Tropical and Hot Climate Greenhouse Design: Natural Ventilation Augmented Cooling NVAC Greenhouse
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- Опубліковано 18 жов 2016
- For more information: nvactropicalgreenhouse.weebly.com
Natural Ventilation Augmented Cooling Greenhouse. An alternative approach to cooling and ventilation in hot climate greenhouses. Patented in USA, Canada and Australia.
This is another great example of utilizing natural phenomena to benefit mankind. Much respect! I would like to implement this when I build a greenhouse.
I really love this. I live in Udon Thani in Thailand and was going to build a hoop house but now I'm going to give this a go. Thank you for your video.
A greenhouse in Thailand…
3 years later, would you mind sharing your experience ?
Fascinating stuff. I have a small farm and built a small greenhouse from repurposed stuff. Building a aquaponics system. My first greenhouse was single pane plexiglass and is way to hot to do anything but dry seeds.
I love the concept, using a misting system is a smart way to go. I'm concerned that a high humidity climate wouldn't cool much though with a misting system..... I plan to explore this concept more on my channel. Thank you for the video and I hope you got your PHD
Simple Tek Thanks for the comment. Your concern is appropriate. We do limit the use of the system during humid days and I don’t recommend use of the system in regions that experience very high humidity year round. Thanks for watching and yes, I did happily get my PhD.
You could add earth tubes for a humid climate. This requires a small amount of power to ruin the fan, but is easily run with a small solar setup.
Earth tubes are simply 6" drain tubing buried under at least 3 feet of earth. You run them for as long as practical, and put one end on one side of the greenhouse, and one in the other, then install a fan. This cools the air going through the tubes.
The longer the run, the more air can be cooled.
For larger systems, you got limits on size and flow, so people then go to fluid filled pex pipe buried very deeply, and connect it to a radiator and a fan, similar to how a car engine is cooled.
Check online for details. :-)
This is underrated man. Awesome.
Respect pure from my heart
Excellent! Thank you!!
Great work, thanks!
thanks i learnt A lot
very interesting!
This is a great example of an innovative greenhouse. Are there any examples of large scale farming, ie over 2000m2 and in a multi-span large scale greenhouse?
would need a more sturdy structural design if i do that here in the Philippines considering the typhoons!
I was planning an Earth-Air heat pump, with a solar chimney to drag out warm air through Venturi effect. It will be a continuous process...no fans needed.
Lucas - great idea - are there layout drawings for the greenhouse?
Respect
This is a great example of an innovative greenhouse. Has this been tested with in a situation where carbon dioxide is fed into the greenhouse? CO2 is an input in photosynthesis and leads to significant plant growth
Very interesting but the takes are very confusing for those of us who haven't seen the system working.
Thermometer readings would have been very clarifying, perhaps a few of them in clearly defined parts of the greenhouse.
Hi. Great work here. I am very new to all these and was wondering if this is better than cool pad & fan system in terms of cooling the green house as well as maintaining appropriate humidity. Kindly enlighten me. Thank you.
Hello Adarsh. This system is comparable to a pad and fan system, but it works in a natural ventilation greenhouse i.e. very open (with mesh) sidewalls and roof vents. The NVAC also is affected by natural air movement, such as wind gusts. Pad and fan systems require a more closed design to be able to draw air through the pads, across the greenhouse and out from the fans.
So it doesn’t actually work that well in humid climates?
Question please: Tropical weather normally combines with Typhoon, does this design have vulnerability protecting against that?
If the outside RH is equal to the amount provided by the misters, will the system still work (as evaporative cooling is dependent on the differential between inside and outside RH)? Wouldn't a simple fan system with a GH tube be much cheaper, simpler, and more effective? I've seen similar designs in the tropics, however the problem here is keeping air moving and humidity down. This means a simple rain cover and a fan system. I don't believe that adding more humidity in tropical zones will be helpful, especially considering the many fungal issues present.
I live in the Big Thicket (east Texas). Is there a greenhouse design that you do recommend for our high heat high humidity?
Greenhouse ventilation system is very important
No fans needed?! You should do KW power ,financial, and sustainability test; to verify that misting is or not as useful as a simple circulatory/vent fan.
I would, as NOT all ideas are actually viable, productive or even close to sustainable.
This is perfect for the central valley CA what’s the outside vs instead wn 100 outside maybe adding geothermal underground air exchange and a side fan seems like a lot but depending on crop value....
