SlideShare a Scribd company logo
1 of 10
1

    Darwish Al-Arafati 86949
     Nasr Al-Abdali 86996
•   Introduction
    •   Project Overall (Problem, Specifications and
        Constraints).
    •   Project Design and its principle.
    •   Sensor Specifications.
    •   Project and market Product Comparison.
    •   Conclusion
    •   References




2
Project Objective:
In the greenhouse the humidity level is very important as a very
humid atmosphere may be harmful to some plants because the rate of
transpiration and evaporation is reduced in a very humid conditions,
and these plants my suffer damage from overheating unless you use
the ventilation to bring into the greenhouse cooler and drier air. On
the other hand, many tropical plants from native humid climates
require high levels of humidity for a healthy growth and will not
survive in a dry atmosphere. That is why Controlling Humidity
needed!.

 Introduction:
 One of the biggest challenges in maintaining a greenhouse is
 humidity control. Most plants enjoy a humidity of 50 to 60
 percent, and this is a challenge to manage at times. The main
 goal is to avoid condensation on plants, which promotes mold
 and fungus growth. Low humidity leads to leaf dehydration,
 more frequent watering and pest infestation.


                                                                        3
1 Problem Statement                            2 Constraints
                                         Economical:[ Total Cost is equal
                                                    Nearly 8$]
Humidity level in Green                    Environmental: No Impact
                                          Health and Safety: It does not
Houses may affect plants
                                                   affect them.
       growth..                           Social and Cultural: System is
                                                   acceptable.
                                            Performance: Fast System
                                                    Response




                      3 Specifications


 •Performance: Accurate and It has Very Fast Response....
 •Functionality: System Will check Voltage across the Sensor ,so
 valid action will be done
 •Operational: System can work on the environment on which
 temperature lie between 10 to 60°C.
                                                                            4
How Does it work?!!


                                230 Vac




                      1k Ohms




                                          5
Project Cost



        Component Name                             Cost
        HS 1101 (HUMIDITY SENSOR)
                                                    4.6
      2 Comparators Operational Amplifier
                                                   1.36$
                   2 Relays
                                                   1.4$
                  4 Resistors
                                                   0.4$
                Total Cost                         7.76$

                                    1$≈0.385 O.R




                                                           6
Humidity Sensor Specifications




                                 7
Farm Greenhouse Humidity Controller Product
Compared With Project Design




    Comparison Side   Project/ Greenhouse   Farm Greenhouse Humidity
                      Humidity Controller   Controller

      Resolution             Lower                 Higher

   Measuring range       +0.1% RH/°C            +1% RH/°C
                          10 to 60°C           -40C~+85C

         Cost                   8$                    35$
                                                                       8
How to Improve Design?

•Using accurate components.

•Highly Sensitive Humidity sensor.

•Using Microcontroller instead of Comparators.

•Avoid using long wires and poor cables.




                                                 9
Conclusion:
       Humidity can be controlled easily using 2 comparators with few
       resistors and a sensor.45% of Humidity is perfect one for plants
       growth. By means of Humidity Absorption and Air Humidifier,
       Humidity is going to be controllable and being balanced to be
       45% in the air.




References
-http://www.ehow.com/how_2107526_manage-humidity-greenhouse.html
-http://fogco.com/applications/greenhouse
-http://www.ryanguitars.com/NewsandEvents/Guitar_tech_tips/Humidity_Chart.htm



                                                                                10

More Related Content

What's hot

P 6168--microcontroller based-lpg_gas_detector_using_gsm_module
P 6168--microcontroller based-lpg_gas_detector_using_gsm_moduleP 6168--microcontroller based-lpg_gas_detector_using_gsm_module
P 6168--microcontroller based-lpg_gas_detector_using_gsm_moduleChitrachedu Dada Kalandar
 
AUTONOMOUS LPG GAS SENSOR BOT USING ARDUINO ppt
AUTONOMOUS LPG GAS SENSOR BOT USING ARDUINO pptAUTONOMOUS LPG GAS SENSOR BOT USING ARDUINO ppt
AUTONOMOUS LPG GAS SENSOR BOT USING ARDUINO pptRavi Shankar
 
29. how does a thermal printer work.pdf
29. how does a thermal printer work.pdf29. how does a thermal printer work.pdf
29. how does a thermal printer work.pdfBarcode Live
 
