Graylands Phase 4 no H17 Athi-River, Mavoko -90100 Machakos
+254 790 02 02 42
X
Graylands Phase 4 no H17 Athi-River, Mavoko -90100 Machakos
+254 790 02 02 42
The general purpose of ventilation is to provide healthy air for breathing by diluting the pollutants originating in the building and maintaining temperature and humidity at comfortable levels. Removing the pollutants or diluting airborne contaminants reduce potential fire or explosion hazards in addition to providing a continuous supply of fresh outside air that distributes the air within the building or room.
To provide good air quality, enough air needs to be brought in and circulated so that it reaches all areas of the buildings.
Creating optimum environmental conditions in barns is an often under estimated success factor in modern dairy farming. Inadequate ventilation impairs the well-being of livestock. In future, the likelihood of hot summers, along with high barn temperatures, will increase. A poor indoor climate can cause heat stress and severely reduce animal comfort.
Despite which barn is right for your dairy business, each housing facticity needs to be well ventilated to achieve the following:
Warm air generated by the cows rises and exits through the adjustable chimneys in an airflow pattern called the “chimney” effect. The warm rising air by convection creates a vacuum that lets in fresh colder air from the adjustable side curtains. Adjustable chimneys ensure the correct air exchange for optimal inside climate conditions. The ceiling fans rotate slowly to create a circular air movement that pushes air toward the ceiling, thereby heating it before it reaches floor level. This ensures uniform climate conditions in the barn and fresh air for the cows without creating a cold draft.
Lack of “chimney” effect in warm periods means that most of the air exchange is created by the wind pushing air through the curtains. Curtains and chimneys will be completely open to facilitate as much air exchange as possible. For safety measures, the curtains will close in the case of strong winds and rainfall. Ceiling fans will rotate at a higher speed, creating downward air movement that cools the cows at the feeding table and in the walkway with air speed. Recirculation fans installed above the stalls cool the cows with airspeed to maximize laying time in the stalls
Natural & mechanical or hybrid systems are used to get more efficient air circulation by ventilation performance.
Ventilation air volume is determined for each premise separately considering concentration of harmful substances. Alternatively, ventilation air volume calculated be set according to the research results. If the nature and concentration of harmful substances is not possible to determine, air exchanged is calculated as following:
Vprem. – premise volume [m³]
Example: a premise with 7 m length, 4 m width and 2.8 m height. To determine the air volume required for ventilation of this premises, calculate the room volume 7x4x2.8=78.4 m³. After that determine the required efficiency of the fan using the following tables of recommended ventilation rate.
Like the lungs, buildings need to be able to breathe to make sure that fresh air comes in and dirty air goes out. Air indoors can build up high levels of moisture, odors, gases, dust, and other air pollutants. To keep the air safe indoors, fresh outdoor air is needed to dilute these indoor pollutants.
Loafing barns are basic barns that provide adequate shelter to protect livestock from all weather conditions. They are often integrated with pasture so the cows can roam in and out of the barn as they please. Getting the ventilation design right is very important in all three types of barns. Ventilation must be sufficient to prevent a build-up of harmful concentration of gases such as ammonia and CO2. However, cooling with air exchange is only as good as the incoming cooling air. When the temperature is high, especially in summer, cooling with air may be insufficient and artificial cooling (for example fans) may be required.
Any structures around your barn such as buildings, trees and silos along with the natural contour of the land will disturb airflow. This affects conditions experienced by your cows inside the structure so it’s important to make sure airflow of the site works in accord with your ventilation plan in the barn.
Structures should be situated for maximum wind exposure – located at right angles to prevailing winds to allow maximum opportunity for cross ventilation. This is typically achieved by orientating the barn east to west. Positioning your build east to west also helps solar radiation which allows more sun infiltration in winter but less in summer.
The roof of your dairy barn will need to be a minimum of 4m – 5m in height, allowing for clearance of your feed wagon. The necessary eave height of your barn will depend on the density of cows you plan to have inside.
