The problem with "permanent" shade cloth is the loss of light/heat in the winter. Regardless of the brand, if you are shading 50%, as with the aluminet R 50%, you will be losing not only 50% of the light, but also 50% of the incoming heat. It will be a definite plus in the summer, and a definite minus in the winter. A better option is something that can be removed in the winter, or at least rolled up, and out of the way of the limited incoming sun/heat. The source of supplemental heat, propane in your case, is not a factor. The Aluminet 50 will increase your winter heating costs if left in place during the cold, but otherwise sunny, period, and dramatically reduce incoming light and plant growth.

Another problem with a winter cover is the chafing of the poly which leads to faster deterioration. Manufacturers recommend no permenant winter cover. If you can't find the shade cloth anywhere else I sell it (knitted 50% for .20 cents a square foot). It comes in a 12 foot width. I make an sell 10' and 12' wide hoop houses out here in Washington state and try to carry the ground and shade cloths for customers. Good luck in your new ghouse Shad

I've been hoping for some clarification on the pros and cons of leaving Aluminet shadecloth in place during the winter. I have read in this forum that it's best to remove it for the winter, but I've been confused by this website, which says that one of the benefits of Aluminet is it works as a thermal blanket, reflecting "invisible heat radiation" back into the greenhouse at night, helping to maintain warmer temperatures. I notice that this page does not mention either summer or winter, which has added to my confusion.

I've read that Aluminet is most efficient at reducing summer heat gain when used on the outside of the greenhouse, but I have mine installed inside, hanging a few inches below the roof. (My thought was, if this works passably well for me, I won't have to battle keeping it attached to the outside during our wicked winds.)

As an aside, I have in fact kept mine up all winter, but I think I must have an odd situation that would not apply to the original poster. My problem here in the desert is too much light and too much heat, even on sunny winter days; without the shadecloth I'd definately have scorching even in winter. In fact, I thought 40% would be enough for me since I grow succulents requiring bright light. I know now that in my bright and hot climate I should have ordered at least 50%.

Anyway, I thought I'd mention that website link above. I don't know that Shad has read that website, but it has definately had me a bit muddled as I tried to understand the winter/summer issue with Aluminet.
Sheri

In reading the aluminet web link, it is easy to see how one could get confused. The problem with the examples at the link is that they sometimes are refering to a shade cloth and sometimes a thermal blanket. Thermal blankets are made to be installed inside a GH, and for use at night. The thermal (night) blanket is then rolled up in the day. Some commercial sized operations use these, and have fairly expensive mechanisms to roll out and in the blanket daily.
The links example concerning shade cloth getting hot and not keeping the GH cooler would only be true if the shade cloth were on the inside. Proper installation, if the idea is to reduce heat load, is for shade cloth to be on the outside.
Finally, having gone to NMSU, I understand your situation with the climate. Even where I live, I usually use a 30% shade cloth in the winter, and switch to 60% in the summer.

Thank you cuestaroble, I re-read the web page after reading your link, and it makes much more sense now. Your info about alternating different shadecloth densities is helpful too. My husband thinks we may end up moving the Aluminet outside, as you said. The experimentation and learning continues...

Thanks also, Shad, for letting me duck into your thread.

No problem for jumping in. I am trying to figure this out myself. My customer handed me a book that has aluminet in it with a description that leaving it on in the winter keeps heat in. It may keep heat in from a heat source (propane heater) but if it blocks to much light and heat from external sources (sun) than is it doing an good leaving it up all winter?
Thanks for the replies,
Shad

Here is a link to pictures of the greenhouse to give everybody an idea of what I am dealing with.
monahanbuilders.com click on the exterior page.
Thanks,
Shad

While it would not be easy to install I think that the best cooling would be to use the aluminet and put it on poles or something that suspended it a couple feet above the roof.
This would allow the wind to blow through and cool the area between the roof and the shade cloth.

I left my shade cloth on this winter and the only drawback that I saw to it was that if we had ice, it stuck to the shadecloth and I had to turn on the heat a little while to melt it off because of the weight. I did that so that I wouldn't have to pull white poly to overwinter perennials and it worked like a charm. I use 40%. If you're not actively growing/heating in there, you don't need all that heat(light) getting in there anyway.

I suggest you contact the Alunminet folks; they are helpful and knowledgeable. They have a factory in the San Diego area, but also a distributor in FL. Ultimately what will be a determining factor for you will be the reqirements of your plants growing inside, and your location.

I kept my shadecloth on all winter in so cal. I originally thought it would block out too much light, but my husband convinced me that it would retain warmth inside the gh at night, requiring less juice to heat. So I kept it on and monitored the light. The plants did not appear to suffer for any less light. [I should state that I am growing orchids, most of which require a bit less water, light and food in the winter.] I have the shadecloth edges finished, and grommet holes along the tape; I placed eye-screws along the base of the gh to hold it in place. It has not been a problem to keep it on. During the very dead of winter, I did unhook the shadecloth from the base. I rolled it around a long dowel, up to the gh eaves. I tied it about every foot along length of the two sides, and the strength of the Aluminet held the ties. This let direct light in the gh sides for the darkest month--but reqires monitoring to see when the sun becomes stronger, at which point I unrolled the dowel and re-hooked it to the base. I left the shadecloth on the top throughout, to prevent heat loss.

Besides IGUSA, I also bought from Growers Supply. Price is about the same, and no sales tax for you. I bought some shade for my mom's small greenhouse a few years ago. It worked out well, but as others said, not good to leave up year round. I'm looking at Aluminet for my cold frame recently. Gentleman by the name of Joe Niche seemed to know what he was talking about. By the way, for retain the heat, did you investigate something like Bubble Greenhouse Insulation?