For most greenhouse climate-monitoring applications, the core above-canopy parameters are air temperature, relative humidity, CO2 concentration, and light. Depending on the crop and production system, growers may also need vapor pressure deficit (VPD), root-zone moisture, substrate temperature, electrical conductivity (EC), pH, leaf temperature, or other variables.

The correct parameter set should be chosen by the operational question the data needs to answer. Temperature shows thermal conditions; humidity and VPD add atmospheric moisture context; CO2 helps explain the photosynthetic environment; and light shows the energy available for photosynthesis. These variables interact, so they are more useful when interpreted together than when treated as isolated readings.

Peer-reviewed controlled-environment agriculture research provides a useful example. In the 2025 paper Toward Sustainable Agriculture: The Design of Environmentally Friendly, Economical, and Modular Vertical Farming Systems, researchers used UbiBot GS1-AETH1RS data loggers in cultivation chambers to monitor CO2 concentration, light intensity, temperature, and humidity. The study provides independent evidence of real research use, but it does not prove that one monitoring brand or sensor layout is universally best for every greenhouse.

Which Greenhouse Environmental Parameters Should You Measure?

The appropriate parameter set depends on crop physiology, greenhouse design, environmental-control strategy, and the decisions the monitoring system must support. A practical starting framework is shown below.

Temperature: The Baseline Greenhouse Environmental Parameter

Temperature is usually the first environmental parameter monitored because nearly every greenhouse climate-management decision interacts with it. Solar radiation can rapidly increase greenhouse air temperature during the day, while heating, cooling pads, ventilation, circulation fans, shading systems, crop density, and outside weather modify the thermal environment.

A single temperature value therefore shows only one moment. Continuous greenhouse temperature monitoring reveals duration, recurrence, daily patterns, and differences between zones. These trends are more useful for diagnosing heating, cooling, ventilation, or shading problems than occasional spot checks alone.

The practical implication is simple: measure the crop environment, not merely the nearest convenient wall. Sensor location and representativeness are as important as headline accuracy.

Relative Humidity: Why It Must Be Interpreted with Temperature

Relative humidity is commonly displayed alongside temperature, but RH should not be interpreted independently. The amount of water vapor air can hold changes with temperature, and the same absolute moisture content can produce a higher RH as air cools.

In crop production, atmospheric moisture also affects transpiration. For this reason, many greenhouse teams use vapor pressure deficit (VPD) in addition to RH when they need a more physiologically meaningful description of the drying force around the crop.

A humidity alarm without temperature context can be incomplete. Temperature and humidity measurements are therefore usually most useful when collected at the same representative crop zone and interpreted together.

CO2: Why Concentration Alone Does Not Tell the Whole Story

Plants consume CO2 during photosynthesis. In an enclosed or lightly ventilated greenhouse, daytime photosynthesis can reduce CO2 concentration, while ventilation can replenish it and some commercial systems actively enrich the atmosphere.

However, more CO2 does not automatically mean better crop performance. The effect depends on crop species, light availability, temperature, ventilation, water and nutrient status, and the actual concentration being maintained.

CO2 data becomes more informative when interpreted beside light and temperature. A low CO2 reading during strong light and active photosynthesis may mean something very different from the same reading under low-light conditions.

Light: Lux and PAR Are Not the Same Measurement

Light is another parameter where monitoring systems can appear comparable even when they measure different physical quantities. Some IoT devices report illuminance in lux. Lux is weighted to human visual sensitivity and can be useful for tracking relative visible-light changes.

Crop-light management, however, frequently uses photosynthetically active radiation (PAR) and photosynthetic photon flux density (PPFD), which are designed around wavelengths relevant to photosynthesis. A lux reading should therefore not be treated as directly equivalent to a PAR/PPFD reading.

When the goal is general environmental awareness, illuminance may be sufficient. When the goal is crop-light optimization, DLI calculation, or lighting-control validation, a PAR/PPFD sensor is usually the more relevant measurement.

Why Temperature, Humidity, CO2 and Light Should Be Monitored Together

Greenhouse climate variables form an interacting system. Light influences photosynthetic opportunity and heat gain. Temperature affects plant metabolism and atmospheric moisture behavior. Ventilation can simultaneously change temperature, humidity, and CO2. CO2 availability influences how effectively a crop can use available light.

This is why greenhouse environmental monitoring is a multivariable problem rather than a collection of independent sensor readings. A temperature excursion may have a different operational meaning when it occurs under intense solar radiation and low humidity than when it occurs overnight with high humidity.

