The thing nobody mentions

Why does a room full of capable people stop making good decisions after forty minutes?

It is not the meeting. It is not the coffee wearing off. It is a colourless, odourless gas that every person in that room is producing, continuously, with every breath they take — and that nobody in the building has ever thought to measure. It is carbon dioxide.

In a closed room of eight people it crosses 1,000 ppm within about twenty minutes, and by minute forty it is near 1,500 ppm. Nobody notices, because there is nothing to notice. And once you have seen what that does to a room, you cannot go back to not knowing.

You cannot see it. You cannot smell it. And it is already changing how you think.

2,368 ppm CO2 MINUTE 90 OF THE MEETING This is the yawn nobody blames on the room.

Eight people. One closed door. Ninety minutes.

A 6 × 5 metre meeting room. The air conditioning is on, so the windows are shut and the air is being recirculated. Nothing about this room is unusual. It is the room you were in on Tuesday.

Outside, the air sits at about 420 ppm. When the meeting starts, the room reads 550. Then everybody begins to breathe.

Scroll, and watch what the room does to itself. Nobody in it will notice a single thing. They will simply become worse at their jobs, politely, for an hour and a half.

This is not opinion. It is measurement.

21% Fall in cognitive-function score for every 400 ppm rise in indoor CO2. Measured on office workers doing office work. Allen et al., 2016 · Harvard T.H. Chan School of Public Health · Environmental Health Perspectives
2,500 ppm at which 6 of 9 measures of decision-making performance fell to levels the researchers classified as dysfunctional. Satish et al., 2012 · Lawrence Berkeley National Laboratory · Environmental Health Perspectives
1,000 ppm — the ceiling recommended for occupied indoor spaces. Your meeting room passes it before the first agenda item is finished. ASHRAE Standard 62.1 · WHO indoor air quality guidelines
A sealed window in a dark room, with green trees visible outside

The fresh air is right there. It is eight centimetres away.

Modern Indian buildings are sealed on purpose — for cooling, for quiet, for dust. Every one of those is a good reason. Together they removed the one thing the old ventilator did for free: they stopped the air from changing.

Here is the part that surprises people

Many readers have already spent money on this problem. They bought an air purifier. It is running in that room right now — and against carbon dioxide it does nothing at all.

A purifier pulls air in, filters the particles out of it, and pushes the same air back into the same sealed room. It is very good at dust and smoke. But CO2 is a gas, not a particle, and no HEPA filter removes it. The purifier cannot fix the problem, because the problem is not that your air is dirty. The problem is that your air is used.

And to be equally clear about what VentPlus is not

VentPlus is not an air purifier either, and it does not replace one. It removes nothing from your air. It has no filter.

It measures three things — carbon dioxide, temperature and humidity — and it switches your fan. It does not measure PM2.5, VOCs, formaldehyde, ammonia or carbon monoxide.

If your problem is smoke, dust or winter smog, you want a purifier. If your problem is a closed room full of people, you want ventilation. Most Indian homes and offices have both problems, and the two devices solve different halves of it.

What everyone bought

A machine that cleans the air already in the room, then hands it back to you to breathe a second time.

What the room actually needed

New air. Not filtered air. Not cooled air. Air from outside, brought in at the moment it is needed — and not one minute longer.

Why we build this

We believe no one should lose an hour of their own mind to a room they are sitting in.

Not a student in a classroom in Meerut. Not a surgeon on a third consecutive case. Not a child asleep behind a closed bedroom door for eight hours every night of their life. The air in a room is the one thing in it that nobody checks, and it is the one thing that everybody in it shares.

