Greenhouses, Nurseries and Glasshouses
It is essential to keep a controlled climate in the greenhouses – no matter the dimensions of the structure or the season. During the summertime, low relative humidity may be avoided using Igloo misting systems. Also, excessive heat will be defeated by the very same misting systems, due to the principle of the evaporative cooling.
During the wintertime the humidity is kept at the right level – dehydration of the crops caused by the heating systems is avoided.
The delicate touch of water droplets (under 10 microns diameter!) is perfect for the most pretentious crops. The growers usually complain because the low humidity and high temperatures in the greenhouses. At low levels of humidity, plants slow/halt the growing process.
Benefits using misting systems:
- The productivity of the greenhouse is increased by speeding up the plants growth
- Controlled climate in any season
- Lower water consumption for the irrigation
- Humidity levels are constant
- DIY installation, using easy, modular kits in various configurations – you can choose the perfect solution for your needs!
- Low energy costs
- Very easy and cheap maintenance
It is an undisputed fact that control of humidity provides qualitytive as well as commercial advantages in nursery business.
The usual applications are propagation techniques where seedlings or cuttings are propagated (vegetative propagation) – maybe not so well known are applications for sales areas or breeding beds.
The following possibilities are reviewed:
The shown examples are sales areas in glasshouses. The water – provided by our humidification system – will not cover the total water need of the plants on sale; however their appearance in these sales areas are much better.
The plants stay fresh for a longer period, the leaves show more intensive colors. Moreover the sales area provides a fresh climate, comfortable to all visitors. According to the chosen control settings the fogging can be set to morning dew (following sunrise) as well as during the day with an interval control system able to adapt to all timing needs; another option is control by hygrostat. The fogging system operates automatically and can be utilized round the week (also on closing days) by means of a 24-hour clock-system. If the fogging nozzles are mounted on a high level and the timing interval is set to short but effective intervals no moisture will befall the customers – usually they regard the fogging effect as dramatic and interesting. With little effort small jungle-scenarios can be constructed in the sales area – simulating cloud-forest landscapes where fog is drifting over water.
One limitation however arises: plants in bud should be placed at somewhat different locations – due to the perfect climate they would blossom too fast.
Cooling and Climatization
By evaporating microscopic fog droplets in hot dry air the surrounding air can be cooled considerably. This effect – in physics called “adiabatic cooling” or “evaporation cooling” – can be applied in areas where plant-production during the hot summer-season is desired but virtually impossible.
To provide the optimal cooling effects some criteria have to be fulfilled – which are listed synoptically:
- The fog droplets have to be extremely small to be able to hover, this means a doplet size of maximal 30 micron (= 0,03 mm diameter).
- Simple fogging will result in a damp hothouse climate, therefore substantial air exchange must be provided; ideally a total exchange of the air volume every minute. The higher the outside (intake) air temperature the smaller the cooling effects.
- Any gardener will know that each plant – according to its individual profile – will grow actively only up to a certain temperature. A lesser known fact is that this temperature can be surpassed with rising humidity.
- The most important parameter is the temperature on the leaf-surface, not the surrrounding air temperature. Test-series have proven that the surface-temperature of the leaves can be as much as 10°C lower as the surrounding air !
- The cooling effects of fogging in a glasshouse can create thermic air circulations, if the fogging nozzles are placed optimally. (please refer also to “air movement in a humidified space”).
If all these conditions can be met the following improvements can be guaranteed:
- With outside temperatures of more than 40°C and a relative humidity of 40-45 % humidification inside a glasshouse near the saturation point (90-95% relative humidity) the inside air temperature will be reduced to at least 30°C. As leaf-temperature will be even lower, active plant-growth is still no problem.
- This cooling principle will work even better in really hot climates (above 42°C) as experienced in areas in Africa or Middle East, where the relative humidity of intake-air is considerably lower (for instance in parts of Saudi Arabia or Iran as low as 15-20% relative)
- Summer temperatures in Central Europe are usually below 32°C even on extreme summer days – therefore in most cases the installation of fans is not necessary.
- Intensive fogging with increased statis ventilation (open side- or top-flaps) can prevent burning of the plants very effectively. (Limitation – in coastal areas of hot countries where summer brings high humidity of up to 80% the described methods of cooling can become ineffective .)
- In addition we want to mention that slight shading decreases heat intake by radiation; the hovering fog droplets accomplish this effect without any other means.
Fungicides, Pesticides, Fertilizer and other additives are necessary but cost-intensive. Application should be as effective as possible. If these additives can be applied in liquid form their application can be accomplished with a fogging system. This method provides several advantages :
- Application can be accomplished fully automated with our fogging plants
- No personal observation is needed
- The hovering fog, which penetrates even dense foliage, provides highly effective application
Example: Glasshouse for Anthurium mother-plants in the “Municipal Reserve Gardens” Vienna
The responsible gardeners report that they had to perform up to 6 sprayings a year by conventional methods. After switching application to the fogging system only two applications with a reduction of the needed spraying material to approximately the 1/6 part of the original amount!