LPG Gas detector
LPG Gas detectorLPG Gas detector
LPG Gas detectorajay singh
 
75600403 automatic-plant-irrigation-system
75600403 automatic-plant-irrigation-system75600403 automatic-plant-irrigation-system
75600403 automatic-plant-irrigation-systemstk25
 
Gas & smoke detector Report
Gas & smoke detector ReportGas & smoke detector Report
Gas & smoke detector ReportToushik Paul
 
Gas Leakage Detector using Arduino with SMS Alert - Engineering Project
Gas Leakage Detector using Arduino with SMS Alert - Engineering ProjectGas Leakage Detector using Arduino with SMS Alert - Engineering Project
Gas Leakage Detector using Arduino with SMS Alert - Engineering ProjectCircuitsToday
 
Temp based fan speed control
Temp based fan speed controlTemp based fan speed control
Temp based fan speed controlSai Malleswar
 
Microcontroller Based LPG Detector Using GSM Module
Microcontroller Based LPG Detector Using GSM ModuleMicrocontroller Based LPG Detector Using GSM Module
Microcontroller Based LPG Detector Using GSM ModuleManish Patel
 
Tracking system on IOT
Tracking system on IOTTracking system on IOT
Tracking system on IOTAlex Vishwa
 
DHT11 Digital Temperature and Humidity Sensor
DHT11 Digital Temperature and Humidity SensorDHT11 Digital Temperature and Humidity Sensor
DHT11 Digital Temperature and Humidity SensorRaghav Shetty
 
gsm based Voting system
gsm based Voting system gsm based Voting system
gsm based Voting system sebinkb
 
IRJET- Forest Fire Detection and Alerting System
IRJET- Forest Fire Detection and Alerting SystemIRJET- Forest Fire Detection and Alerting System
IRJET- Forest Fire Detection and Alerting SystemIRJET Journal
 
Application of Soil Moisture Sensors in Agriculture: A Review
Application of Soil Moisture Sensors in Agriculture: A ReviewApplication of Soil Moisture Sensors in Agriculture: A Review
Application of Soil Moisture Sensors in Agriculture: A ReviewAnchit Garg
 

What's hot (20)

Optical MEMS
Optical MEMSOptical MEMS
Optical MEMS
 
P 6168--microcontroller based-lpg_gas_detector_using_gsm_module
P 6168--microcontroller based-lpg_gas_detector_using_gsm_moduleP 6168--microcontroller based-lpg_gas_detector_using_gsm_module
P 6168--microcontroller based-lpg_gas_detector_using_gsm_module
 
AUTONOMOUS LPG GAS SENSOR BOT USING ARDUINO ppt
AUTONOMOUS LPG GAS SENSOR BOT USING ARDUINO pptAUTONOMOUS LPG GAS SENSOR BOT USING ARDUINO ppt
AUTONOMOUS LPG GAS SENSOR BOT USING ARDUINO ppt
 
29. how does a thermal printer work.pdf
29. how does a thermal printer work.pdf29. how does a thermal printer work.pdf
29. how does a thermal printer work.pdf
 
Lecture 02 history & characteristics of mems
Lecture 02   history & characteristics of memsLecture 02   history & characteristics of mems
Lecture 02 history & characteristics of mems
 
LPG Gas detector
LPG Gas detectorLPG Gas detector
LPG Gas detector
 
75600403 automatic-plant-irrigation-system
75600403 automatic-plant-irrigation-system75600403 automatic-plant-irrigation-system
75600403 automatic-plant-irrigation-system
 
Arduino uno
Arduino unoArduino uno
Arduino uno
 
Gas & smoke detector Report
Gas & smoke detector ReportGas & smoke detector Report
Gas & smoke detector Report
 
Automatic Irrigation System
Automatic Irrigation SystemAutomatic Irrigation System
Automatic Irrigation System
 
Gas Leakage Detector using Arduino with SMS Alert - Engineering Project
Gas Leakage Detector using Arduino with SMS Alert - Engineering ProjectGas Leakage Detector using Arduino with SMS Alert - Engineering Project
Gas Leakage Detector using Arduino with SMS Alert - Engineering Project
 
Temp based fan speed control
Temp based fan speed controlTemp based fan speed control
Temp based fan speed control
 
Microcontroller Based LPG Detector Using GSM Module
Microcontroller Based LPG Detector Using GSM ModuleMicrocontroller Based LPG Detector Using GSM Module
Microcontroller Based LPG Detector Using GSM Module
 