CO2 Levels in ppm —
Concentration vs. Cognitive Impact

CO2 is the primary indicator of whether a room is ventilated. As it rises, thinking measurably degrades: cognitive-function scores fall about 21% for every 400 ppm of increase, and by 2,500 ppm most measures of decision-making have dropped to levels researchers call dysfunctional. Allen et al., 2016, Harvard T.H. Chan School of Public Health · Satish et al., 2012, Lawrence Berkeley National Laboratory

CO2 Level (ppm) Air Quality Impact on Health and Performance
400 – 600 Excellent Fresh outdoor air. Optimal for productivity and deep sleep.
600 – 1,000 Good ASHRAE & WHO recommended range for indoor spaces.
1,000 – 1,500 Moderate Reduced alertness, slower decision-making begins.
1,500 – 2,500 Poor Yawning, drowsiness.
2,500 – 4,000 Very Poor Stuffy feeling, significant cognitive impairment. Avoid prolonged exposure.
Above 4,000 Severe Breathing discomfort, fatigue, headache, nausea. The room needs immediate ventilation.
Condensation on a closed bedroom window at dawn

This is what eight hours of your own breathing looks like.

A closed bedroom is the longest unventilated period in most people's day. By morning the air in it can pass 2,500 ppm — and you wake up dull, and blame the pillow, the phone, the late night. It was the room.

So we built the thing that watches it for you…

What we made

CO2 Monitor & Controller

for Offices, Class rooms, Gyms, Meeting halls Homes Greenhouses

It makes the invisible visible. Then it acts on it without being asked.

A precision NDIR sensor reads the air every few seconds and puts the number on a display, where a number that governs your day belongs. When CO2 climbs, VentPlus switches your fan on. When the air is fresh again, it switches the fan off. Outside air arrives at the moment it is needed and stops when it is not, so the room stays sharp and the electricity bill does not pay for it.

There is no app to remember to open. No setting to adjust. No guesswork. You set it once, and then you stop thinking about your air — which is the entire point. Designed and made in India.

ISO 9001:2015 Certified Manufacturer Designed & Made in India 1-Year Warranty
R
CO2 Monitor
700
ppm CO2
Temp
25
°C
Humidity
58
% RH
GOOD
RELAY 1
OFF
Wi-Fi Relay
OFF
VentPlus CO2-1000 · NDIR
Set levels on this unit Fan On: 1,000 ppm Fan Off: 800 ppm
Conference room where CO₂ can spike to 2,500 ppm within 90 minutes Conference room · CO2 rises silently during meetings

For workplaces

Offices

and Classrooms, Gyms, Meeting halls

For alert staff and enhanced productivity

In a typical meeting room with 8–12 occupants, CO2 starting at 600–800 ppm can skyrocket to 2,500 ppm within 60–90 minutes — the level at which most measures of decision-making have fallen to what researchers call dysfunctional (Satish et al., 2012). The VentPlus CO2 Monitor & Controller watches the air and drives your ventilation before anyone feels it. And when the office is sparsely occupied, it leaves the ventilation off and keeps the air-conditioning load low — fresh air is brought in only when it is actually needed. So the VentPlus CO2 Monitor & Controller doesn't just look after your team's health and alertness, it looks after your electricity bill too.

Details
Waking up fresh and stretching in the morning light — the result of good CO₂ control overnight Wake up alert, not groggy

For your family

Homes

Get up fresh in the morning

With the bedroom door closed for 8 hours at night, CO2 climbs from ~700 ppm at bedtime to over 1,600 ppm while you sleep. That groggy, heavy-headed feeling in the morning isn't just poor sleep, it's the air. Research links high overnight CO2 to restless, broken sleep and lower next-day alertness, and growing children — who breathe this same closed-room air all night — feel it most. The VentPlus CO2 Monitor & Controller watches the level through the night and runs your exhaust or fresh-air fan only when it is needed, so the air stays fresh without leaving a window open to dust, noise, insects or the cold. It works quietly in the background — no alarms, no fiddling — and switches the fan off once the air clears, so you wake up genuinely refreshed.

