Are you building a homemade polyfim greenhouse, but are unsure about how to ventilate it? Here are a couple of solutions for you. You can see that this greenhouse has roll up sides, an option which is readily available, but can be costly. We have 2 options available that insert directly into your polyfilm covering without any additional framing. They use the channel base and wiggle wire to insert directly into the greenhouse covering. You simply cut the film and install these accessories directly into the film covering without any additional framing.
Intake Shutter with Solar Powered Opener
The first option is a solar powered greenhouse shutter. This has louvers and a wax cylinder powered opener. It will open when it is warm and close when it is cool automatically. They are available in 6 different sizes. If you would like to use this on another type of greenhouse such as polycarbonate, we can remove the base channel and you can insert this directly into a wood framed opening.
Solar Powered Roof Vent
The second way to do this is with a solar powered roof vent. This is a lightweight polycarbonate vent. It weighs less than 10 pounds, but you get all of the benefits of the durable polycarbonate covering. It also has the was cylinder powered opener that will automatically open and shut the vent as the temperature requires. To install this you simply cut the polyfilm and install it directly into the greenhouse covering.
A lot of people prefer to build their own greenhouses rather than purchase a kit. With these 2 ventilation options, there is no reason not to build your own polyfilm greenhouse.
There are many benefits to polyfilm greenhouses. One thing is that some municipalities will consider this a temporary structure and will not require permits, wind and snow load ratings, etc. They are also less expensive than a rigid polycarbonate covered greenhouse. One disadvantage to this is that most of the greenhouse polyfilm found today has a 4 year UV protection, so you will have to figure on replacing the covering every so often. Double polyfilm greenhouses consist of 2 layers of polyfilm with an air inflation system for greenhouse film blowing air between the 2 layers. This will give you a much better R rating than just a single layer of film. Manufacturers claim that it can save you up to 40% of your energy costs. That is quite a considerable savings. I find that the inflated film is more rigid and less susceptible to damage than a single layer of film. This all happens without lowering the light transmission properties of the polyfilm. This is an excellent choice that has been used by many commercial growers through the years and is totally acceptable for a backyard greenhouse operation. Be sure to use greenhouse polyfilm that is UV protected and has an anti condensate coating on it. If the film is not UV protected you should not expect to get any more than one years use out of it, sometimes even less. The anti condensate coating keeps droplets from forming on the film. This will contribute to the overall health of your plants. Any condensation that does form on the roof will come off in sheets rather than in droplets. If you have water dripping on your plants you will have damage to your leaves, fruits, flowers and overall less healthy plants. So, when considering your first or next greenhouse, take a look at a double polyfilm greenhouse and see what benefits it will give you.
We are happy to announce the newest product addition to our greenhouse glazing line. This covering is a vinyl material that has a crystal clear, glass like clarity. It is great for commercial operations that would benefit from the customers being able to see clearly inside the greenhouse. Every fall it seems that I get a couple of calls from people wanting to “seal up” their screened in back porches for the winter. But, they do not want the semi transparency of our 6 mil, 4 year polyfilm. This is a perfect covering for this purpose. It is a tough, durable 16 mil covering. Of course all of the greenhouse glazing materials we offer have UV protection. The life expectancy of this material is 4 years. It comes in 54″ widths and 3 different lengths of rolls.
The same thing happens every year about this time. We are all still enjoying the warm weather of summer, getting the kids ready for school, and we forget about our beloved plants. I can’t tell you how many times in the past that Tom and I were installing greenhouses in the cold of the winter because they didn’t get ordered in time. Typically a greenhouse that is manufactured for you will take from 4 – 6 weeks for delivery. In the fall these lead times become extended, causing delays from the expected delivery times. This not only applies to greenhouses, it applies to polycarbonate sheets as well. They are typically delivered in 1 – 2 weeks, but in the fall they will take a week or sometimes longer past these times. So, even though it is really hard to think about it right now, if you are considering purchasing or building a greenhouse this fall, now is the time to start your decision process and get an order placed. Trust me, this I know from years of experience.
Building a Polyfilm Greenhouse? Not sure how to attach the film to your greenhouse frame? This video discusses the use of batten tape or base and wiggle wire systems. They are both excellent for wood frames. The wiggle wire system is good for metal frames as well. As always, we hope you find this edition of “The Greenhouse Minute” informative and helpful.
I received a really nice email from a gentleman the other day who had read one of my previous articles regarding greenhouse accessories. He pointed out to me that he did not use the accessories in exactly the same way as I outline in my article. This just served as a reminder to me that greenhouse growing is indeed a learning curve for all of us. Here’s the thing – We all live in different climates. We are all growing different plants. It is up to us as greenhouse owners to learn how to supply the necessary climate in the area we live in. He mentioned that he only used his heater at night in his location. I would dare to say that someone in Wisconsin growing tomatoes in the winter would totally disagree with this. He also mentioned an evaporative cooling system. He was in a location with a desert type climate. I can see where that would work for him. But here, in Louisiana we have just about 100% humidity (I am sure it just feels that way) all summer long. An evaporative cooling system is totally ineffective here. He also considered a shade cloth as an optional accessory. I consider it an absolute necessity. That is, if you are using your greenhouse at any time except in the winter months. If you have it shut down in the spring, summer and fall, I would not really suggest getting one. When someone calls me asking about greenhouses and accessories, I recommend that they at least get a ventilation system at the same time, as it is installed into the greenhouse frame. This is easier as an initial installation than it is as a retrofit. I don’t like loading greenhouses up with a whole lot of equipment that you may not need at a later time. I suggest adding additional accessories one at a time and as the need arises. Of course don’t wait for the last minute, because everyone else will be in need at the same time. For custom made items such as a shade cloth, this can lead to a delayed lead time. The thing is, we are buying a greenhouse maybe for practical reasons, but most of us are purchasing them for our love of growing. So relax, take the time, learn what you need in your area, for your plants to make your greenhouse a success. And as always, keep growing!