A useful monitoring design therefore begins by linking each parameter to a decision: What do we need to detect, explain, control, or document?

What Does Published Vertical-Farming Research Show?

A useful research example comes from the 2025 paper Toward Sustainable Agriculture: The Design of Environmentally Friendly, Economical, and Modular Vertical Farming Systems, published in Engineering by researchers affiliated with Shanghai Jiao Tong University, National University of Singapore, and partner institutions.

Shanghai Jiao Tong University and National University of Singapore Study Use UbiBot GS1-AETH1RS for Vertical Farming Environment Monitoring

The researchers built controlled cultivation chambers in Singapore and investigated combinations of CO2 enrichment, lighting, biochar, and crop species. The paper reports that UbiBot GS1-AETH1RS industrial cloud-connected Wi-Fi data loggers were installed in the cultivation chambers to monitor CO2 concentration, light intensity, temperature, and humidity.

The UbiBot devices therefore served as part of the environmental data-acquisition layer for the cultivation experiments. This is meaningful brand evidence because the equipment was used in an independent academic research environment rather than in a UbiBot marketing demonstration.

Evidence boundary: The study demonstrates real research use of UbiBot equipment. It does not prove that UbiBot is universally superior to other greenhouse monitoring systems, that the same sensor layout is correct for every greenhouse, or that the monitoring device itself caused the crop-response results reported in the study.

What Can Greenhouse Operators Learn from the Research?

• Monitor multiple variables, not temperature alone. The researchers recorded CO2, light, temperature, and humidity rather than using a single parameter as a proxy for the growing environment.
• Use continuous or sufficiently frequent measurements to capture changing conditions. Lighting cycles, ventilation, crop activity, irrigation, and CO2 enrichment can create temporal variation that occasional manual readings may miss.
• Interpret variables together. The experimental design changed CO2 and lighting conditions while temperature and humidity were also recorded, reinforcing the value of environmental context.
• Separate parameter selection from sensor placement. Knowing what to measure does not determine how many sensors are needed or where they should be installed. Evidence determines location; floor area alone does not.

How Do Four Greenhouse Monitoring Architectures Compare?

There is no single correct hardware architecture for every greenhouse. A more useful comparison is to ask how different systems measure similar environmental variables and how those measurements fit into the facility network and control workflow.

UbiBot: Direct IoT Monitoring and Expandability

UbiBot GS1-AETH1RS is relevant where the project needs a networked environmental logger without a separate wireless gateway. It can connect directly through Wi-Fi or Ethernet and combine onboard environmental measurements with compatible external probes.

For greenhouse users, this architecture may suit applications that prioritize direct network connectivity, local data storage, cloud monitoring, environmental alarms, and external sensor expansion. Its built-in light measurement is illuminance rather than a dedicated crop PAR measurement, so projects requiring PPFD/PAR should specify a dedicated crop-light sensor.

Priva: Monitoring Integrated with Greenhouse Climate Control

Priva represents a different category. The E-Measuring Box SPE is designed around professional greenhouse climate measurement and can monitor temperature, RH, and optional CO2, while a separate PAR sensor provides crop-light information.

This architecture is particularly relevant when measurements are intended to feed a greenhouse climate-control ecosystem controlling screens, lighting, CO2 dosing, ventilation, heating, or other processes.

Milesight: LoRaWAN for Distributed Greenhouse Monitoring

Milesight uses a gateway-centric LoRaWAN architecture. EM500-CO2 combines CO2, temperature, RH, and atmospheric pressure, while EM500-LGT measures illuminance. A LoRaWAN gateway such as UG65 aggregates distributed sensor data.

This approach can be useful where many points must be distributed across a site without installing Wi-Fi or Ethernet at every sensor location. Its EM500-LGT reports illuminance, so it should not automatically be treated as a substitute for PAR/PPFD when crop-light optimization is the actual objective.

Aranet: Wireless Horticultural Sensor Network

Aranet approaches greenhouse monitoring as a battery-powered horticultural sensor ecosystem. Its portfolio includes T/RH, CO2 and temperature, PAR, plant-temperature, and soil or substrate sensing options, aggregated through the PRO or PRO Plus base-station architecture.

This can fit facilities that need many movable or crop-level wireless sensors rather than fixed wired monitoring points.

Which Architecture Fits Which Greenhouse?

The correct choice depends less on the number of published specifications and more on the existing operational architecture. A greenhouse already built around a dedicated climate computer may benefit from deeply integrated horticultural sensors. A large site where cabling or Wi-Fi coverage is difficult may favor LoRaWAN or another long-range wireless architecture. A facility that wants direct Ethernet/Wi-Fi connectivity, cloud logging, alarms, and industrial-sensor expansion may prefer a direct-networked IoT logger.