Go Goings Depending on inside temperatures and relative humidity, we can get over 8C of cooling with significant air movement.
has this system been tested in a hot desert climate ???
I am wondering, what happened if there is a tropical heavy rain with strong winds, would that construction survive?
How is it like the weather at Barbados? Is heavy rain common?
Cool concept, wonder if I can have more info about the design. I'm planning to build greenhouse in my backyard. Thanks
Head over to nvactropicalgreenhouse.weebly.com to fill out the contact form. I'll get in touch with you through this. Thanks for inquiring.
The Philippines has five types of climates: tropical rainforest, tropical monsoon, tropical savanna, humid subtropical and oceanic (both are in higher-altitude areas) characterized by relatively high temperature, oppressive humidity and plenty of rainfall. There are two seasons in the country, the wet season and the dry season, based upon the amount of rainfall.[1] This is also dependent on location in the country as some areas experience rain all throughout the year (see Climate types). Based on temperature, the warmest months of the year are March through October; the winter monsoon brings hotter air from November to February. May is the warmest month, and January, the coolest.[2]
Is this applicable to my country.?
xinod ras The NVAC system might be applicable. It is important to note that if the humidity outside and inside the greenhouse is too high, the cooling capacity of the system is greatly reduced. If there are periods of the day where the sun is strong, temperatures are high and humidity may be lowered in and around the greenhouse (usually mid-day), the system has been proven to be effective, even in typically humid climates.
It's a nice idea but when it's monsoon and summer and humid like ur in a boiler in my region this misting is needing more adjustments. Now in hot dry summer with heat waves we then get a sudden rain it's like a climate mix in summer in my region and the need for electricity and they just assume u get water liberally....it's possible for some places but unfortunately not all...if only someone could make the green house pretty like a glass house in hot areas too....I purely wanted a green house in a terrace for it's looks to grow some flowers and look at the rain from inside....
If you are interested in testing this in a true hot climate that represents future generations I'd like to hear from you. I am in North Texas. Our temperatures spike on the high end but we have extreme low end valleys as well. Basically -6c for two months, typically an average of 29c for four months, with peak summer months sustained as much as 40-43c.
Testing in the Caribbean is useful only when accepting the uniqueness of island climates: yes it is hot during the day, but evenings drop significantly. This is true whether rainy season or dry. Regulars rains help with cooling and those are consistent regardless of season. We Texans tend to vacation across the Caribbean and Central America. ;) The local climate does a lot of the misting for you already.
To truly prove out the approach you need a climate where sustained dry seasons last up to six months with no expectation of appreciable evening drop down nor the typical and predictable showers the Caribbean enjoys in early mornings and mid to late evenings.
Hi Dave.
If you're willing on giving the NVAC technology a try, I would be thrilled to test it in more arid, summer climates such as yours. In recent months, we have been looking for a more arid climate region to test the NVAC greenhouse design. What kind of greenhouse operation are you running?
It seems like you have some experience with the climates in the Caribbean and South America. I agree that many of these areas have heavy rains combined with high temps. Barbados and other islands with similar climates are unique as they do have a rainier season, but also have a significant dry season where rain can be very rare; sometimes many weeks with nothing but small overnight showers. These periods are considered more arid. This is especially true in the past few years. In such a climate, there can be periods of weeks to months where there are no rainfalls to cool things off.
What is the best way to contact you off youtube?
Please email me through nvactropicalgreenhouse.weebly.com/contact.html
From there we can set up better communication.
@@lucasmccartney5043 hi, was this ever tested in Texas? Im in a part of Victoria Australia with a similar hot/dry climate. Im curious how it worked out as im planning on building my first 30'x100' high tunnel this fall. Any info is much appreciated, thanks.
@@paganpride464 I will have some data from a relatively large greenhouse in the middle east using the system. I can update you when the information is available. Reach out on contact form on nvactropicalgreenhouse.weebly.com
What about the tunnel effect of polytunnels
Any more research done for this? any large installation using this technic?
There has been more work done on this recently. Head to the website below and use the contact form. I will get back in touch with you. Thanks! nvactropicalgreenhouse.weebly.com
Hi, your topic is on the design of greenhouse in hot and humid climate. However, the end conclusion of the results actually shows a high RH which is detrimental to plants which I would already have guessed so from the usage of a mister. Ultimately does this serve as a solution to a good greenhouse design for hot & humid climate. Please take note I am referring to hot and humid....not hot and dry. Thanks.