Tracking system on IOT
Tracking system on IOTTracking system on IOT
Tracking system on IOT
 
Introduction to Arduino & Robotics
Introduction to Arduino & Robotics Introduction to Arduino & Robotics
Introduction to Arduino & Robotics
 
DHT11 Digital Temperature and Humidity Sensor
DHT11 Digital Temperature and Humidity SensorDHT11 Digital Temperature and Humidity Sensor
DHT11 Digital Temperature and Humidity Sensor
 
1_MEMS - Introduction.pdf
1_MEMS - Introduction.pdf1_MEMS - Introduction.pdf
1_MEMS - Introduction.pdf
 
gsm based Voting system
gsm based Voting system gsm based Voting system
gsm based Voting system
 
IRJET- Forest Fire Detection and Alerting System
IRJET- Forest Fire Detection and Alerting SystemIRJET- Forest Fire Detection and Alerting System
IRJET- Forest Fire Detection and Alerting System
 
Application of Soil Moisture Sensors in Agriculture: A Review
Application of Soil Moisture Sensors in Agriculture: A ReviewApplication of Soil Moisture Sensors in Agriculture: A Review
Application of Soil Moisture Sensors in Agriculture: A Review
 

Viewers also liked

Humidity inicator and controller
Humidity inicator and controllerHumidity inicator and controller
Humidity inicator and controllerAnaswara sasi
 
TEMPERATURE-HUMIDITY CONTROLLER WITH FIRE DETECTOR
TEMPERATURE-HUMIDITY CONTROLLER WITH FIRE DETECTORTEMPERATURE-HUMIDITY CONTROLLER WITH FIRE DETECTOR
TEMPERATURE-HUMIDITY CONTROLLER WITH FIRE DETECTORanjali577
 
Controlling Relative Humidity and Condensation in a CO2 Incubator
Controlling Relative Humidity and Condensation in a CO2 IncubatorControlling Relative Humidity and Condensation in a CO2 Incubator
Controlling Relative Humidity and Condensation in a CO2 Incubatorthebakerco
 
GMP Sub Part A & B
GMP Sub Part A & BGMP Sub Part A & B
GMP Sub Part A & BHARDIK PATEL
 
B. S. K. Technologies, Secunderabad, Humidity Meters
B. S. K. Technologies, Secunderabad, Humidity MetersB. S. K. Technologies, Secunderabad, Humidity Meters
B. S. K. Technologies, Secunderabad, Humidity MetersIndiaMART InterMESH Limited
 
industrial sterilization
industrial sterilizationindustrial sterilization
industrial sterilizationNilesh Utpure
 
Polymer and web component
Polymer and web componentPolymer and web component
Polymer and web componentImam Raza
 
Dm water conservation
Dm water conservationDm water conservation
Dm water conservationDilip Kumar
 
Validation Theory And Application 3
Validation   Theory And Application 3Validation   Theory And Application 3
Validation Theory And Application 3antoi alvarez
 
Humidity-Measuremente
Humidity-MeasurementeHumidity-Measuremente
Humidity-MeasurementeAree Salah
 
Types of ac and humidity control
Types of ac and humidity controlTypes of ac and humidity control
Types of ac and humidity controlAnanth Kumar M
 
A presentation on regulatory guidelines for photostability testing
A presentation on regulatory guidelines for photostability testingA presentation on regulatory guidelines for photostability testing
A presentation on regulatory guidelines for photostability testingzaartab
 
Unit 6 Water Content Determination and Moisture analysis
Unit 6   Water Content Determination and Moisture analysisUnit 6   Water Content Determination and Moisture analysis
Unit 6 Water Content Determination and Moisture analysisMalou Mojares
 
An Innovative Approach for Humidity Control by Using Deliquescent Materials i...
An Innovative Approach for Humidity Control by Using Deliquescent Materials i...An Innovative Approach for Humidity Control by Using Deliquescent Materials i...
An Innovative Approach for Humidity Control by Using Deliquescent Materials i...IJMER
 

Viewers also liked (20)

Humidity inicator and controller
Humidity inicator and controllerHumidity inicator and controller
Humidity inicator and controller
 
Temperature & humidity control cabinet
Temperature & humidity control cabinetTemperature & humidity control cabinet
Temperature & humidity control cabinet
 