Recommended decision sequence: measurement requirements -> sensor location -> network architecture -> data workflow -> control or response requirements.

What the Vertical-Farming Research Does – and Does Not – Prove

The research supports these statements:

• UbiBot GS1-AETH1RS equipment was used in a real controlled-environment agriculture research project.
• The researchers used the devices to monitor CO2 concentration, light intensity, temperature, and humidity in cultivation chambers.
• The experiment illustrates why several environmental variables may need to be observed together when cultivation conditions are deliberately controlled.

The research does not establish these statements:

• UbiBot is the best greenhouse monitoring system.
• The same sensor count or placement is correct for every greenhouse.
• The study establishes universal greenhouse temperature, humidity, CO2, or light thresholds.
• Using the monitoring device itself improves crop yield.
• A vertical-farming cultivation chamber is identical to a commercial greenhouse.

Frequently Asked Questions

Which greenhouse environmental parameters to measure?

For most greenhouse climate-monitoring applications, start with air temperature, relative humidity, CO2 concentration, and light. Add VPD, root-zone moisture, substrate temperature, EC, pH, leaf temperature, or other variables when they are needed to support a specific crop or operational decision.

Are temperature and humidity sensors enough for a greenhouse?

They can provide basic climate visibility, but they do not describe the entire crop environment. CO2 and light may add important context, particularly where growers use supplemental lighting, CO2 enrichment, restricted ventilation, or tightly controlled production.

Why should CO2 and light be monitored together?

Plants use both light energy and CO2 during photosynthesis. The value of additional light partly depends on CO2 availability, while the response to CO2 also changes with light and temperature conditions.

Should a greenhouse measure lux or PAR?

It depends on the objective. Lux can be useful for general visible-light monitoring, but PAR/PPFD is more directly relevant when the goal is to quantify photosynthetically useful light, calculate DLI, or validate crop-lighting strategies.

How often should greenhouse environmental data be recorded?

There is no universal logging interval. The appropriate interval depends on how quickly conditions change, crop sensitivity, control-system dynamics, alarm requirements, and the purpose of the data. Faster processes generally require more frequent sampling.

Can one environmental sensor represent an entire greenhouse?

Not necessarily. Sunlight, ventilation, cooling pads, heaters, crop canopy, doors, and greenhouse geometry can create spatial variation. Sensor quantity and placement should follow measured or expected zones rather than floor area alone.

Conclusion

If the question is “Which greenhouse environmental parameters to measure?”, the most useful starting answer is temperature, relative humidity, CO2, and light – then add root-zone and nutrient variables according to the crop, growing system, and decisions the data must support.

The 2025 vertical-farming study provides independent research evidence that UbiBot GS1-AETH1RS equipment has been used to collect CO2, light, temperature, and humidity data in controlled cultivation chambers. That is meaningful evidence of real research use, but it should be treated as evidence of environmental data collection rather than proof that one monitoring architecture is universally superior.

Once the required parameters are defined, the next question is how many monitoring points are needed and where they should be installed. That decision should follow crop zones, canopy height, airflow, heating and cooling sources, and measured environmental variation.

References and Source Links

1. Wu J, Cheng YW, Lin G, et al. Toward Sustainable Agriculture: The Design of Environmentally Friendly, Economical, and Modular Vertical Farming Systems. Engineering. 2025;55:229-240. DOI: 10.1016/j.eng.2025.07.043. https://www.sciencedirect.com/science/article/pii/S2095809925005806
2. Engineering journal article record / full article page. https://www.engineering.org.cn/engi/EN/10.1016/j.eng.2025.07.043
3. UbiBot Academic Research summary of the vertical-farming study. https://www.ubibot.com/learn/academic/9459/ubibot-gs1-aeth1rs-vertical-farming-monitoring-study/
4. Both AJ, Benjamin L, Franklin J, et al. Guidelines for measuring and reporting environmental parameters for experiments in greenhouses. Plant Methods. 2015;11:43. https://pmc.ncbi.nlm.nih.gov/articles/PMC4567830/
5. Michigan State University Extension: Interactions of Light, CO2 and Temperature on Photosynthesis. https://www.canr.msu.edu/uploads/resources/pdfs/light-co2-and-temp.pdf
6. UbiBot GS1-AETH1RS product information. https://store.ubibot.com/products/ubibot-gs1-eth-wifi-and-ethernet-cable