Are Dehumidifier Water Meters Essential for Greenhouses and Grow Rooms?
The water balance of a greenhouse, or any growing space, is one of the main ways to measure and understand plant activity. The only way to truly gauge the water balance of your growing space, is by using flow meters to measure all your inputs and outputs, including a dehumidifier water meter. This is an integral part of plant empowerment, as well.
What is the Water Balance of a Greenhouse or Grow Room?
The water cycle is comprised of 2 interrelated balances – the water balance within the plant and the moisture balance of the space itself.
The plant’s water balance
Plants take in water through their roots, running it up the plant before releasing it from the stomate, during photosynthesis or respiration. While plants do consume some water, they release more than 90% of the water they take in, as water vapor.
Plant water input = water taken in through the roots
Plant water output = water vapor released by the leaves
The greenhouse moisture balance
This refers to the air inside the greenhouse or indoor grow room. Moisture is simply water vapor in the air. It’s released by the plants, as described above, and evaporated from the soil. Both of which raise the humidity in the space.
Greenhouse moisture input = water vapor transpired by plants and evaporated from the soil
Greenhouse moisture output = water vapor released through ventilation or extracted with a dehumidifier
The overall water balance of a greenhouse or grow room
While these processes are different, they’re actually two parts of the overall greenhouse water cycle, which should, optimally, be balanced.
When looking at the greenhouse or grow room as a whole, we can break down the water cycle down into simple inputs and outputs:
Overall water input = irrigation
Overall water output = drainage + moisture extracted by dehumidifier + moisture released through ventilation
The Importance of a Balanced Water Cycle
Keeping the water balance in check is critical for plant growth, health and development. If the water cycle isn’t balanced, you may experience either very high, persistent humidity (low VPD), or very low relative humidity levels (high VPD).
High Humidity – Low VPD
For most growers, the only water they introduce to the system is irrigation. After deducting drainage, most of the irrigation water eventually turns into humidity.
So, if you aren’t extracting enough water, your humidity will continue to rise, which may slow down plant growth and fruit development.
Low Humidity – High VPD
Low humidity, or high VPD, will occur if your irrigation isn’t enough for your plants, or when your dehumidifiers operate unnecessarily.
When plants don’t receive enough water, they enter a state of stress, in which they slow down or stop their photosynthesis and respiration. They do this by keeping their stomate closed, to retain water. This means they aren’t releasing any moisture.
When plants undergo this kind of stress, they inhibit their own growth and development and become more susceptible to diseases, as their immune system weakens.
Both situations are harmful and inefficient, but they aren’t always easy to detect. It’s especially difficult to notice low humidity before it becomes physically apparent in the plants. Therefore, using water meters to measure your water cycle is critical.
Using Dehumidifier Water Meters to Understand Your Plants
Monitoring is at the heart of greenhouse management. It’s practically impossible to truly understand what’s going on in the space without proper measurement tools.
So, using a dehumidifier water meter is the only way to really understand your water balance. In turn, letting you optimize by increasing or decreasing irrigation, or adjusting dehumidification.
Most growers meter their irrigation water and drainage, which accounts for much of the water. But it’s still rare to find a greenhouse that meters humidity extraction – the missing piece of the puzzle.
Most growers don’t really know whether their water cycle is balanced or not, until they feel the negative effects.
The Benefits of Using a Dehumidifier Water Meter
Using a water meter to measure the water your dehumidifier extracts is critical if you want to optimize growth and efficiency. When dehumidification is your only method of humidity control, then the water it removes should be similar to your irrigation input, minus your drainage (a bit less, as plants do consume a small percentage).
If your dehumidifiers are extracting water at the expected rate, but your humidity is still high or rising, you may need more dehumidification power.
If your dehumidifiers work properly, yet aren’t extracting water at the expected rate, you’ll know that your plants haven’t been transpiring as they should. This should raise a red flag, as your plants aren’t receiving enough water! Without metering the water your dehumidifiers extract, this is almost impossible to figure out, before plants start showing signs of stress.
Using SmartDG for Dehumidifier Water Metering
While most water meters will get the job done, DryGair has developed the SmartDG water meter and monitoring interface, for our dehumidifiers. The system lets growers monitor their outgoing water locally or remotely, in real-time.
The SmartDG system includes much more than just a water meter, and has several advantages for professional growers:
- Monitor water extraction
- Control DryGair units and configure relative humidity and temperature set points
- Monitor relative humidity and temperature (including real-time VPD and dew point monitoring)
- Monitor the dehumidifier compressor’s operation and accumulative runtime
- View daily, weekly or monthly data – downloadable as graphs as well
Contact us for more information on SmartDG and humidity control.