Roof overhangs can be an important feature to help reduce sunlight exposure in hotter months and to optimise sunlight in colder months, thus minimising heat stress in summer and benefiting from sunlight in winter. The most common roof overhang measurement to achieve this is 2m – 2.5m.
Roof slope also affects the performance of a naturally ventilated building. A proper roof slope enhances air mixing within the building and the ventilation rate through the building. An ideal roof slope is 4:12 (rise: run). A shallow roof slope (less than 3:12) or a flat ceiling will reduce air movement due to buoyancy forces.
This results in stagnant air spaces, reduced ventilation rate, and increased moisture, heat, gas, and odor accumulation. A steeper roof slope can enhance the upward air movement due to buoyancy, which increases the air exchange rate. However, roof slopes greater than 6:12 can cause incoming air to exit the building before mixing with inside air, resulting in poor air mixing in the animal zone, and pockets of damp, stale, warm air. and Roof slope is 4 / 12 almost 30 Degree best between 22-28 degree recommended.
Chimneys & roof vent Versatile, sturdy, and insulating! models are SQUARE CHIMNEY, RECTANGULAR CHIMNEY, DAMPER LINEAR ROOF VENT, CHIMNEY DUCTING with bird barrier and also can be used Chimney fans
Chimney or roof outlets / Ridge Vent are the most critical part of the roof and roof design
In the perfect natural ventilation system, the ‘out’ vent is at the apex (and nowhere else) and the ‘in’ vents are as close to the ground as practical. This arrangement keeps the ‘chimney’ height as large as possible, and by doing so, not only creates the greatest air flow, but means that there is plenty of air movement near the ground where the people generally are.
In a hot climate, the cost to air condition the entire volume of a large building is often prohibitive, and without some precautions a building quickly heats up during the day via radiant heat and heat conduction. Radiant heat from the sheeting and purlins makes the inside feel hotter and a lot more uncomfortable than the building’s ambient air temperature would suggest.
The ambient air temperature is also increasing via conducted heat from the hot sheeting and purlins. This creates a ‘hot zone’ which starts at the apex and spreads downwards during the day, heating more and more of the trapped air mass inside the building. The air temperature at ground level will hit its peak by around midafternoon.
The amount of radiant heat within the building will depend on how hot the inside of the roof/wall sheeting becomes. To minimize this heating, the color of the roof should always be white, or as light a color as possible.
Roof insulation is more effective than wall insulation, however, if the building is to be cooled (or heated) then insulation to the roof, walls and even floors is essential.
Insulation reduces the temperature of the inside of the sheeting. This greatly reduces radiant heat, and reduces the warming of the high-level air.
Sandwich panels are a modular building material designed to cover buildings and structures. These panels consist of two layers that form the outer structure and ensure form, weather resistance and rigidity. They contain a core that provides thermal and acoustic insulation properties. Sandwich roof panels are among the roof products with the highest price/performance rate since they ensure thermal-humidity insulation and waterproofing.
The roof is the most essential feature of any house. It primarily protects you from adverse weather conditions. Insulation panels, when integrated into the roofing system, would help regulate indoor temperatures. It also plays a role in preserving the structural integrity of the roof.
Polyurethane is one of the most used roofing insulations in the market because of its high-quality performance and unique properties. It is derived from the reaction between a diisocyanate and polyol, giving rise to its extensive range of features. Among these is its ability to block undesirable air infiltrations while maintaining the strength and efficiency of the roof.
Dealing with high temperatures is a common challenge for Australian dairy farmers. A hot roof surface produces thermal heat which is just as stressful to cows as sunlight. You can manage thermal re-radiation in your dairy barn by choosing a highly reflective outer surface (eg Zinc cladding or a light Colorbond cladding) and light coloured inner surfaces. This will help achieve stable and consistent internal temperature conditions.
