Greenhouse climate control wet walls are used in climate controlled greenhouses, its an evaporative cooling system consisting of an array of evaporative cooling pads through which water is circulated using a pump. Fans on the opposite wall of the conditioned space draw air through the wet-wall, cooling it by means of the water evaporating from the pads. The wet-wall should be on the side of the building facing the prevailing wind or perpendicular to the prevailing wind directions, so as to minimise airflow resistance through the wet wall or against the fans.
In general, Greenhouse climate control wet walls are a type of evaporative cooling system that are more cost-effective to install for temperature control and operate than air conditioning. Greenhouse Wet walls consist of an array of evaporative cooling pads through which water is circulated using a pump. On the opposite wall, there are cooling fans that draw air through the wet wall, cooling it by means of the evaporation of water from the pads. The wet wall should be on the side of the building facing the prevailing wind.
Greenhouse Tunnels SA installs greenhouse climate control wet walls for climate controlled greenhouses, designing and professionally installing best operated evaporative cooling system increasing an evaporation efficiency of up to 85 percent. The temperature of the cooled air exiting an evaporative cooling pad is a function of the relative humidity of the outside air. With an outdoor relative humidity of 50% and temperature of 32°C, this evaporative cooling system typically reduces the temperature to 24°C
Temperatures can easily exceed 38°C in greenhouses during the summer if they are not equipped with cooling systems. Such high temperatures reduce crop quality and worker productivity. Evaporative cooling is the most common method for reducing the temperature inside a greenhouse. Air conditioning or refrigeration systems can be used, but their installation and operating costs are usually prohibitive
.
The coolest area of the greenhouse is adjacent to the evaporative cooling pads. As this cooled air moves along the length of the greenhouse it removes heat, which is expelled by the exhaust fans. When air connects with water, the water absorbs thermal energy from the air to evaporate. Evaporative cooling is your application of choice if you experience hot, dry summers. By introducing 100% fresh air into the conditioned space, you gain oxygen and eliminate odours.
Facts About Greenhouse Wet Walls
Owning wet walls in your greenhouse will be useful when the climate is drier, as this method works as an active cooler. They are most suitable when humidity levels are low in a hot climate
The design of the wet wall looks like a honeycomb and is made up of cellulose material to avoid degradation and the build-up of moss. The honeycomb design allows air to pass over the wet cooling pads.
The gutter at the top of the wall is where the water trickles down into a collection pipe, which then enters and passes through a filtration system and recirculates, making this an efficient and eco-friendly method of cooling greenhouses.
The combination of wet walls and extraction fans will reduce the temperature by 10 –15 degrees. On one side of the wall, a bank of wet walls is placed and on the other side is a bank of extraction fans. The fans blow air toward the evaporated water, thus creating a cooling system.
Create a hybrid system for extremely hot days! Use a wet wall during the day and natural aspiration in the evening.
Wet walls are mainly used by large commercial establishments due to the cost and the installation. The system requires foundational plumbing and a sophisticated setup, leading to a higher initial setup cost, but overall can be a very effective cooling method.
Cooling Your Greenhouse
As we’ve mentioned, it’s super important to control the temperature and humidity levels in your greenhouse to ensure your crops are healthy. While wet walls are an excellent solution for large, commercial growers, there are many other options to consider for your specific needs. For example, proper ventilation and fans allow heat and moisture to leave the greenhouse. Keep in mind that finding the right cooling solution depends greatly on the location of the greenhouse, the overall climate and weather in your region and your budget.