The Titan Controls Atlas 9 is a digital CO2 controller with an adjustable CO2 set point and a 15-foot remote sensor that holds a room at your target CO2 concentration by switching a CO2 device on and off. It reads the air with its remote sensor, and when CO2 falls below your set point it energizes the outlet driving a CO2 generator or a regulator on a compressed/bottled CO2 tank; a built-in photocell means it automatically disables the CO2 output during nighttime conditions, so it will not dose in the dark. This page gives Titan’s published range, accuracy, sensor length, and relay rating; explains how CO2 enrichment actually works and why it only pays off with adequate light; and says plainly who it is not for — all cited. It is a controller only: the CO2 source, tank, and regulator or generator are separate. This listing is the model with the remote sensor.
What it is
The Atlas 9 is a digital CO2 controller with an adjustable CO2 set point and a 15-foot remote high-quality CO2 sensor. You mount the controller on the wall and place the sensor probe out in the grow area; the controller compares the sensor reading to your set point and drives a single 120 V outlet accordingly. Titan states the sensor is an infrared CO2 sensor (the manual’s sulfur-vaporizer warning refers to protecting “the infrared CO2 sensor”). It is a switching controller, not a CO2 source — you supply the generator or the tank, regulator, and solenoid it turns on.
Guaranteed analysis and specifications
| Product type | digital CO2 controller with adjustable set point and 15-foot remote sensor |
|---|---|
| CO2 range | 400–2000 ppm |
| CO2 accuracy | +/- 100 ppm |
| Remote sensor cord | 15 ft |
| Relay / load rating | 10 amps @ 120 V AC / 60 Hz |
| Night behavior | photocell detects day/night; output is automatically disabled during nighttime conditions |
| Control modes | PPM Up (CO2 generator or regulator/tank) and Fuzzy Logic (regulator/compressed CO2 only — not for generators) |
| Operating temperature | 50 F to 95 F |
| Maximum relative humidity | 95% |
| Dimensions / weight | 5″ x 2.75″ x 3″, 1.1 lbs |
| Use environment | indoor use only |
| Manufacturer part number | HGC702854 |
Why choose the Titan Atlas 9
- Real closed-loop control, not a timer. It reads actual CO2 with a 15-foot remote sensor and holds your set point to +/- 100 ppm across a 400–2000 ppm range, rather than dosing blind on a clock.
- It will not waste CO2 in the dark. The photocell detects day/night and automatically disables the CO2 output during nighttime conditions — which matters because, as the horticultural literature shows, CO2’s benefit to photosynthesis is greater at high light than at low light because of the multiplicative interaction of light (PPFD) and CO2 concentration, so enriching when the lights are off buys nothing.
- Works with either CO2 source. It supports a PPM Up mode for a CO2 generator or a regulator on a compressed CO2 tank, and a Fuzzy Logic mode for a regulator and compressed CO2, so it fits a burner setup or a bottle-and-solenoid setup.
- Sized for a small load. Its outlet is rated 10 amps at 120 V AC / 60 Hz, enough to switch a tank solenoid or a small generator — the maker directs that the total connected load must not exceed a total of 10 amps.
- Simple to program. A single knob-and-push interface sets the CO2 PPM set point, the dead-band, and a Min/Max CO2 recall of the lowest and highest ppm over a 24-hour period.
Best uses for the Atlas 9
- Sealed indoor rooms and tents under strong light. CO2 enrichment pays off only when light is not the limiting factor — raising CO2 helps more under high light than low light because light and CO2 interact multiplicatively — so this suits a sealed space with adequate lighting.
- Bottled/compressed CO2 with a solenoid regulator. Use Fuzzy Logic mode, which applies fuzzy-logic control to the output for a regulator and compressed CO2 and is not for use with CO2 generators.
- CO2 generators / burners. Use PPM Up mode, which drives a CO2 generator (or a regulator and tank).
- Targeting the CO2 enrichment band. Its 400–2000 ppm range spans the levels the literature associates with a large photosynthesis gain — net photosynthesis increased by about 51% when CO2 was raised from 400 to 1000 across all light treatments in a peer-reviewed tomato study.
- Indoor only. It is designed for indoor use only, within its 50–95 F operating range.
How CO2 enrichment works — and why light comes first
Ambient air sits at roughly 400 ppm CO2, the baseline used as the atmospheric reference in the horticultural literature. Enriching the air above that raises the rate of photosynthesis: a peer-reviewed tomato study found net photosynthesis rose about 51% when CO2 was increased from 400 to 1000 across all light treatments. But CO2 is not a substitute for light. The same work reports that the effect of high CO2 on net photosynthesis is greater at high than at low light because of the multiplicative interaction of light (PPFD) and CO2 concentration, and that a 10% reduction in light can be compensated by raising CO2 by about 100, and over-compensated by about 40% by holding CO2 at 1000 instead of 400. The practical reading: enrich only while the lights are on and adequate — which is exactly what the Atlas 9’s photocell does by disabling output at night.