The design and construction of your new dairy barn will be the catalyst for increased efficiencies and on-farm profitability. Our dedicated dairy barn experts will help customise your specific dairy building design with a range of product options for optimal results. As well, we know it’s not all about the end product, we want you to enjoy (and gain from) the journey – design to handover.
Curtain is one of the most economical curtains for natural ventilation in livestock houses that include dairy, goat, and calf barns.
Almost all buildings have windows and structural elements but many buildings need and have additional mechanical curtain systems and special venting that can remove the pollution they produce. These breathing curtains contribute to bringing in fresh air. Ventilation above needs to carry the air outside to avoid redistributing pollutants from inside the buildings. To protect the building interior against the exterior natural phenomena such as sun exposure, temperature changes, earthquake, rain, and wind.
Fixed- Removable- Automatic adjustable curtains are applicable to most buildings where massive air flow is necessary for breathing buildings. A non-structural fabricated aluminum cladding system, found on the external walls of large multi-storey buildings.
Side ventilation systems and roll-up ventilation units are the standard solution. Not only do they offer large opening heights; the wide range of models ensures maximum flexibility. Indeed, today’s high performance roll-up ventilation systems are nothing more than the culmination of applying modern-day technology to the original ventilation principle of incorporating slots in window fronts. The roll-up units ensure that fresh air is efficiently admitted into the barn interior along the full length of the long (eaves) front. Our roll-up ventilation systems are custom-manufactured products that can be additionally fitted with temperature, wind velocity and rain sensors
Many industries now require a fresh air ventilation system to be compliant with local regulations including schools and hospitality. Adequate ventilation is also imperative for industrial and commercial plants to maintain safety and comfort, helping to eliminate excess heat, smells and potentially toxic fumes.
Without proper ventilation, buildings become prone to stagnant air, where bacteria build-up makes the indoor air more polluted than the air outside. Air quality can be affected by many impurities, such as low-level irritants (dust, pollen) right through to radon and volatile organic compounds.
In humid or colder areas, and particularly in uninsulated buildings, condensation can become a factor when humidity levels are too high. This can lead to the growth of mold growth and various health issues.
Mechanical ventilation definitely has merits over natural ventilation, but the issue comes to retrofitting a solution to a building. This could add quite a bit to the cost! Which is why, if possible, mechanical ventilation is designed into the building plans, so that the costs to implement these systems are kept to a minimum.
Mechanical ventilation helps reduce indoor air pollution, but it works best if paired with keeping known sources of air pollution out of the building. For example, the only way to reduce the effect of secondhand smoke indoors is to not allow smoking indoors or near the entrances. Some cases you need efficient ventilation to get rid of the Emissions risks.
Good ventilation is critical in maintaining an optimal growing environment and improves the overall efficiency of a greenhouse. It is essential for both good temperature and humidity management. Cooling is critical in some environments and is most commonly achieved using passive roof ventilation. The movement of hot air up and out of the roof vents pulls in cooler air.
Ventilation is also important for air circulation and replenishing carbon dioxide. Poor air circulation reduces plant activity and can lead to problems with humidity and disease management. Air movement in the greenhouse should be between 0.2 and 0.7 metres per second. If carbon dioxide levels are not maintained, plant growth is affected.
Passive ventilation uses openings (vents) curtains which naturally draw air through the greenhouse. Vents are the most common ventilation method used in greenhouse production. Roof ventilation is a more effective method of air exchange than side wall curtain ventilation. Though different designs will vary in their effectiveness, in general terms, roof vents are up to 5 times more effective than side wall vents.
For better air circulation and solution, The Green house curtains should be proper and fit your air ventilation systems and needs!
Active ventilation is the use of equipment to force air into or out of the structure. Fans are the key method of actively venting a greenhouse. Fans can also be fitted in greenhouses to move or circulate air within the greenhouse. Circulating fans are often used inside passively ventilated structures to assist air movement when venting is minimal.
