The protected greenhouse environment The greenhouse environment is designed to allow plants to perform close to their genetic optimum so that the grower achieves maximum profit. A greenhouse is designed so that the plant converts sunlight, water and CO2 and minerals into marketable yield. Thus the protected greenhouse environment creates a "cozy" climate inside a [...]
Heating the nutrient solution of a NFT hydroponic system may sound like a lucrative option for early yields. Tampering with the nutrient solution temperature is expensive and return on investment low. It is as if the protected environment provides growers endless possibilities to manipulate the growth season of their crops. Unfortunately nature does not work [...]
Greenhouse heating can be very expensive, especially if you greenhouse is not optimally set up for heating. There are factors that can be taken into account in order to reduce greenhouse heating cost or capital installation cost. (A lot more info is in The Polytunnel Book) Reduce air leakages It is estimated that 10-30% of heat in [...]
The effectiveness of a pad and fan system will not only depend on the design, but also on the wet bulb temperature outside the greenhouse. It is not the relative humidity, as many grower think that determine the effectiveness of the pad and fan system. The wet bulb temperature will determine to what temperature the [...]
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 greenhouse cladding should be sprayed [...]
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 of the material. All insect [...]
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 sufficiently. One of the latest [...]
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 evaporative pad. Considering the cost [...]
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 and fan” systems because the [...]