TEMPERATURE-HUMIDITY CONTROLLER WITH FIRE DETECTOR
TEMPERATURE-HUMIDITY CONTROLLER WITH FIRE DETECTORTEMPERATURE-HUMIDITY CONTROLLER WITH FIRE DETECTOR
TEMPERATURE-HUMIDITY CONTROLLER WITH FIRE DETECTOR
 
Controlling Relative Humidity and Condensation in a CO2 Incubator
Controlling Relative Humidity and Condensation in a CO2 IncubatorControlling Relative Humidity and Condensation in a CO2 Incubator
Controlling Relative Humidity and Condensation in a CO2 Incubator
 
Air fuel technique
Air fuel techniqueAir fuel technique
Air fuel technique
 
GMP Sub Part A & B
GMP Sub Part A & BGMP Sub Part A & B
GMP Sub Part A & B
 
B. S. K. Technologies, Secunderabad, Humidity Meters
B. S. K. Technologies, Secunderabad, Humidity MetersB. S. K. Technologies, Secunderabad, Humidity Meters
B. S. K. Technologies, Secunderabad, Humidity Meters
 
industrial sterilization
industrial sterilizationindustrial sterilization
industrial sterilization
 
Polymer and web component
Polymer and web componentPolymer and web component
Polymer and web component
 
Gmp
GmpGmp
Gmp
 
Dm water conservation
Dm water conservationDm water conservation
Dm water conservation
 
Validation Theory And Application 3
Validation   Theory And Application 3Validation   Theory And Application 3
Validation Theory And Application 3
 
Measuring humidity
Measuring humidityMeasuring humidity
Measuring humidity
 
Humidity-Measuremente
Humidity-MeasurementeHumidity-Measuremente
Humidity-Measuremente
 
Types of ac and humidity control
Types of ac and humidity controlTypes of ac and humidity control
Types of ac and humidity control
 
A presentation on regulatory guidelines for photostability testing
A presentation on regulatory guidelines for photostability testingA presentation on regulatory guidelines for photostability testing
A presentation on regulatory guidelines for photostability testing
 
Unit 6 Water Content Determination and Moisture analysis
Unit 6   Water Content Determination and Moisture analysisUnit 6   Water Content Determination and Moisture analysis
Unit 6 Water Content Determination and Moisture analysis
 
Humidity
HumidityHumidity
Humidity
 
Sterilization methods
Sterilization methodsSterilization methods
Sterilization methods
 
An Innovative Approach for Humidity Control by Using Deliquescent Materials i...
An Innovative Approach for Humidity Control by Using Deliquescent Materials i...An Innovative Approach for Humidity Control by Using Deliquescent Materials i...
An Innovative Approach for Humidity Control by Using Deliquescent Materials i...
 

Similar to Humidity controller

51790954 green-house-environment-control
51790954 green-house-environment-control51790954 green-house-environment-control
51790954 green-house-environment-controlGherghescu Gabriel
 
Green-house-environment-control
 Green-house-environment-control Green-house-environment-control
Green-house-environment-controlGherghescu Gabriel
 
SiriusT3 Brochure
SiriusT3 BrochureSiriusT3 Brochure
SiriusT3 BrochureJon Mole
 
Air Humidity is crucial!
 Control and monitoring solution for mission-critica...
Air Humidity is crucial!
 Control and monitoring solution for mission-critica...Air Humidity is crucial!
 Control and monitoring solution for mission-critica...
Air Humidity is crucial!
 Control and monitoring solution for mission-critica...CAREL Industries S.p.A
 
Development and Scale Up Of a Chemical Process in Pharmaceutical Industry: A ...
Development and Scale Up Of a Chemical Process in Pharmaceutical Industry: A ...Development and Scale Up Of a Chemical Process in Pharmaceutical Industry: A ...
Development and Scale Up Of a Chemical Process in Pharmaceutical Industry: A ...IJERA Editor
 
2012 Critical Issues Summit Energy Panel, Part III
2012 Critical Issues Summit Energy Panel, Part III2012 Critical Issues Summit Energy Panel, Part III
2012 Critical Issues Summit Energy Panel, Part IIISFMI
 
How to choose a humidity sensor
How to choose a humidity sensorHow to choose a humidity sensor
How to choose a humidity sensorSherry Huang
 