Details
VentPlus CO2 monitor and controller installation green houses for Healthy Indoor Air for better plant growth Greenhouse · CO2 enrichment under control

For growers

Greenhouses

Bumper harvest

Plants feed on CO2. Holding a greenhouse in the enrichment band of 400–2,500 ppm can lift yields by 20–30% — but only if the level is held steady. Too little and growth stalls; too much wastes costly gas and can stress the crop. In a sealed polyhouse the opposite problem also appears: a dense canopy in daylight can pull CO2 well below the outdoor level, quietly starving the plants of the very thing they grow on. The VentPlus CO2 Monitor & Controller watches the level continuously and acts on it — switching a CO2 generator, solenoid valve or vent fan through its built-in relay to dose when the air is low and ventilate when it climbs too high. It holds the level exactly where your crop wants it, at every growth stage, without constant manual checking. The same control works for mushroom farms, where each stage needs its own CO2 band — see our dedicated CO2 controller for mushroom farms, and the Wi-Fi data log lets you track and fine-tune it over time.

Details

Applications

Where VentPlus Is Used

Anywhere people gather or crops grow, carbon dioxide builds up and needs managing. The VentPlus CO2 Monitor & Controller is used across dozens of environments throughout India — the same plug-and-play unit, tuned to each space:

Offices, IT parks & co-working

Meeting rooms cross 2,500 ppm within 90 minutes — VentPlus keeps staff alert and productive.

Schools & classrooms

A full classroom can pass 2,500 ppm within an hour, dulling concentration. VentPlus keeps students sharp.

Gyms & fitness studios

An exercising person exhales up to 10× more CO2 — VentPlus ventilates exactly when it's needed.

Restaurants, bars & banquet halls

Crowded halls routinely cross 3,000 ppm; VentPlus drives fresh air in automatically.

Cinemas, auditoriums & seminar halls

Full houses build CO2 fast — VentPlus holds the air in the healthy range throughout.

Hospitals, clinics & waiting rooms

Waiting areas, OPDs, IVF labs and diagnostic centres benefit from steady, monitored air.

Homes, apartments & bedrooms

A closed bedroom climbs past 1,600 ppm overnight — VentPlus helps you wake up fresh.

Greenhouses & polyhouses

Hold the 400–2,500 ppm enrichment band for 20–30% higher yields, all day.

Mushroom farms

Holds the right CO2 band at each stage for better pins, fuller caps and even flushes.

Hydroponic grow rooms & grow tents

Enrich to 1,000–1,500 ppm to lift indoor grow-room yields by 30% or more.

Vertical & container farms

Precise CO2 control for stacked, sealed indoor growing environments.

Cold storage & warehouses

Monitor and ventilate confined storage, ripening chambers and food-processing units.

Basements & underground parking

Clear built-up CO2 from poorly ventilated lower floors and enclosed spaces.

Poultry & cattle sheds

Keep broiler sheds, hatcheries and animal housing within safe CO2 limits automatically.

Army bunkers & defence installations

Reliable CO2 control for enclosed barracks and underground command posts.

See all applications

Intelligent automation

Silent. Automatic. Effective

Typical VentPlus setup: exhaust / ventilation fan plugged into the AC socket on the VentPlus CO₂ monitor and controller
A typical VentPlus installation — exhaust fan driven by the CO2 monitor & controller.
1

Continuous CO2 monitoring

Industrial-grade NDIR CO2 sensor — the same technology used in professional air quality instruments — measures carbon dioxide, temperature, and humidity every few seconds. VentPlus acts as both a precision CO2 meter and an automatic CO2 detector that triggers action. All readings shown live on the large 128×64 LCD display.

2

Automatic activation

When CO2 crosses your set threshold — default 1,000 ppm — VentPlus switches on your fan via the built-in AC socket. An optional beeper alerts at 1,500 ppm.

3

Demand controlled ventilation

Once fresh air restores CO2 to your lower limit — default 800 ppm — the fan switches off automatically. This demand controlled ventilation approach saves energy and is compatible with existing HVAC systems. Energy saved, air quality maintained.

Note: In this setup, the exhaust fan is connected to the CO2 Controller output socket directly. In case the fan is far from the controller, we can use an optional Wi-Fi Relay unit (described later) to supply power to the fan. The relay in the Wi-Fi relay unit will turn on and off in unison with the CO2 Controller internal relay.

