Sentinel CHHC-4i Digital Intelligent Total Environmental Controller

Cooling , Heating, Humidity, CO2 digital intelligent environmental controller with removable remote probe, weather-resistant main controller, Rohs construction, plant friendly green LED's, Digital Display.
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Additional Information

Name Sentinel CHHC-4i Digital Intelligent Total Environmental Controller
Brand Sentinel
Alternate SKU/MPN 703211
UPC 6944845010135
Warranty 2 Year
Voltage 120v
Amps 15A
MSRP $689.95
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    A: The Sentinel CHHC-4i Digital Intelligent Total Environmental Controller is produced for US/Canada use. Using plug adapters for another country is at your own risk. Happy growing!
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    A: Here is a link to the instructions: Happy growing!
  • 0
    A: Due to the Sentinel CHHC-4i Digital Intelligent Total Environmental Controller being rated for 15 amps max there is not a safe way to operate your air handler with this product.
  • 0
    A: Possible that the sensor probe got wet or the cable is not fully connected and cannot communicate with the unit. Here is some additional info:
  • 0
    A: Comes with a 6 foot power cord.
  • 0
    A: For ease of mind the Sentinel CHHC-4i Digital Intelligent Total Environmental Controller should be mounted outside the grow room. It CAN be mounted inside the room but it could be adversely affected by excessive humidity or if it is accidentally exposed to dripping, splashing or spraying of liquids. Protect unit from vapors, foggers etc.. Also keep the unit away from heat generating sources. Happy growing!
  • 0
    A: No this would not be safe since the fan is operating on 220v

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The Sentinel CHHC-4i is the most advanced CO2 controller available on the market today. It incorporates the proprietary S.I.C.E. – Sentinel Intelligent CO2 Enrichment – communication and control components and programming that are unique to Sentinel. This patent pending system allows for communications between Sentinel S.I.C.E series products, providing a level of control never before seen in your greenhouse, garden or grow room.

The system works by a Sentinel S.I.C.E. series controller, such as the Sentinel CHHC-4i, measuring and monitoring your growing environment. As the atmospheric CO2 levels change, the controller will tell the Sentinel ICG series generator to increase output, decrease output, or go into idle mode...all computer controlled. In this way, a growing environment that has very low Co2 levels, such as the start of the day or after a ventilation cycle, can be rapidly brought back up to optimal growing conditions. As the optimal conditions are reached, the S.I.C.E. system can decrease Co2 output, making sure that the user defined optimal level is not overshot. As needed, the growing environment can be "topped off" with CO2 enrichment on a lower output setting, allowing for air conditioners and dehumidifiers to better deal with the heat and moisture loads associated with Co2 enrichment and maintaining more constant temperature and rH levels.

  • New quick-disconnect on remote combo sensor for temperature, humidity, CO2 and light level. The combination sensor can be placed 16 feet from unit.
  • There are 3 environmental conditions which must be controlled for productive indoor growing. The CHHC-4 makes it easy to accurately control your "atmosphere" inside the area.
    • Temperature: The CHHC-4 has 2 separate outputs to control cooling and heating.
    • Humidity: The CHHC-4 can either increase or decrease the amount of humidity inside the area.
    • CO2 PPM: The CHHC-4 controls carbon dioxide with Part-Per-Million accuracy

  • The user can set separate day and night settings for temperature and humidity. The CO2 is activiated only during the "day" and has several modes of operation.
  • Besides controlling your growing area, the on-board memory stores the highest and lowest measurements to verify proper conditions are maintained.
  • No complicated menus to negotiate... the simple pushbuttons and LED display makes it EASY! The CHHC-4 uses a simple "operator interface" to access the settings and to recall the minimum and maximum recorded readings for CO2 level, temperature and humidity.


  • Controlled with Part-Per-Million accuracy.
  • Bright GREEN LED display shows the Temperature, Humidity and CO2 levels
  • Fuzzy logic mode can be used with compressed CO2 for greater accuracy.
  • The CHHC-4 is an all-in-one environmental controller.
  • All functions can be controlled individually. You set both high and low temperatures for the Day and Night... the CHHC-4 figures out the rest.
  • It has multiple modes of operation.
  • Cooling devices such as ventilation fans or air-conditioners connect to the cooling device receptacle.
  • A separate humidifier or dehumidifier can have separate Day and Night settings and is connected to the humidity device receptacle.

How to use:

  • Connect your CO2 generator or compressed CO2 solenoid / regulator assembly to the CO2 receptacle

Power Input 100 to 265V~
Circuit Breaker Rating 15 amp @ 240V~
Receptacle Rating 15 amp @ 120V~
10 amp @ 240V~
Temperature +/- 1.5'F / 32 to 120'F
Humidity +/- 3%rH / 10 to 90%rH
CO2 PPM +/- 85PPM / 350 to 2500PPM/td>

Customer Reviews

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Great Controller Review by BAE
Overall Rating
I've been running my CHHC-4i for a little over a year. It provides very granular control of the three key grow environment areas including temp (cooling or heating), humidity (humidify or dehumidify) and CO2 (either tanks or generator) and logs Min-Max values for each. Hysteresis bands are adjustable. The features make for a very powerful and adaptable unit. The programming can take some time to set up and fine tune but the resulting increased crop quantity and quality are worth it. (Posted on 11/17/2018)
Update to previous review Review by Dk
Overall Rating
This controller started out working great. After only a few weeks to a month, it started saying “error:co2”. This would cause any devices that were on to turn off temporarily. Usually the controller will go back to normal function. BUT about once a week it will just turn itself off. This is an extremely huge hassle and defeats the purpose of using the controller in the first place. I then have to reset the time and all previous settings remain the same. Then just one night ago the controller must of went haywire again and drained my entire 5’ tank of co2!!!!!! Considering I paid $500 for this unit I expected much better performance. I’ve tried contacting sentinel via their website, email, and social media to no avail. Growers house informed me they would put me in contact with their sentinel rep to resolve the issues I’m having. (Posted on 4/19/2018)
Controller Review by Dk
Overall Rating
This controller works extremely well.It precisely measures and maintains CO2 levels. It makes for a hassle free garden as this controller keeps rh and temps in check. (Posted on 10/26/2017)
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