Wireless Measurement and Control - AIChE New Orleans
Wireless Measurement and Control - AIChE New OrleansWireless Measurement and Control - AIChE New Orleans
Wireless Measurement and Control - AIChE New OrleansJim Cahill
 
Embedded green house automation system
Embedded green house automation systemEmbedded green house automation system
Embedded green house automation systemgajula vijaya lakshmi
 
Eco-Tex Ag Solutions Agriculture Slide Show 112012 Abrv
Eco-Tex Ag Solutions Agriculture Slide Show 112012 AbrvEco-Tex Ag Solutions Agriculture Slide Show 112012 Abrv
Eco-Tex Ag Solutions Agriculture Slide Show 112012 AbrvRoyalMav
 
Odour Regulation-Solution to control Odour from Municipal Solid Waste Managem...
Odour Regulation-Solution to control Odour from Municipal Solid Waste Managem...Odour Regulation-Solution to control Odour from Municipal Solid Waste Managem...
Odour Regulation-Solution to control Odour from Municipal Solid Waste Managem...Karthik Kumar
 
Humidity sensor
Humidity sensorHumidity sensor
Humidity sensorlanjot
 
Development of Pfizer's Third Generation Turbidimetric Solubility Assay - An ...
Development of Pfizer's Third Generation Turbidimetric Solubility Assay - An ...Development of Pfizer's Third Generation Turbidimetric Solubility Assay - An ...
Development of Pfizer's Third Generation Turbidimetric Solubility Assay - An ...Brian Bissett
 
5128A RHapid-Cal Humidity Generator Brochure
5128A RHapid-Cal Humidity Generator Brochure5128A RHapid-Cal Humidity Generator Brochure
5128A RHapid-Cal Humidity Generator BrochurePT. Siwali Swantika
 

Similar to Humidity controller (20)

Preliminary Trial: The WeedSeeker
Preliminary Trial: The WeedSeekerPreliminary Trial: The WeedSeeker
Preliminary Trial: The WeedSeeker
 
Lecture 9b scaling up
Lecture 9b   scaling upLecture 9b   scaling up
Lecture 9b scaling up
 
51790954 green-house-environment-control
51790954 green-house-environment-control51790954 green-house-environment-control
51790954 green-house-environment-control
 
Green-house-environment-control
 Green-house-environment-control Green-house-environment-control
Green-house-environment-control
 
SiriusT3 Brochure
SiriusT3 BrochureSiriusT3 Brochure
SiriusT3 Brochure
 
Air Humidity is crucial!
 Control and monitoring solution for mission-critica...
Air Humidity is crucial!
 Control and monitoring solution for mission-critica...Air Humidity is crucial!
 Control and monitoring solution for mission-critica...
Air Humidity is crucial!
 Control and monitoring solution for mission-critica...
 
Development and Scale Up Of a Chemical Process in Pharmaceutical Industry: A ...
Development and Scale Up Of a Chemical Process in Pharmaceutical Industry: A ...Development and Scale Up Of a Chemical Process in Pharmaceutical Industry: A ...
Development and Scale Up Of a Chemical Process in Pharmaceutical Industry: A ...
 
Choosing a Laboratory CO2 Incubator
Choosing a Laboratory CO2 IncubatorChoosing a Laboratory CO2 Incubator
Choosing a Laboratory CO2 Incubator
 
Gordon Sharp Handout
Gordon Sharp HandoutGordon Sharp Handout
Gordon Sharp Handout
 
Moisture measurement
Moisture measurementMoisture measurement
Moisture measurement
 
A REVIEW ON GREENHOUSE ENVIRONMENT CONTROLLING ROBOT
A REVIEW ON GREENHOUSE ENVIRONMENT CONTROLLING ROBOTA REVIEW ON GREENHOUSE ENVIRONMENT CONTROLLING ROBOT
A REVIEW ON GREENHOUSE ENVIRONMENT CONTROLLING ROBOT
 
2012 Critical Issues Summit Energy Panel, Part III
2012 Critical Issues Summit Energy Panel, Part III2012 Critical Issues Summit Energy Panel, Part III
2012 Critical Issues Summit Energy Panel, Part III
 
How to choose a humidity sensor
How to choose a humidity sensorHow to choose a humidity sensor
How to choose a humidity sensor
 
Wireless Measurement and Control - AIChE New Orleans
Wireless Measurement and Control - AIChE New OrleansWireless Measurement and Control - AIChE New Orleans
Wireless Measurement and Control - AIChE New Orleans
 
