstrong\u003eDifficulty:\u003c\/strong\u003e Advanced\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eBuild Time:\u003c\/strong\u003e 6-8 hrs\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eAge:\u003c\/strong\u003e 18-21\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eSkill:\u003c\/strong\u003e Proportional-integral climate control programming\u003c\/span\u003e\n\u003c\/div\u003e\n\n\u003cp\u003eBuild 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.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Build\u003c\/h2\u003e\n\u003cp\u003eYou 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.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Learn\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eIntegrate multiple DS18B20 probes on a single OneWire bus and parse their unique ROM addresses in Arduino C++\u003c\/li\u003e\n  \u003cli\u003eCalibrate and cross-reference DHT22 humidity readings to refine the ventilation trigger logic\u003c\/li\u003e\n  \u003cli\u003eProgram PWM-based fan speed curves on an L298N driver tied to real-time temperature differential thresholds\u003c\/li\u003e\n  \u003cli\u003eLog sensor data with DS3231 RTC timestamps and render live dashboards on a 0.96-inch OLED display\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eKit Contents\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eComponent\u003c\/th\u003e\n\u003cth\u003eQuantity\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eArduino Uno R3\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDS18B20 Probe\u003c\/td\u003e\n\u003ctd\u003e3\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDHT22\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eL298N Driver\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDC Fan 12V\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDS3231 RTC\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e0.96in OLED\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e4.7kΩ Resistors\u003c\/td\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e100nF Caps\u003c\/td\u003e\n\u003ctd\u003e10\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePCB Prototype Board\u003c\/td\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e12V Adapter\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSoldering Iron\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSolder Wire\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhy Buy This Kit Instead of Sourcing Parts Separately\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFactor\u003c\/th\u003e\n\u003cth\u003eSourcing Separately\u003c\/th\u003e\n\u003cth\u003eCompoden Kit\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCompatibility checks\u003c\/td\u003e\n\u003ctd\u003eYou verify every part\u003c\/td\u003e\n\u003ctd\u003ePre-tested as a system\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eBuild support\u003c\/td\u003e\n\u003ctd\u003eForums and scattered tutorials\u003c\/td\u003e\n\u003ctd\u003eAI companion trained on this exact project\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTime to first working build\u003c\/td\u003e\n\u003ctd\u003eDays of debugging\u003c\/td\u003e\n\u003ctd\u003eHours, with step-by-step guidance\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eShipping coordination\u003c\/td\u003e\n\u003ctd\u003eMultiple sellers, multiple delays\u003c\/td\u003e\n\u003ctd\u003eOne shipment from Bengaluru in 3-5 days\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWho This Kit Is For\u003c\/h2\u003e\n\u003cp\u003eThis 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.\u003c\/p\u003e\n\n\u003ch2\u003eBuilt and Backed by Compoden\u003c\/h2\u003e\n\u003cp\u003eEvery 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.\u003c\/p\u003e\n\n\u003cdetails\u003e\u003csummary\u003eWhat if I get stuck during the build?\u003c\/summary\u003e\u003cp\u003eScan 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.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan this controller handle a real HRV unit beyond the included DC fan?\u003c\/summary\u003e\u003cp\u003eThe 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.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDo I need to write the differential control algorithm from scratch?\u003c\/summary\u003e\u003cp\u003eThe 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.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat calibration steps are needed for accurate indoor-outdoor comparison?\u003c\/summary\u003e\u003cp\u003eYou 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.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdiv class=\"kit-description\"\u003e\n  \u003cp\u003eDS18B20 probes inside and outside control HRV fan speed to maintain ideal fresh air exchange without heat loss.