Cooling a greenhouse can be just as expensive as heating, well almost. There are some very practical methods that you can use to save money. One of the cheapest methods are spraying the surface of plastic tunnels with soluble lime. Here is how. The surface of the [...]
Insect screens or thermal screens are designed to reduce heat in summer and increase temperatures during the night, but also to reduce the number of insects entering the production area. Various designs are available and each type is designed to keep certain insects out by varying the size of the holes and thickness [...]
Heat is always a problem in greenhouses during summer months and even during winter in some areas. Extreme high temperatures cause stress in plants and reduce yields, quality and increases pest and disease pressure thereby increasing costs. Overall, the economic viability of a greenhouse decreases if temperature is not controlled [...]
The installation of new evaporative pads is expensive. The material should last at least two years if not more. With good regular maintenance, evaporative pads should last 5 years. Fortunately the grower has the opportunity to spend very little money on small items which will increase the lifespan of the [...]
Pad-and-fan systems, also called evaporative pad-and-fan systems, is the most common method of cooling a greenhouse in warm weather regions. Although not optimal, it is better than no cooling at all. Using an evaporative pad-and-fan requires a fan mounted opposite the evaporative pads. Evaporative pad-and-fan systems are referred to as “pad [...]
Many growers have tried reducing temperatures (cooling) with fogging nozzles. The concept of spraying the air with microscopic water droplets which absorb the heat in the air sound right. However, fogging does not just decrease the temperature, it increases the humidity as well. A fogging system cannot operate efficiently if it [...]
Ventilation of greenhouses in humid tropical areas presents the grower with a complete new set of problems. There are various methods available but none have the desired effect. Screening is limited since it can only be applied during certain periods of the day and it limits the amount of sunlight [...]
Arid regions are characterized by low rainfall, low humidity and high temperatures during summer. The largest problem is temperature during the day time inside the tunnel during summer months. According to Arbel, Segal, et al. (1990), greenhouses found in arid areas have specific needs that should achieve the following: Low [...]
Ventilation is the exchange of air inside the greenhouse with air taken from outside the greenhouse using either natural or forced methods. Ventilation efficiency is critical in successful crop growth. The most common problem encountered in hot arid climates is to cool a greenhouses down in comparison with Northern Europe [...]