Indeed the NVAC system relies on an evaporative cooling process, and so yes the performance of the system is reduced under truly humid conditions, and its use would be detrimental to the crop. However, the evaporative cooling process occurs in the rafters of the greenhouse and therefore the water droplets from the misting do not reach the foliage of the crop, only the draft of cooler air reaches the crop. Moreover, the system is automated and on humid days, the system is activated only during the peak temperature, which coincides with a sharp drop in RH in many climates, even if the overall average RH is very high. On rainy days, it may never be used.
Note that we have not tested the design in climates where the humidity never drops, but we will be shortly. The draft of cooler air, even if marginally cooler, may be beneficial even considering the high RH. Results to come.
That is a great job. Unfortunately, it is not suitable for tropical or high humidity regions. It is mainly depending on vaporation of the water to drop the temperature.
Is this commercially available now?
Will this be hurricane proof?
Hello Lucas, May I ask if this design would be more effective in a scaled-up version greenhouse(1000m2 to 2000m2) ?
It can be as effective in any size greenhouse, provided the roof and vent designs are appropriate. For example, the NVAC setup will not be the same in a multi-span large scale greenhouse compared to a single span large scale greenhouse. The shape of the roof also comes into play.
Lucas McCartney Thanks, I'm having a draft for a sustainable farming project in Vietnam and the greenhouse part is killing my budget. So I am strongly interested in this innovative design since it is a cheaper cooling solution than a fully automated greenhouse. My only concern now is that with three layers on top, will the sunlight will retain enough necessary spectrum for plants to grow?
The system in fact creates 2 layers, which usually isn't a hindrance as shading is used anyways. When designing the specific NVAC system for a greenhouse, I balance the existing shading with the added shading from the NVAC roof, to result in no overall change.
@@lucasmccartney5043 how much will it cost for a 30 feet x 60 feet green house in the Caribbean?
can you tell me if this is the kind of green house to build in El Paso, TX for growing warm tropical climate fruit trees?
The NVAC greenhouse can provide cooling and an increase in RH. If you're after a little cooling and a tropical environment for fruit trees then this might work for you, yes. I'm curious to know what type of tree crop you're considering? Sounds interesting.
@@lucasmccartney5043 was this just a video showing what can be done, or are systems like this available to the public for sale?
Bob Newhart. Until now the NVAC systems are custom built for each structure via local manufacturers or onsite using building crews. Let me know if you want more info.
Would temperate crops survive in this greenhouse in a tropical climate?
Remember humidity - trying myself to understand what's best in humid tropics...
At my place, the temperature is around 32°C (humidity around 60-70%). If I installed this design of greenhouse, how much the temperature you expected will be drop?
The performance of the NVAC system can vary depending on solar load, wind conditions and exact design of the greenhouse. In a typical natural ventilation greenhouse with large side and roof vents and under sunny and low ind conditions, you might expect 2-4 C cooling (compared to outside conditions).
Thank you sir
Hello, I am interested in your tropical greenhouse system, could you help in building one please? Ola
“Cool” idea
Yet no one figured the use of a shade clothe might actually work, as good or better? Simplest solution first.
Yes, no real control in this experiment. Quite saddening.
We still want the sunlight, not the heat.
Would it work without the misting system?
It would not work. The NVAC design relies on the cool air provided by the evaporative cooling, which in turn relies on the misting system. Thanks for the question.
What about if the outside is 45 + degrees Celsius
How much difference it can make ?
If in a dry climate, a large amount of cooling will be possible in +45C (i.e. >10C)
Can this be used along side conventional cooling methods?
Yes it can. The design of the NVAC system relies on natural ventilation, therefore open vents are critical to the performance of the NVAC system. Provided traditional greenhouse cooling methods allow for open vents, the NVAC greenhouse design could be used in combination.
go eat on a patio that has fog fans and see if they have another system to assist the fans?
Hi Lucas, are you still working on this project? Do you offer consultation?
hi i want to get more info please i want to set up a soil based greenhouse in trinidad west indies.... thanks in advance....
Hi. I'd be glad to provide more info. Check out my website nvactropicalgreenhouse.weebly.com/contact.html and contact me there. I'll get back to you by email.
