TECHNICAL FIELD OF THE INVENTION:
The present invention relates to the design development of a new concept greenhouse and more particularly to ventilation systems for greenhouses which is energy efficient, easy to operate and cost effective.
BACKGROUND OF THE INVENTION: Greenhouses comprise a sturdy structure with a plastic or glass roof and similarly glass or plastic walls thereof. Generally, greenhouses are arranged in such a way as to control the environmental conditions inside the greenhouse. The solar radiation makes the portion delimited by walls warm and the plants and soil therein get heated. The greenhouses use different systems within the structure to control the environment inside the greenhouse wherein the temperature get lowered and humidity ambient, providing a microclimate optimal for the plant growth.
In greenhouse, climate control vital to the plants’ growth and development is achieved through ventilation. Ventilation reduces inside temperature during sunny days and supplies carbon dioxide, which is vital to the plants’ photosynthesis resulting in good plant growth and development. Ventilation system simply means air exchange. Large volumes of air need to be moved during hot conditions.
In general, greenhouse climate control is achieved through two types of control system- active and passive ventilation. First, the active control/ ventilation system which is also known as mechanical ventilation done by exhaust fan; another active method is use of fan and pad system, which is often employed. Low-pressure propeller blade fans are used for greenhouse ventilation. They are placed on the end of the greenhouse opposite the air intake, which is often covered by evaporative cooling pads and louvers.
Second, the passive ventilation is also known as natural ventilation and is accomplished by air coming in one side of a structure and flowing out to the other. It comprises changes in shape and orientation of the greenhouse structure in such a way so as to provide a microclimate inside the greenhouse for good plant growth and development. The system for ventilation used is natural ventilation comprises different aspects such as roof and side vents, and rollup sides system. Some greenhouses are ventilated by manually operated ventilators in the roof. This method is usually not satisfactory for ventilating plastic covered houses due to the rapid temperature fluctuations possible. Some greenhouses can be ventilated using side and ridge vents, which run the full length of the house and can be opened as needed to provide the desired temperature. This method uses thermal gradients, creating circulation due to warm air rising. Greenhouses with only side vents depend upon wind pressure for ventilation and are usually not satisfactory. The warm air must be allowed to rise through the upper vent while cooler air enters along the sides. The system of using conventional fan-powered greenhouses is not sustainable for the long run as these greenhouses involve high electricity cost and energy wastage. Moreover, in high humidity Fan & pad system becomes unable to control the temperature. Generally, fan and pad system design to gives about one volume air change/minute which keeps the ambient temperature difference between the louver end and the fan end. But it has its own drawbacks because they are costly both as initial purchase of fan, their maintenance and then the cost of electricity for the operation of the equipment. Another option is air conditioning to remain cool but using air conditioning in a large space like a greenhouse is not cost effective and high energy consumption occurs in this method too. But, keeping the greenhouse cooler is important for the crop growing in the greenhouse as the conventional greenhouse become very hot during summer and unable to serve for a crop.
The overall efficiency of a greenhouse is improved by well ventilated system maintaining an optimal growing environment. It is an important aspect of greenhouse construction and management because Poor air circulation reduces plant activity affecting the plant growth. Further, the sustainability is not achieved in a greenhouse if the weather is cloudy and sun is not there. The internal temperature of greenhouse must not be too high because it is very harmful for crops. For this, generally in greenhouses the temperature is controlled by natural ventilation (in which case the greenhouse comprises large windows) or by forced ventilation. However, windows have some downsides such as cost and heat loss. Hence, there is a need to provide a greenhouse with ventilation system which is energy efficient, cost effective and simple to operate and which can be sustainable in this region of tropical and subtropical area providing proper ventilation, temperature, humidity and volume of air inside the greenhouse for creating ambient microclimate for good plant growth. A system is required which can be advantageous and useful during winter as well as summer simultaneously. A system that provide a controlled temperature in both the conditions naturally and easily resulting in saving lot of energy which is wasted to run electrical equipment.