Embedded green house automation system
Embedded green house automation systemEmbedded green house automation system
Embedded green house automation system
 
Eco-Tex Ag Solutions Agriculture Slide Show 112012 Abrv
Eco-Tex Ag Solutions Agriculture Slide Show 112012 AbrvEco-Tex Ag Solutions Agriculture Slide Show 112012 Abrv
Eco-Tex Ag Solutions Agriculture Slide Show 112012 Abrv
 
Odour Regulation-Solution to control Odour from Municipal Solid Waste Managem...
Odour Regulation-Solution to control Odour from Municipal Solid Waste Managem...Odour Regulation-Solution to control Odour from Municipal Solid Waste Managem...
Odour Regulation-Solution to control Odour from Municipal Solid Waste Managem...
 
Humidity sensor
Humidity sensorHumidity sensor
Humidity sensor
 
Development of Pfizer's Third Generation Turbidimetric Solubility Assay - An ...
Development of Pfizer's Third Generation Turbidimetric Solubility Assay - An ...Development of Pfizer's Third Generation Turbidimetric Solubility Assay - An ...
Development of Pfizer's Third Generation Turbidimetric Solubility Assay - An ...
 
5128A RHapid-Cal Humidity Generator Brochure
5128A RHapid-Cal Humidity Generator Brochure5128A RHapid-Cal Humidity Generator Brochure
5128A RHapid-Cal Humidity Generator Brochure
 

Humidity controller

  • 1. 1 Darwish Al-Arafati 86949 Nasr Al-Abdali 86996
  • 2. Introduction • Project Overall (Problem, Specifications and Constraints). • Project Design and its principle. • Sensor Specifications. • Project and market Product Comparison. • Conclusion • References 2
  • 3. Project Objective: In the greenhouse the humidity level is very important as a very humid atmosphere may be harmful to some plants because the rate of transpiration and evaporation is reduced in a very humid conditions, and these plants my suffer damage from overheating unless you use the ventilation to bring into the greenhouse cooler and drier air. On the other hand, many tropical plants from native humid climates require high levels of humidity for a healthy growth and will not survive in a dry atmosphere. That is why Controlling Humidity needed!. Introduction: One of the biggest challenges in maintaining a greenhouse is humidity control. Most plants enjoy a humidity of 50 to 60 percent, and this is a challenge to manage at times. The main goal is to avoid condensation on plants, which promotes mold and fungus growth. Low humidity leads to leaf dehydration, more frequent watering and pest infestation. 3
  • 4. 1 Problem Statement 2 Constraints Economical:[ Total Cost is equal Nearly 8$] Humidity level in Green Environmental: No Impact Health and Safety: It does not Houses may affect plants affect them. growth.. Social and Cultural: System is acceptable. Performance: Fast System Response 3 Specifications •Performance: Accurate and It has Very Fast Response.... •Functionality: System Will check Voltage across the Sensor ,so valid action will be done •Operational: System can work on the environment on which temperature lie between 10 to 60°C. 4
  • 5. How Does it work?!! 230 Vac 1k Ohms 5
  • 6. Project Cost Component Name Cost HS 1101 (HUMIDITY SENSOR) 4.6 2 Comparators Operational Amplifier 1.36$ 2 Relays 1.4$ 4 Resistors 0.4$ Total Cost 7.76$ 1$≈0.385 O.R 6
  • 8. Farm Greenhouse Humidity Controller Product Compared With Project Design Comparison Side Project/ Greenhouse Farm Greenhouse Humidity Humidity Controller Controller Resolution Lower Higher Measuring range +0.1% RH/°C +1% RH/°C 10 to 60°C -40C~+85C Cost 8$ 35$ 8
  • 9. How to Improve Design? •Using accurate components. •Highly Sensitive Humidity sensor. •Using Microcontroller instead of Comparators. •Avoid using long wires and poor cables. 9
  • 10. Conclusion: Humidity can be controlled easily using 2 comparators with few resistors and a sensor.45% of Humidity is perfect one for plants growth. By means of Humidity Absorption and Air Humidifier, Humidity is going to be controllable and being balanced to be 45% in the air. References -http://www.ehow.com/how_2107526_manage-humidity-greenhouse.html -http://fogco.com/applications/greenhouse -http://www.ryanguitars.com/NewsandEvents/Guitar_tech_tips/Humidity_Chart.htm 10