Wi-Fi Connectivity

VentPlus CO2 Monitor and Controller is a Wi-Fi enabled device. It connects to the internet through your Wi-Fi router at home or office. You only have to enter your Wi-Fi credentials once. After this it will connect to the internet automatically at power up. The real-time CO2 level, temperature, humidity and the relay status (On or Off) is uploaded every 30 seconds to the cloud. This data can be viewed from your mobile phone or a browser from any PC at monitor.ventplus.in.

In case a Wi-Fi router is not available, it can be disabled and the CO2 Monitor & Controller can work as a stand-alone device.

View current or historical CO2, fan ON/OFF, temperature and relative humidity graphs on an online dashboard Four graphs share one time window: CO2, fan ON/OFF with total fan-on time, temperature and relative humidity. The duration can be set from 1 hour to 24 hours and the end time chosen by the user. Live CO2, temperature, humidity, local relay status and Wi-Fi relay status (ON / OFF / Disconnected / Disabled) are shown at the top. If you observe that the fan runs for extended periods without CO2 level reducing to acceptable level, it signals insufficient ventilation capacity.
Excel Data Download Download the readings for the chosen time window as an MS Excel file: date and time, CO2 (ppm), temperature (°C), relative humidity (%), and local and Wi-Fi relay status for every reading — useful for compliance, audits, facility management or research.

Remote Wi-Fi Relay Unit

(Optional accessory)

While the main CO2 Monitor & Controller has a local relay with a 5 A 3-pin socket for connecting a fresh-air / exhaust fan, we also offer a remote Wi-Fi relay. This relay operates in unison with the local relay. It needs to be connected to the internet via a Wi-Fi router. It is useful if your fresh-air / exhaust fan needs power at a place other than where you intend to install the CO2 Monitor & Controller — you need not lay a power cable from the CO2 Controller to your fresh-air / exhaust fan. It is especially handy in modern homes where all the wiring is concealed and installing an exposed cable is not aesthetically acceptable.

This unit has a 3-position switch (Auto – Off – On). You can manually override the automatic control by the CO2 Controller.

Dimensions: 120 mm (W) × 80 mm (H) × 60 mm (D).

VentPlus remote Wi-Fi relay unit with 5 A 3-pin socket, Auto–Off–On switch, mains input cable and power plug

Real-Time and Historical CO2, Temperature
and Humidity Monitoring From Anywhere

Here is a screenshot of the online dashboard. If the CO2 Monitor & Controller was not installed, estimated CO2 levels are also plotted on the chart. As you can observe, the CO2 level would have risen from about 500 ppm at 21:10 when the bedroom doors closed to about 1800 ppm by 06:00 hr in the morning exposing you to the harmful CO2 levels for several hours. With CO2 Monitor & Controller installed, they never go above 1000 ppm and always maintain the indoor air quality 'Good'. Temperature and relative humidity have their own graphs on the same dashboard, over the same time window, and the Excel download includes CO2, temperature and humidity for every reading.

monitor.ventplus.in — VentPlus CO2 Monitor
VentPlus remote dashboard showing overnight bedroom CO₂ held low with the controller versus climbing to nearly 2000 ppm without it

VentPlus remote monitoring website — same interface works on mobile, tablet and desktop

Want to try it yourself? Open a live VentPlus dashboard right now — no login, no signup, straight into a real device's data: live readings, plus CO2, fan, temperature and humidity graphs you can download to Excel.

Open a Live Monitoring Dashboard →

Tap Open a Live Monitoring Dashboard and give it about 2 seconds to log in and load the live demo.