OBJECTIVES OF THE INVENTION: It has already been proposed that there is a need for an improved ventilation system in greenhouse which can provide the air circulation in and out of the greenhouse naturally and without the use of energy so that it may be cost effective and energy efficient. The object of the present invention is to provide a greenhouse with ventilation system which operates naturally in accordance with the outside and inside temperature differentiations of the greenhouse.
Another object of the present invention is to provide a natural ventilation system including the air movements relating to orientation/ structure with jigs and fixtures/ design of a greenhouse which will be operated in accordance with changes in the temperature in the greenhouse. Yet another object of the present invention is to provide the natural ventilation wherein the ventilation provides cost effective system, overcoming the increasing electricity cost for fan operation.
Another object of the present system is to provide more uniform cooling in the crop area. Another object of the present invention is to provide ambient atmosphere in greenhouse through ventilation by means of aerodynamic principles to provide ventilation even at the slightest wind speed. Another object of the present invention is to provide special structure to suit the natural ventilation system with the objective of energy conservation. Yet another object of the present invention is to provide improvements in construction/ design with different jigs and fixtures.
Further, the fundamental object of the invention is to provide greenhouse with novel Structural Aspect in compliance with the natural ventilation system wherein the system is used for basic intent of saving electricity.
SUMMARY OF THE INVENTION:
The present invention/ structure is designed in such a way as to maximizing natural ventilation which in turn results in the ambient microclimate inside the greenhouse. Designed with unique system of cross ventilation. Side vents is provided in both windward and leeward side of greenhouse. In this greenhouse centre bay’s
Ventilation is provided in the all sides which make it almost open from all sides. It gives a lot of open space at top and sides as compare to conventional greenhouse which in turn helps hot air to come out from top vents and cool air enters through side vents.
In this greenhouse, ventilation system is provided in such a manner that it facilitates the circulation, mixing and exchange of greenhouse air. It forms a uniform climate by dispersing and removing heat as per requirement. As ventilation is required throughout the year, and the ventilation requirement varies with the outside environment, this natural greenhouses environment control system is design as such to provide a certain summer ventilation capacity of air per square foot of floor space. Moreover, the natural ventilation system is cost effective as well as energy efficient option.
In present structural design, wind creates vacuum pressure as it blows over the roof vent causing air to be sucked out of the structure. The said ventilation system is Passive one which has no electricity requirements while still providing high ventilation rates with an even temperature gradient inside the structure. Even if there is no wind, ventilation occurs by the hot air from inside the structure rising to the top and pushing cooler air down towards the crop. This demonstrates the principal of buoyancy, commonly dubbed “hot air rises”, and is the same principle as what gives lift to a hot air balloon. Buoyancy, as applied to protected agriculture structures, occurs because moist air is denser than dry air. Though this is a relatively simple concept, two factors - structure orientation and structural design - impact the success of this natural ventilation in the structure.
Natural ventilation let the crop cools more evenly. The said system Reduce the day to day operating costs resulting in more profits so it is cost effective. A good ventilated greenhouse that is able to provide the best crop, increased profits and energy efficiency in the present scenario. The present invention Greenhouses ideally suited
for Indian conditions, with flexible ventilation system, and integration of abiotic conditions. This can be used to grow different crops in different climatic conditions.
BRIEF DESCRIPTION OF DRAWINGS:
Referring to the drawings:
The fig. 1 describes the structure, cladding and net house combination. The structure consists of eight ventilation system designed in such a way so as to provide a better cross ventilation system (air flow) to maintain temperature across the innovative structure as compared to other design innovative structure.
Fig. 2 illustrates the rear and side view of the structure showing the eight ventilation system in span.
Fig. 3 further illustrates the layout plan of the greenhouse structure and airflow during the air exchange through the ventilation system.
Fig. 4 illustrates truss view showing the pulley and gear system wherein the pulley and gear system is manually and easily operated. The special pulley like fixture makes it very easy to operate. Moreover, there is no requirement of electricity for opening of the vents.
DETAILED DESCRIPTION OF THE INVENTION:
The following detailed description provides an explanation for all the embodiments of the invention. Various inventive features are described below that can each be used independently of one another or in combination with other features.