If situated in a very hot, humid climate, would strawberries work with this type of system?
This greatly depends on your local climate and greenhouse design. The NVAC system might be sufficient to provide the needed level of cooling if immediate conditions are right.
hi, what about growing microgreens in hot and humid area like Tropical climates where it is not only hot but humid. the water evaporation to cool the greenhouse will pose a risk as the already high humdity will become higher for thr ,ictogreems tp grow
In an environment that is already very humid, the cooling capacity of the system is indeed diminished, as in other evaporative cooling systems. The benefit of the NVAC system is that the water droplets from the mist or fog systems will never reach the crop. If a greenhouse is very well ventilated via natural ventilation, even in a humid environment, some cooling will be gained from the NVAC system. Nonetheless, it must be used with caution to avoid over humidifying the inside climate of the greenhouse.
In Belize it is very difficult to produce tomatoes in high tunnels or tropical greenhouses the temperatures are over 35 deg Celsius and increases more in the afternoons (between 12 - 4 pm). Small farmers do not have the capacity to invest in too much equipment. It would be good if we could test this system here as we much needed. If i could get more information maybe I could do it at our research station of the Ministry of Agriculture in Belize. My name is Oscar Salazar, okisalazar@yahoo.com or oscar.salazar@agriculture.gov.bz
What is that colorful smoke for??? What is the use of that?
NoyPi RealTalk thanks for the interesting question. The colourful smoke was used to map and track the air movement per section of the greenhouse.
Lucas McCartney - Okay baby ! Thank you ❤️
I need more info on this please
Is there an email address or a messaging service I can reach you at.
Lucas McCartney I have a couple of questions. how does the misting water is preventing from getting on to the plants and how is the misting water collected for re-use. do you have a construction diagram by any chance ? thanks
Hi Zahid. As per the NVAC design, there is a roof added on the inside of the greenhouse that guides the cooled air and prevents the mist droplets from falling any further, never reaching the crop. In the video from 0:14 to 0:55, are diagrams showing this; notice a smaller roof of similar design under the left-hand side outside roof. At 3:14 is a view of this inside roof, seen above my head in the picture. The smoke tests seen in the video also show the this roof design.
This inside roof is designed as any other greenhouse poly roof would be; that is it has a gutter system for water collection. This water can be used for other purposes, mainly contributing to the irrigation needs.
Please provide an email address or other contact I could reach you at if you require more info.
Email zahidr1000@gmail.com . Thank you for your response. I live in UK but I want to build soil less based vertical green house using the Most modern yet cost effective and technological design. The temperature can be as much as 38 Celsius in summer. Utilising solar power for mist. I am also looking into uv resistant poly sheeting. If you can recommend please do. Also is the list of materials used for mist making in your report.
njdajan@gmail.com plsss... i need more info on this.
Can I get more info on this design please?
Urban Plantation you can reach me through the contact form on my website. I’ll gladly answer any questions. nvactropicalgreenhouse.weebly.com/contact.html
How many degrees can this system cool?
When used correctly and in drier climates, the system can cool up to and over 10C.
This is great, however for tropical locations? I doubt it. It wouldn’t survive a few seasons of cyclones in Aus.
What is the smoke produced from?
Hi Daniel. I used a variety of smoke emitters. The easiest to use were Titanium Tetrachloride sticks. Sold by MeterMall.
Thanks
Wonder if creating a vortex like on newer airplanes would speed the airflow over the ridge near the misters
Thanks for the interesting comment. Indeed creating more turbulence at the roof vent could promote air movement around the misters. From experimental data, there already is a great amount of turbulence in this area. Inducing even more turbulence would have an effect, for the better or the worst. Undetermined at this point.
Hi Lucas, are you still working in this field?
Yes. You can reach me at mccartney.agsolutions@gmail.com
@@lucasmccartney5043 Is this email address still functional?
Hey Luke. I would like to get in touch with you. Let me know how I could do that
Hi Zeyd. Check out the contact form at nvactropicalgreenhouse.weebly.com/contact.html and we can start from there.
Thanks. Doing that now
message sent
But this also adds 2 layers of plastic shading to the top of the greenhouse reducing natural light coming in further thats the only problem i see with it
Sir can you send me the drawing
Not practical for hot humid climes. Use shade cloth overhead, remove the walls, and ventilate. Done