Product Models

Technical Specifications

Main Unit

Physical & Hardware
Dimensions130 mm (H) × 90 mm (W) × 65 mm (D)
Display128×64 pixel backlit graphic LCD
Keyboard4 keys: ESC, UP, DOWN, SEL
MicrocontrollerARM-based 32-bit
ConnectivityWi-Fi (data upload + relay pairing)
Input Power230V ±15%, 50 Hz AC
Fan SupplyAC socket on the left, max 3A / 700W
CO2 Generator SupplyAC socket on the right, max 3A / 700W (greenhouse configuration only)
Manual Override Switch3-position Auto / Off / On switch
Measurement & Operation
Sensor TypeNDIR (Non-Dispersive Infrared)
CO2 Measurement Range400 – 5,000 ppm (an extended-range 400 – 10,000 ppm model is under development — ask us)
CO2 Accuracy±(50 ppm + 5% of reading) after 10 min warm-up
Temperature0 – 50°C, ±1°C accuracy
Humidity0 – 95% RH, ±2% accuracy (10–90% RH)
Coverage AreaAbout 100 sq m (1,200 sq ft) if the air circulation in the room is moderate (so that the measured CO2 level is representative)
Operation24×7 continuous monitoring and control
Quality & Warranty
Warranty1 year manufacturer warranty
CertificationISO 9001:2015 certified manufacturer (Systellar Innovations)
OriginDesigned & Made in India

Wi-Fi Relay Unit (optional add-on)

Physical & Hardware
Dimensions120 mm (W) × 80 mm (H) × 60 mm (D)
Manual override switch3-position: AUTO / OFF / Manual ON
Input Power230V ±15%, 50 Hz AC
Fan SupplyAC socket, max 3A / 700W
Connectivity & Operation
CommunicationInternet-based (no shared Wi-Fi required)
PairingOne Main Unit pairs with one Wi-Fi Relay
Designed & Made in India by Systellar Innovations, a leading HVAC control manufacturer in India. VentPlus CO2 Monitor combines a precision carbon dioxide meter with an automatic CO2 controller and relay. Both models operate continuously at Indian mains voltage (230V AC, 50 Hz) and are rated for high-humidity environments up to 95% RH.

Downloads

Product brochure & user manual

Get the full VentPlus CO2 monitor & controller documentation — everything you need to evaluate, buy and install.

Product Brochure 2-page overview · PDF User Manual Setup & installation · PDF

Why VentPlus

VentPlus vs a typical CO2 monitor

Most CO2 meters only show you the number. VentPlus acts on it — and does the whole job, plug-and-play.

Capability VentPlus Typical CO2 monitor
Automatically controls your fan / ventilation✓✕ display only
Built-in AC fan socket + optional Wi-Fi relay✓✕
Wi-Fi remote monitoring + Excel data export✓✕ rare
Works for people and plants / mushrooms✓✕
Industrial-grade NDIR CO2 sensor✓Some
Demand-controlled ventilation (saves energy)✓✕
CO2 + temperature + humidity on one display✓Varies
Plug-and-play — no electrician needed✓N/A
Designed & made in India · warranty & local support✓✕ mostly imported

Buy online

Buy VentPlus

Order directly from our secure Shopify store. For bulk orders, multi-unit installations or a custom quote, get in touch — we serve clients across India.

VentPlus CO₂ Monitor & Controller Main Unit Essential

CO2 Monitor & Controller — Main Unit

The complete plug-and-play unit: NDIR CO2 sensor, LCD display, built-in relay with AC socket for your fan, and Wi-Fi remote monitoring. Everything you need to start controlling your air automatically.

Size: 130 mm (H) × 90 mm (W) × 65 mm (D)

₹8,499 — inclusive of GST & shipping across India

Buy Main Unit
VentPlus Wi-Fi Relay Unit with mains input cable Optional add-on

Wi-Fi Relay Unit

Controls a fresh-air / exhaust fan in a different room from the Main Unit — no power cable to run. Operates in unison with the Main Unit over the internet. Works only with a VentPlus Main Unit.