\u003c\/p\u003e\n  \u003ch4\u003eWhat's in this kit\u003c\/h4\u003e\n  \u003cul\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/uno-r3-ch340g-atmega328p-board-arduino-compatible\"\u003eArduino Uno R3\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/ds18b20-digital-temp-sensor-module-1-wire-55-to-125c\"\u003eDS18B20 Probe\u003c\/a\u003e x3\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/dht22-temperature-humidity-sensor-module-accurate-readings\"\u003eDHT22\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/l298n-motor-driver-module-specs-pinout-projects-compoden\"\u003eL298N Driver\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/l293d-motor-driver-shield-for-arduino-drive-dc-stepper-motors\"\u003eDC Fan 12V\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/ds3231-real-time-clock-module-i2c-rtc-with-battery-backup\"\u003eDS3231 RTC\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/096in-oled-display-128x64-i2cspi-for-arduino-raspberry-pi\"\u003e0.96in OLED\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/resistor-variety-pack-100-pcs-10-values-14w-carbon-film\"\u003e4.7kΩ Resistors\u003c\/a\u003e x5\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/capacitor-variety-pack-6-values-100nf-to-470uf-30-pieces\"\u003e100nF Caps\u003c\/a\u003e x10\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/esp-wroom-32-breakout-board-pcb-55x52mm\"\u003ePCB Prototype Board\u003c\/a\u003e x2\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/12v-2a-dc-adapter-reliable-power-supply-for-projects\"\u003e12V Adapter\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/soldering-kit-25w-with-solder-wire-flux-paste-compoden\"\u003eSoldering Iron\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/soldering-kit-25w-with-solder-wire-flux-paste-compoden\"\u003eSolder Wire\u003c\/a\u003e\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is included in the Heat Recovery Ventilator Controller Variant 7 Kit with Arduino Uno + DHT22?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The Heat Recovery Ventilator Controller Variant 7 Kit with Arduino Uno + DHT22 includes all components needed: Arduino Uno R3, DS18B20 Probe, DHT22, L298N Driver, DC Fan 12V and more. Everything is pre-tested for compatibility and shipped from Bengaluru, India.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What skill level is required for the Heat Recovery Ventilator Controller Variant 7 Kit with Arduino Uno + DHT22?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This kit is designed for Advanced level makers, suitable for ages 18-21. DS18B20 probes inside and outside control HRV fan speed to maintain ideal fresh air exchange without heat loss. Estimated build time is 6-8 hrs.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I buy the Heat Recovery Ventilator Controller Variant 7 Kit with Arduino Uno + DHT22 online in India?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, the Heat Recovery Ventilator Controller Variant 7 Kit with Arduino Uno + DHT22 is available online at Compoden (compoden.in), India's AI-powered electronics and robotics store. Ships from Bengaluru in 1-5 business days across India.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"Product\",\n  \"name\": \"Heat Recovery Ventilator Controller Variant 7 Kit with Arduino Uno + DHT22\",\n  \"description\": \"DS18B20 probes inside and outside control HRV fan speed to maintain ideal fresh air exchange without heat loss.\",\n  \"sku\": \"CDN-KIT-0291\",\n  \"brand\": {\"@type\": \"Brand\", \"name\": \"Compoden\"},\n  \"offers\": {\n    \"@type\": \"Offer\",\n    \"url\": \"https:\/\/compoden.in\/products\/kit-heat-recovery-ventilator-controller-v7\",\n    \"priceCurrency\": \"INR\",\n    \"price\": \"4070\",\n    \"availability\": \"https:\/\/schema.org\/InStock\",\n    \"seller\": {\"@type\": \"Organization\", \"name\": \"Compoden\"}\n  },\n  \"category\": \"Home Automation\"\n}\n\u003c\/script\u003e\u003cp\u003e\u003cstrong\u003eChoose your assembly option:\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSoldering Kit\u003c\/strong\u003e — 25W soldering iron, 60\/40 solder wire, flux, and small perfboard for permanent assembly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBreadboard Combo\u003c\/strong\u003e — 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Compoden","offers":[{"title":"Clone \/ Soldering Kit","offer_id":53455416066413,"sku":"CDN-KIT-0291-CL-SLD","price":3420.0,"currency_code":"INR","in_stock":true},{"title":"Clone \/ Breadboard Combo","offer_id":53459778240877,"sku":"CDN-KIT-0291-CL-BB","price":2890.0,"currency_code":"INR","in_stock":true},{"title":"R3 Original \/ Soldering Kit","offer_id":53455416099181,"sku":"CDN-KIT-0291-R3-SLD","price":5860.0,"currency_code":"INR","in_stock":true},{"title":"R3 Original \/ Breadboard Combo","offer_id":53459778273645,"sku":"CDN-KIT-0291-R3-BB","price":5330.0,"currency_code":"INR","in_stock":true},{"title":"R4 WiFi \/ Soldering Kit","offer_id":53455416131949,"sku":"CDN-KIT-0291-R4-SLD","price":5180.0,"currency_code":"INR","in_stock":true},{"title":"R4 WiFi \/ Breadboard Combo","offer_id":53459778306413,"sku":"CDN-KIT-0291-R4-BB","price":4650.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/kit-heat-recovery-ventilator-controller-v7.png?v=1781944360","url":"https:\/\/compoden.com\/products\/kit-heat-recovery-ventilator-controller-v7","provider":"Compoden","version":"1.0","type":"link"}