The present embodiment comprises of various features that contribute to maintain the ambient environment of the covered structure. The innovative structure Fig.1 comprises of a combination of a polyhouse and a net house with eight ventilation
system in such a way wherein a better cross ventilation system (air flow) is achieved to maintain temperature across the whole structure naturally and equally as compared to other designs. The structure wherein the system is operated naturally without the use of electricity making it sustainable use of natural energies system. The said temperature regulation is achieved with the help of various specially designed vents and differential height of the bays. The opening and the closing of the vents have been made very easy. The special pulley like fixture (Fig-4) makes it very easy to operate as such there is no requirement of electricity for opening of the vents. Temperature inside this specially designed innovative greenhouse can be 3-4°C less than outside.
The embodiment which comprises of the said ventilation system that removes warm, moist air and replace it with drier air. The dry air helps in reducing the high humidity that generally causes moisture condensation on cool surfaces and tends to increase the occurrence of diseases, so as a result in lowered disease occurrence. Further, this natural ventilation system makes the inside climate ambient for good growth and development of the plant resulting in a good harvest. The present system provides a good air circulation which results in proper cooling, heating, CO2 replenishment, and removal of undesirable gases, such as ethylene wherein this environment provides a good crop. The said air circulation system (Fig.3 front view) work together with heating, cooling, and CO2 systems in order to obtain peak efficiency. In this way it’s a proper aerodynamic system that deliver a proper circulation of air, air exchange from outside of the greenhouse. In the present invention the improved aerodynamics is achieved by proper sizing (Fig.2, Fig-3), orientation and operation (Fig.3) and it provides better control than with fan systems. This new concept design of natural ventilation systems provide growers better control of temperature and humidity at lower cost.
The present invention is intended to provide a system for air circulation without
consuming energy; the said system comprises the change in shape and design of the structure (Fig. 1, 2, 3) therein, where in it results in formation of a ventilation system through which air exchange even at a certain minimal speed of outside air without the use of electrical energy is possible. The invention further describes that the temperature regulation is because of specially designed vents and differential height (Fig.4) of the bays which is resulted by the various innovative jigs and fixtures design. The opening and the closing of the vents is done manually which is very easy to operate. Ventilation is Top fixed and on sides manually operated for opening and closing.
The present invention provides a natural ventilation system in greenhouse with cost-effectiveness and energy efficiency. The height described in Fig.4 of this particular structure significantly impact air circulation. The venting capacity of greenhouses has more venting capacity than the floor area. Ventilation is provided in the all the opposite sides as shown in Fig.2. In this greenhouse centre bay’s ventilation is provided in the all sides which make it almost open from all sides. It gives a lot of open space at top and sides as compare to conventional greenhouse which helps hot air to come out from upper vents and cool air enters through side vents. (Fig.3) Temperature inside this greenhouse is generally 3-4°C less than outside and no electricity requirement for regulation of vents.
The greenhouse, wherein the greenhouse is provided with a ventilation system comprising means for air circulation through drawing the air inside of the greenhouse, and wherein displacing the indrawn air in all the direction of the greenhouse, wherein the ventilation system also comprises structural orientation of the outer covering of the greenhouse with specially designed and developed Jigs and fixtures in the greenhouse thereof.
It works on the principle of wind and thermal buoyancy for air movement. The concept of thermal buoyancy is based on the physical properties of air; as air is heated
it has the natural tendency to rise. As the temperature rises within the greenhouse the hot air rises and escapes through the top vents. This process creates a vacuum that draws cooler air into the greenhouse through the sidewall vents located at the appropriate height from the ground. (Fig.3,4) Wind passing over the top vents on a greenhouse also creates the same vacuum effect and draw fresh air into the sidewall vents. This greenhouse provides both advantages of net house and greenhouse.
Further, this inventive structure has been specially designed for cultivation of horticultural crops. The ventilation system in present system is designed in such a way that there is better cross ventilation system (air flow) to maintain temperature all across the greenhouse. The invention comprises of specially designed vents and differential height of the bays where in this design results in the temperature regulation. The greenhouse is built in such a way so as to have a multi height with multi span to facilitate the cross ventilation. (Fig.1) It is very useful where the temperature is higher.