Size: 120 mm (W) × 80 mm (H) × 60 mm (D)

₹2,499 — inclusive of GST & shipping across India

Buy Wi-Fi Relay

Secure checkout via Shopify · Developed & made in India by Systellar Innovations

Common questions

Frequently Asked Questions

No. VentPlus is completely plug-and-play. Simply plug your exhaust or fresh-air fan into the AC socket on the left side of the unit, set your CO2 thresholds using the front-panel buttons, and it starts working immediately. No wiring or electrician required.
According to ASHRAE Standard 62.1 and WHO guidelines, CO2 should ideally stay between 600 and 1,000 ppm. Above 1,500 ppm indicates poor ventilation and causes fatigue, headaches, and reduced concentration. VentPlus maintains this range automatically.
Yes. Use the front-panel ESC, UP, DOWN, and SEL keys to set your own Fan ON level (default 1,000 ppm), Fan OFF level (default 800 ppm), and beeper alert level (default 1,500 ppm) to suit your specific space.
VentPlus uploads real-time data — CO2 level, temperature, humidity, local relay status, and Wi-Fi relay status — to a secure remote monitoring website via Wi-Fi. The website shows four graphs over any window from 1 to 24 hours, ending at a time you choose: CO2, fan ON/OFF with total fan-on time, temperature and relative humidity. One click downloads the readings to Excel: date and time, CO2 (ppm), temperature (°C), relative humidity (%) and relay status. It works in any browser on desktop or mobile — no app required.
VentPlus uses an industrial-grade NDIR (Non-Dispersive Infrared) CO2 sensor — the same technology used in professional air-quality instruments. It measures carbon dioxide directly and accurately (±(50 ppm + 5% of reading) after a 10-minute warm-up) and stays stable for years, without the drift of cheaper chemical sensors.
The Wi-Fi Relay is an optional add-on for controlling a ventilation fan in a different room from the Main Unit. It communicates with the Main Unit over the internet — they do not need to be on the same Wi-Fi network. If your sensor and fan are in the same room, the Main Unit's built-in AC socket is sufficient.
Each VentPlus unit joins your Wi-Fi just like a mobile phone does, so the number you can connect depends on how many devices your router allows at the same time, not on VentPlus. Remember that phones, laptops and TVs on the same router also count. The limit is usually printed on the router's box or manual; if not, your internet provider can tell you. On a farm with many crop rooms, make sure the Wi-Fi signal reaches every room. If one router is not enough, a bigger router or a second router solves it. Nothing on VentPlus needs to change.
Yes. VentPlus is widely used in mushroom farms to control CO2 at each growth stage and in greenhouses to hold the CO2 enrichment band (400–2,500 ppm, user-settable). The relay can also control a CO2 generator or solenoid valve via the AC socket.
A single VentPlus unit is suitable for areas up to 100 square metres. For larger spaces or multi-room installations, multiple units can be installed — each monitoring its own zone and controlling ventilation independently. The optional Wi-Fi Relay extends control to a second fan in a different room.
The VentPlus CO2 Monitor & Controller Main Unit costs ₹8,499 and the optional Wi-Fi Relay Unit ₹2,499 — both inclusive of 18% GST and courier charges anywhere in India. Order online, or contact Systellar Innovations at info@ventplus.in or +91 99170 80700 for bulk orders and volume pricing on multi-unit installations.

More from VentPlus

Other VentPlus HVAC Controllers

The following HVAC Controllers are coming soon:

We can also develop any HVAC controller that you always wanted but could not get it as it was too costly or not as per your requirements. We have Microcontroller hardware and software expertise and with AI assisted development, we can realize your dreams fast and within budget.

Get in touch

Ready for Healthier Air?

Looking to buy a carbon dioxide monitor or CO2 controller in India? Contact us for pricing, a custom quote, or technical details about your space. Our team is based in Meerut and serves clients across India.

Address

Systellar Innovations
Shankar Chowk, 302 Delhi Road
Meerut – 250002, Uttar Pradesh, India

Developed and manufactured in India

Send Us a Message

We typically respond within one business day.

Message Sent!

Thank you for reaching out. Our team will get back to you within one business day.