How it compares to other CO2 approaches
This table is factual — it does not claim one approach out-performs another; which suits your room is a grower’s judgement.
| Factor | Titan Atlas 9 controller | A simple CO2 timer/flow method | A CO2 bag / passive source |
|---|---|---|---|
| Control | reads CO2 with a remote sensor and holds an adjustable set point | doses on a clock or fixed flow, without reading room CO2 | releases CO2 passively; no measurement |
| Accuracy | +/- 100 ppm | none stated — open-loop | none — uncontrolled |
| Night handling | photocell disables output at night | needs a separate timer to stop at night | continuous — no day/night logic |
| Source it drives | CO2 generator or regulator/tank | varies | self-contained |
Compatibility and operating range
Titan publishes the electrical and environmental limits below; anything it does not state is held rather than guessed.
- Power / load: 10 amps at 120 V AC / 60 Hz; the maker directs plugging it into a surge protector and verifying that connected equipment does not exceed a total of 10 amps and is the proper voltage.
- Environment: indoor use only, 50–95 F, up to 95% relative humidity; do not let it get wet or sprayed.
- Sulfur vaporizers: the maker warns that if a sulfur vaporizer is used you must first remove the remote sensor from the area or cover the probe with a protective bag, or the infrared CO2 sensor will be damaged and the warranty voided.
- Calibration: Titan directs calibrating the sensor outdoors, away from people/animals/cars, reading CAL/400, roughly every 3 years.
How to set it up
A simple order of operations, from the maker’s instructions:
- Mount the controller on the wall and plug it into a standard 120 V outlet (via a surge protector), then place the remote sensor out in the grow area.
- Set the CO2 PPM target — the factory setting is 1000 ppm, with a 100 ppm dead-band — within the 400–2000 ppm range.
- Choose the mode for your source: PPM Up for a generator (or regulator/tank), or Fuzzy Logic for a regulator and compressed CO2 (not generators).
- Connect your CO2 device to the controller’s outlet. The photocell automatically disables the output at night, so it enriches only during the light period.
Where it fits
For other options in this part of the catalogue, browse the temperature and humidity category. General store policies are described on the about page. As an environmental controller, what it does for your yield depends on your light, room sealing, and crop.
Frequently asked questions
What CO2 range and accuracy does it hold? 400–2000 ppm, to +/- 100 ppm.
Will it dose CO2 at night? No — its photocell detects day/night and automatically disables the output during nighttime conditions, which fits the horticulture: CO2’s photosynthesis benefit is greater under high light because light and CO2 interact multiplicatively.
Does it work with a bottle or a burner? Both — PPM Up mode drives a CO2 generator or a regulator/tank, and Fuzzy Logic mode is for a regulator and compressed CO2 (not generators).
How long is the sensor cord and how much load can it switch? A 15-foot remote sensor cord, switching up to 10 amps at 120 V AC / 60 Hz.
Does it come with the CO2 tank or generator? No — it is a controller; the CO2 source (generator, or tank plus regulator/solenoid) is separate.
Who this is for — and who should skip it
Suited: growers running a sealed or semi-sealed indoor room or tent with adequate light, who supply their own CO2 (a generator, or a tank with a regulator/solenoid drawing under 10 amps at 120 V) and want closed-loop control that stops dosing at night.
Not for / its limits: it is a controller only — it contains no CO2 and drives, but does not include, the generator, tank, regulator, or solenoid. It is indoor-use-only, caps at 10 amps at 120 V AC / 60 Hz (a larger burner or 240 V gear is out of scope), and enrichment is pointless where light, not CO2, is the limiting factor — CO2’s benefit is greater at high light because the two interact multiplicatively. Held rather than guessed: Titan does not publish a per-crop yield figure for this device, so we make no yield claim. CO2 is an asphyxiant at high concentration and enrichment happens in spaces people enter; we could not this session trace a specific human-occupied-space CO2 safety ppm limit to a Tier-1 source we actually read, so we do not state one — treat a CO2-enriched room as a space needing proper ventilation and monitoring, and consult a current safety authority for exposure limits. We also do not state a street price here (it lives in the store’s price field), and we describe the sensor only as the maker’s own “infrared CO2 sensor” wording — we do not assert a formal NDIR spec the maker does not print.
Ready to add CO2 control to your room? Add to cart, or talk to a grower about whether CO2 enrichment fits your light and setup.
Sources
- Titan Controls — Atlas 9 CO2 Controller with Remote Sensor, Instruction Manual (Revision G, 05/19/2017; Sunlight Supply Inc., Vancouver WA). Source of every device spec: CO2 range 400–2000 ppm, +/- 100 ppm accuracy, 15 ft sensor cord, 10 amp @ 120 V AC/60 Hz load, 50–95 F, 95% RH, dimensions/weight, indoor-only, PPM Up / Fuzzy Logic modes, photocell night-disable, factory 1000 ppm / 100 ppm dead-band, 3-year calibration, sulfur-vaporizer and total-load warnings, “infrared CO2 sensor” wording (retrieved 2026-07-06): https://sprouthousesupply.com/wp-content/uploads/2020/08/702854_Instructions.pdf
- Titan Controls — Atlas 9 product page (part number HGC702854; retrieved 2026-07-06): https://www.titancontrols.net/shop/product/titan-controls-atlas-9-co2-controller-with-remote-sensor
- Light-Mediated Reduction in Photosynthesis in Closed Greenhouses Can Be Compensated for by CO2 Enrichment in Tomato Production (peer-reviewed, 2021 — 51% photosynthesis rise from 400→1000; light × CO2 multiplicative interaction; 10% light offset by ~100 CO2; ambient 400 baseline; retrieved 2026-07-06): https://pmc.ncbi.nlm.nih.gov/articles/PMC8705473/
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