The invention describes a greenhouse structure wherein three number of bays (Fig.1,2,3,4) are arranged in a special fashion as to providing the natural ventilation inside the greenhouse. The said structure is made of three bays at the width of various heights; having an innovative structure width with a corridor. The greenhouse comprising the incorporation of multi height which in return facilitate the cross ventilation.
All Structure, Rafters, Perlins and Trusses are hot dip galvanized and design to take a wind load up to 100 km/h and more and standardized design. The innovative structure is strong enough to withstand at high wind velocity. The other structure includes rolling-up sides with manual systems work well for warm season ventilation. The present system is arranged in a way where in heavy cool air near the floor becomes lighter as it is heated and rises towards the roof, also on cool days the large temperature difference creates excellent air exchange. The greater the temperature
difference between inside and outside, the greater is the air movement. It also provides buffering of the air and reduces quick changes in temperature. The present embodiment contains the orientation in such manner as to intercept the normal summer wind along the sidewall.
The invention is having the structure, cladded with UV Stabilized polystructure material with maximum light transmission where in the cladding material is a combination of the 200 micron UV stabilized poly film and 50 mesh net. Therein the cladding material is movable. This has been attached with the structure by a specially designed profile and accompanying PVC SVR profile, SVR lock profile and the spring which click into it. The structure is further enclosed with the 40 mesh Insect proof net to prevent entry of insect pests. The combination of all the jigs and fixtures comprises of GI pipes with latest ZAP Technology. Nuts and other metallic parts Includes all the elements required for joining and water tightens components (such as fittings, clamps, screws and nuts plated against corrosion). The structure comprises of three open door, complete clear polyethylene, top & bottom tracks, jambs, flashings. The embodiment also comprises of shading containing 75% shading net (agro shade net) with rolling arrangement connecting pipe etc. and it can be rolled up when not required. This innovative structure is totally energy efficient.
Further, an embodiment is oriented in such a crucial manner so as to maximize the efficiency of cross ventilation. The said structure is designed in a way so that for gutter-connected multi-spans, a combination of windward side vents and continuous leeward roof vents tends to result in the most effective ventilation design where in the retractable roof designs the open windward side vents to achieve cooling.
The said structure is designed in a manner to provide the plants a good sunlight resulting in successful growing of plants where in the cladding material can provide a minimum of 2,000 foot candles (fc) of full, unobstructed sunlight. There is no need to provide supporting light provided the weather is clear which most of the time is in
tropical condition. This creates a possibility to extend the growing season, fresh fruits, flowers & vegetables all-round the year. In this specially designed new concept greenhouse it works like a protective structure with proper greenhouse functions without requirement of energy during winter and providing proper ventilation to distribute the even airflow in summer as it opens all vents and act like net house also. Temperature is controlled as it become open to all sides. And hence save lot of energy which is wasted to run electrical equipment. The system comprises special type of pulley and gear box system which is very easy to operate its vent. Even user can open/close top vents very easily from ground and no staircase is needed.
This new concept greenhouse is built in taking the account of other factor also wherein it is constructed in such a manner so as to avoid the waterlogging and provide the proper drainage of water. The interior pad of the structure is in level with a slight slope to the exterior for drainage. The pad is high enough to prevent excess rain water from flowing into the structure.
The said structure comprises of proper water availability to ensure successful production. An outside irrigation source is provided because crops will obviously not receive moisture from rainfall. It is ensured that each plant requires two liters of watering as single application. With that in mind, proper watering can be provided in the said system. Drip Irrigation can also be provided in this system through gravity system by putting storage tank at higher level than the green house floor level. Moreover, additionally this innovative structure can be connected to the central irrigation and fertigation system for appropriate irrigation and fertigation. When provided an optimum growing environment, a plant will produce the highest yield of the highest quality. The system comprises of all the essential factors that contribute to such an environment to provide for optimum growth and development. The present system enable to optimize plant growth with the appropriate available resources.
The new concept design comprises of various innovative Jigs and fixtures related to
the structure. Jigs and fixtures are developed in such a manner so as to provide dependable solution for the development of this innovative production facility for high quality produce. The economical production of engineering components attached in the greenhouse are facilitated by the developed jigs and fixtures. The use of a fixture has made a fairly simple operation out of one which would otherwise require a lot of skill and time. Both jigs and fixtures present in this greenhouse are positioned components accurately and held components rigid and prevented movement during working in order to impart greater productivity and part accuracy, such fixtures held or gripped the work piece in the predetermined manner of firmness and location, to perform on the work piece a manufacturing operation. The correct relationship and alignment between the tool and the work piece has been maintained, the jigs and fixtures are accurately made and the material used is able to withstand wear and the operational (cutting) forces experienced during metal cutting. Jigs and fixtures developed are the precision tools for the designing of this greenhouse.
The ventilation system is designed so as to provide better cross ventilation system (air flow) to maintain required temperature across the innovative structure. The temperature regulation is controlled by providing specially designed vents and differential height of the bays with help of above explained jigs and fixtures. The natural ventilation system controls the greenhouse environment by flowing ambient air from outside the greenhouse into the inside environment according to the temperature of inside of the greenhouse, re-circulating air back and through. This method for controlling the temperature within a greenhouse comprises flowing air into the greenhouse from outside the greenhouse to reduce the temperature. Warm air is flowed outside the greenhouse and the circulation take place till the temperature therein is at the desired level. The embodiment contains specially designed and developed Jigs and fixtures in to support the ventilation system so as to modify the structure to circulate the air to the ambient environment.
The present invention provides a combination of structural members, use of jigs and fixtures, combination of proportions of membranes, bay width, and orientation of the whole structure results in controlling the environment inside the greenhouse by providing the ambient temperature with the help of air circulation saving the electricity cost. Temperature is lowered, humidity is increased and watering needs are reduced. The innovative structure comprising special features to suit different requirements with the basic objective of energy conservation. The design of natural ventilation systems will provide growers better control of temperature and humidity at lower cost.
The above disclosure is non-limiting and modifications and variations are possible without departing from the spirit and scope of the invention. Since other modifications and changes varied to fit particular operating requirements and environments are apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.

We Claim:
1. A greenhouse with a natural ventilation system comprising a new design made with help of variation in bay height and width, eight natural vent system, greenhouse pulley and gear system, greenhouse new design jigs and fixture system and greenhouse entry system, greenhouse dual covering system for the energy saving, cost effective and easy to operate natural ventilation for good growth and development of plants for an increased yield.
2. A greenhouse with a natural ventilation system as claimed in claim 1, further comprising: i. The upper part of the greenhouse with main span having difference in height providing an upper space for an easy to operate vent, and roof of the greenhouse supported by the frame structure having longer life span and good strength.
ii. The frame is designed with the help of innovative jigs and fixtures wherein these jigs and fixtures together with the frames of various heights provide this structure.
3. The greenhouse system as claimed in claim 1 or 2, wherein the greenhouse natural ventilation is provided with help of eight vents, therein the air is drawn from outside through side vents and then inner warm air comes out from the upper innovative vent, maintaining the temperature and microclimate inside the greenhouse, therein the vents are sealed with 40 mesh net which allow air but not insects and pest.
4. The greenhouse system as claimed in claim 3, wherein the inside greenhouse temperature is maintained at lower than the outside temperature in hot summer days of tropical and subtropical region.
5. The greenhouse system as claimed in claim 1 or 2 or 3, wherein the vents are operated with the help of pulley with an easy operating mechanism from the base of the greenhouse itself.
6. The greenhouse system as claimed in claim 1 or 2, wherein the greenhouse cladding material is dual comprising of PVC providing the maximum sunlight and strength and 40 Mesh Net.
7. The greenhouse system as claimed in claim 1 or 2, wherein the greenhouse dual cladding material serves the dual purpose of this greenhouse by making it work as net house also.
8. The greenhouse system as claimed in claim 1 or 2, wherein the greenhouse comprises of a buffer room at the entry of the greenhouse to prevent the pests.
9. The greenhouse with natural ventilation system as claimed in claim 1, wherein the greenhouse base is concrete base that is made of square shaped cement blocks.
The greenhouse with natural ventilation system as claimed in claim 1, wherein the greenhouse is free from electricity requirement and thus it is energy saving and cost effective.